document_title: Captain America's shield

question_text: what material is captain america's shield made out of

question_tokens: what material is captain america 's shield made out of

text: Captain America's shield

text: Abilities[edit]

text: Vibranium proto-adamantium alloy[edit]

text: Captain America's shield is virtually indestructible under normal conditions;[1] while cosmic and magical or godly opponents have broken the shield, the shield proves strong enough to absorb Hulk's strength, and repel an attack from Thor's mystical hammer Mjölnir without any visible damage. As it is made of vibranium, it is able to absorb all kinetic energy and transfers very little energy from each impact, meaning Captain America does not feel recoil or transferred impact forces from blocking attacks. These physical properties also means the shield can bounce off of most smooth surfaces, ricocheting multiple times with minimal loss in aerodynamic stability or velocity. The shield can also absorb the kinetic impact of a fall, allowing Captain America to land safely even when jumping off of several stories, as can be seen in Captain America: Winter Soldier movie when he escaped from the S.H.I.E.L.D.'s STRIKE squad by jumping off an elevator.[volume & issue needed]

text: Ricochet ballistics[edit]

text: A common misconception is that the shield can "magically" return to Captain America[citation needed]. The "superhuman serum" that enhanced Captain America's physical attributes also improved his mental faculties—such as cognition, perception, balance, aim, and reflexes—to near genius-level. This allows him to instantly calculate ballistic-physics and predict the probable trajectory of objects in motion. This makes him a perfect shot. He can dodge or deflect bullets with his shield without collateral ricochet to civilians, to calculate where or how the shield will bounce and when it will return to his location, or trip a running person to cause them to fall into a specific position.[citation needed] In Avengers: Age of Ultron, he pulls the shield back to him after it is stuck, but this is through an electromagnet fastened on his arm. After his memories are altered to make him believe that he is a Hydra sleeper agent, Rogers uses his precise knowledge of the shield to put Sam Wilson, its current wielder, in a position where he will fail to save a senator from Flag-Smasher by arranging for Wilson to be forced to throw the shield in a manner that Rogers knows from his own experience will miss its target by mere millimetres, as part of his agenda to undermine Sam's status as Captain America.[2]

text: Original shield[edit]

text: In his debut, Captain America (secretly U.S. Army Private Steve Rogers) is equipped with a triangular, badge-shaped shield made from vibranium. After complaints by rival comic-book publisher MLJ that the design was too similar to that of its own patriotic hero the Shield,[3] Timely Comics replaced the triangular shield with a disc-shaped one.

text: While the origin and fate of the original shield were not described in the original comics from the 1940s, the shield's fate was revealed decades later in 2001 through a retconned story. According to the tale, King T'Chaka of the African nation Wakanda met Captain America in early 1941 and gave him a second sample of vibranium, an alien metal with unique vibration absorption properties and found only in Wakanda and the Savage Land.[4] The new Vibranium sample was used to make Captain America's circular shield and his triangular one was retired.

text: Captain America received a second triangular shield that he used until given his disc-shaped shield, which was personally presented to him by President Franklin Roosevelt.[5] This second triangular shield would be kept in storage with Rogers' other personal effects after the war. It was recovered at some point after Rogers joined the superhero team the Avengers in The Avengers #4, and was kept at Avengers Mansion. It was destroyed by the supervillain Mr. Hyde during a raid on the mansion by Baron Zemo's Masters of Evil, and later "plucked from time" and restored by Zemo in Thunderbolts #105 (Oct. 2006). The shield (along with other sentimental items thought destroyed) was returned to Captain America. A third triangular shield is kept in the Smithsonian Institution. It was used by Captain America when he foiled a terrorist attack on the museum itself after the loss of his usual shield; it was then given to him in gratitude. This shield is destroyed several issues later by a Kree alien warrior.

text: The shield destroyed by Hydra and restored by Zemo was eventually passed on to Elijah Bradley, the teenage hero known as the Patriot and leader of the Young Avengers.

text: Revised history[edit]

text: In 2010, the history of the original shield was revised. In the limited series Captain America/Black Panther: Flags of Our Fathers, Captain America, Sergeant Nick Fury and the Howling Commandos meet Azzari (grandfather of T'Challa) -- the Black Panther and king of Wakanda during World War II. Aided by Wakandan military forces, they successfully repel a series of Nazi assaults led by the Red Skull and Baron Strucker. During the battle, the Red Skull (wearing a battle-suit) crushes the triangular shield, and Captain America uses a circular vibranium shield provided by T'Chaka to incapacitate the Skull. The weapon serves as the inspiration for the circular shield that the super-soldier begins using upon his return to America, and the encounter marks the beginning of friendly relations between the United States and Wakanda.[6]

text: Circular shield[edit]

text: The circular shield most associated with Captain America made its debut in Captain America Comics #2 (April 1941). A concavo-convex metal disc approximately 2.5 feet (0.76 m) in diameter, is indestructible and has remained his most constant shield over the decades.[citation needed]

text: In Captain America #255 (March 1981), it is established that the shield was presented to Rogers by President Franklin D. Roosevelt.[7] The shield is created by a fictional American metallurgist named Myron MacLain, who had been commissioned by the US government to create an indestructible armor material to aid the war effort. MacLain experiments with the indestructible vibration-absorbing metal vibranium.[4]

text: During one of his experiments to fuse vibranium with an experimental iron alloy [8] MacLain falls asleep and awakens to find that the resulting alloy had set in a tank hatch mold. It was then painted to become Captain America's symbol. MacLain would later attempt to recreate the shield's metal to no avail, his experiments instead eventually yielding the super-metal adamantium.[citation needed]

text: Rogers' indestructible shield is more durable than regular adamantium and one of the most indestructible objects in The Marvel Universe. Carl "Crusher" Creel, The Absorbing Man, once absorbed the properties the shield while battling The Avengers. The vibranium grants the shield unusual properties, allowing it to absorb all of the kinetic impact and vibrations from any blows that the shield receives without injuring Rogers in the process.The proto-adamantium allows the shield to be stronger than the strongest Adamantium.The vibranium is also a factor in the way Rogers throws his shield: he often uses it to ricochet and strike multiple opponents or stationary objects with little loss of velocity in its forward movement after each impact.[citation needed]

text: When Rogers returns from suspended animation, Tony Stark "improves" the shield by incorporating electronic and magnetic components in it so that Rogers can even control it in flight. Rogers soon discards the additional components because he finds that it upsets the balance of the shield when thrown.[citation needed]

text: After Rogers' death, Stark takes over custody of the shield, with one replica on display in a museum, and another replica buried with Rogers. The real one is kept by Stark to be used by the new Captain America, whenever they deem it appropriate to train a new one. After failing to find a S.H.I.E.L.D. agent capable of throwing it properly, Stark offers the shield to Clint Barton (known at that time as Ronin), who does manage to throw it. During a confrontation involving the Young Avengers, he scolds Kate Bishop for using the Hawkeye name. She tells him that the "Real Cap" gave her that name in honor of his at the time dead friend, so this leads Barton to refuse to be Captain America.[9] The shield is subsequently stolen by the Winter Soldier, who did not want anyone else to carry the shield. Inevitably, in an effort to honor Rogers' last wishes, Stark offers to let the Winter Soldier (Bucky Barnes) keep the shield, and to serve as the new Captain America. Bucky accepts. This offer is made "off the books", and only the two of them, the Black Widow, and the Falcon, are aware of the situation.[10]

text: Although Bucky attempted to return the shield to Rogers after his resurrection, Rogers let Bucky keep it as he felt that he could do more good in his new role as Commander Steve Rogers rather than Captain America, using a photonic shield in its place when circumstances called for him to go into combat. He reclaimed the shield for good after Bucky was apparently killed during the Fear Itself event- Bucky really going underground after his past as the Winter Soldier was exposed-, which also resulted in the shield being broken and reassembled by Asgardian blacksmiths, who add some of the mystical metal Uru to the reconstructed shield, making it even stronger than before, although it is left with a noticeable scar that Rogers decided to keep to give the shield character.[11] This premise was not observed in subsequent storylines, or considered canon, as artists have not continued depicting the shield with the scar.[12]

text: JLA/Avengers[edit]

text: In the 2003-2004 Marvel Comics/DC Comics inter-company crossover limited series JLA/Avengers, Superman is given the shield by Captain America to wield in battle in the final confrontation with Krona, and is impressed with its might. When he asks where he could get one just like it while battling foes, Thor replies, "Enjoy it while thou canst, Superman. There is none other like it in all the worlds". Throughout the final battle, the shield changes forms between the pointed shield and the circular shield due to various temporal ripples caused by Krona's equipment, and Superman even loses the shield altogether at one point when he morphs into his energy form while Cap reacquires the photonic shield, although the metal shield reappears on Superman's arm after he morphs back into his regular form.

text: Destruction of the shield[edit]

text: Over time the shield has been damaged or destroyed several times within the confines of the Earth-616 continuity, though they are not considered canon:

text: In The Avengers #215–216, the Molecule Man used his total control over matter to disintegrate the shield, along with Thor's hammer, Iron Man's armor, and the Silver Surfer's board. After he does so, he comments that the board's molecules are "weird", and while there are "odd forces interweaving" among the hammer's molecules, the shield is "weirdest of all". He later reassembles these items, with the exception of the armor, as the electronic circuits are too complicated for him to understand at that time.[13]

text: During the 1984-1985 Secret Wars limited series, the shield is partially destroyed by Doctor Doom, who has stolen the power of the godlike being known as the Beyonder. Even broken, Rogers is able to wield what is left as an effective weapon, with the shield largely retaining its balance when thrown. When the Beyonder reclaims its power, the heroes are temporarily granted the ability to realize their wishes. Rogers uses this to reconstruct the shield.[14]

text: During the 1991 miniseries The Infinity Gauntlet, Thanos, who possesses near-omnipotence via the Infinity Gauntlet, shatters the shield with a blow of his fist while in combat with Captain America. The shield is soon restored by Thanos' alleged granddaughter, Nebula, when she obtains the Gauntlet and uses it to undo the events of Thanos's temporary godhood, resulting in her erasing the death and destruction that Thanos had caused over the previous 24 hours.[15]

text: Due to a stray molecule being out of place when Rogers reconstructed the shield using the Beyonder's residual power, a vibranium 'cancer' was introduced to the shield, spreading with each subsequent impact until it finally shattered after it was retrieved from the bottom of the ocean. Learning that the vibranium cancer would require the destruction of the shield in order to cure it, Rogers took the shield to the main vibranium deposit in Wakanda so that he could use a device created by Tony Stark to halt the 'cancer' before it could contaminate the Wakandan vibranium and destroy the world, only to be intercepted by the villain Klaw, who sought to absorb the power and become stronger. Fortunately, the amount of energy Klaw had absorbed was released when he struck the shattered shield with full force after Rogers picked it up on reflex, resulting in Klaw unintentionally restoring the shield to its original state, realigning its molecules and destroying the cancer.[16]

text: In Avengers Vol. 3 #63 (March 2003), an enraged Thor, wielding the Odinforce, scrapes the shield. Thor later repairs it.[17]

text: In Thor Vol. 2 #73 (January 2004) an enraged King Thor with Rune Magic, destroyed the shield, killing Steve Rogers with it.[18] This timeline was later erased in Thor Vol. 2 #79.[19]

text: During the 2011 miniseries Fear Itself, the Serpent, the Asgardian god of fear and brother to Odin, breaks it in half with his bare hands.[20] After the battle, the shield is repaired by Asgardian dwarves and Tony Stark with added Asgardian uru-infused enhancements and Stark's own technology to make it stronger, though a scar is left, and the dwarves are unable to repair it. Stark offers a solution to the scar, but Rogers declines, saying that it "gave the old girl a little bit of character". This premise was not observed in subsequent storylines, or considered canon, as artists have not continued depicting the shield with the scar.

text: Other shields[edit]

text:
While Rogers was asleep in suspended animation, three other men used the identity of Captain America, all using steel replicas of the discus shield. The 1950s Captain America was placed in suspended animation after becoming mentally unstable. By the time he was revived years later, Rogers had returned. When the two clashed, the 1950s Captain America's shield was broken.[volume & issue needed]
In the 1980s, in a story written by Mark Gruenwald, Rogers chose to resign his identity rather than submit to the orders of the United States government and took the alias of "The Captain" instead. During this period, the role of Captain America was assumed by John Walker, the former Super-Patriot, who used both the costume and the indestructible shield.[21] In his new identity of "The Captain", Rogers initially used a pure adamantium shield provided by Tony Stark, but a falling out between the two as a result of the "Armor Wars" storyline led Rogers to return it. He then began to use a pure vibranium shield provided by the Black Panther. When Rogers returned to his Captain America identity, Walker became the U.S. Agent and returned the shield to him. Walker would go on to have his own array of different shields over the years, the first of which appeared to be the last vibranium shield Rogers was using as the Captain. The U.S. Agent used shields with an eagle motif and one in the shape of a star, as well as a photonic energy shield.[volume & issue needed]
At one point, when Rogers was exiled from the United States and was briefly unable to use his shield, Sharon Carter provided him with a photonic energy shield designed to mimic a vibranium matrix. This shield was also able to turn into an energy staff that could be used as a weapon.[volume & issue needed]
During the time when the shield was lost in the Atlantic, Rogers tried using a pure adamantium shield, but was unable to get used to the balance. He also tried fighting without a shield but also found it awkward. While up against HYDRA agents in the Smithsonian, he picked up the triangular shield that was being exhibited there and used it for a time before it was crushed by a Kree warrior.[volume & issue needed]
Sharon Carter next provided him with another photonic shield, but one whose shape could be controlled to morph the energy field into a wider force field, a bo staff or even fire a projection of the shield. While he enjoyed the versatility, Rogers noticed a number of drawbacks, particularly its inability to ricochet. Rogers gave one of the energy shield gloves to a freedom fighter in an oppressive future he traveled to and received a replacement from S.H.I.E.L.D. when he got back to his own time. The photonic shield was eventually lost again in a confrontation with Ultron when Hank Pym's use of vibranium resulted in the destruction of the generator that created the shield,[22] leading to Rogers finally reacquiring his original shield.[volume & issue needed]
In Secret Avengers, he uses a new energy shield which could be generated on either arm, or both, and was able to be thrown and ricochet off surfaces to hit targets before it dissipates, preventing enemies from using it against him. A new shield would be generated moments later. Moon Knight, who had acquired a copy of the technology, had it described to him as a "zero point energy shield".[23]
A British analogue, Captain Midlands, wields a golden circular shield in the design of the traditional lion symbol of Britain and coated in an Anti-Magic nanominium gloss.[24]
In Captain America: Steve Rogers, Steve wields a new version of the triangular shield that can deploy an energy blade on its pointy end and can be divided in two, allowing him to use both halves in combat.[25]

text: Other versions[edit]

text:
In the 1998-1999 time travel mini-series Avengers Forever, various future and alternate versions of Captain America are shown with many different variations of the shield.[26]
Cable claims to have borne the shield into battle many times during his early adulthood, far in the future. In another version, Cable claims that the origin of his techno-organic arm was because his original one was lost when he attempted to retrieve the shield as a symbol for morale in the future war against Apocalypse.[27]
In the future timeline of the Guardians of the Galaxy, the shield is used by Major Victory in battle.[28]
In the Future Imperfect setting, where the Hulk becomes the Maestro and is both the last surviving superbeing and a despotic ruler, an ancient Rick Jones assembles a trophy room as a tribute to the fallen heroes, with the shield among them. Jones uses the shield to defend against one of the Maestro's blows, but the wheelchair used by the disabled Jones was not sturdy enough for such an impact. Jones is sent flying back and is impaled on Wolverine's skeleton. When the Hulk, plucked from the past, throws the shield to attack his future self, he manages to injure the Maestro, causing a large gash on his chest as he attempts to cut the Maestro in half. Throwing the Hulk off, the Maestro attempts to hit Hulk with the shield himself, commenting that Rogers could never throw the shield hard enough to do him any damage, but the Hulk deflects it with the Silver Surfer's old board. After the battle, Jones is cremated and the Hulk poured Jones' ashes over the shield, affixing it with an epoxy. The Hulk then throws it into space, hoping that it will land somewhere exciting.[29]
In the Marvel manga stories, Captain America uses a photonic shield before his death in Volumes 1 and 2, and his bodyguards use shields of metal. The shield also appears in the Rings of Fate mini-series, having been acquired by Carol Danvers after Elektra stole it from Avengers Mansion when she uses the costume of Captain America.
In the Colonel America reality of Marvel Zombies, the shield is held by the last humans, who have formed a new society. As part of a self-defense program, the shield is used by the semi-sentient body/mind configuration of Colonel America's body and the son of Black Panther. It is also used by Forge, who is fighting in Iron Man's old armor. The shield and many zombie allies of the humans are lost in the dimensions due to a traitor.[30]
Captain Mexical is an alternate world version of Captain America from a dimension where the Aztec empire never fell. He is kept in the mainstream Marvel universe. His shield is used by Machine Man as a weapon during a zombie incursion; Mexical himself is slain.[31]
In Mark Millar's 2008-2009 "Old Man Logan" storyline in Wolverine, the Red Skull has a trophy room filled with artifacts belonging to the heroes of the Marvel Universe. Captain America's shield is at the center of the trophy room, and is later used by Wolverine to decapitate the Red Skull.[32]
Within the third and fourth issues of Avengers and Power Pack Assemble! miniseries, the Power Pack were thrown ten years into the future and met older versions of themselves, including a 25-year-old Alex Power. In those issues he shows greater control over his powers, (such as being able to deconstruct an enemy powered-armor suit), and now wields Captain America's shield.[33]
In the Age of Ultron story, Captain America is shown sitting in a storeroom in the base of the last remaining active heroes, with the shattered fragments of his shield around him.[34]

text: In issue #7 of the Marvel series Strikeforce: Morituri the shield is stored in a trophy room belonging to the alien "Horde" invaders.[35]

text:
Ultimate Captain America uses a shield of pure adamantium, although that metal may not possess the same properties in the Ultimate Marvel universe as it does in the mainstream Marvel Universe.[36] The shield was destroyed when Gregory Stark smashed it with Thor's hammer, though Captain America would wield another later.[37]

In Ultimate Nightmare, Ultimate Captain America encounters his Russian counterpart, who has been driven mad due to being trapped in an underground complex for many years. He has created a "replica" of the shield, which turns out to be made out of scrap metal and human remains and grafted directly onto his forearm, and which proves far less powerful than Captain America's own shield.[38]

In the alternate reality shown in What If...? #114, where the heroes and villains are unable to leave Battleworld at the conclusion of the Secret Wars, the shield is passed on to the daughter of Captain America and Rogue.[39]

text: In other media[edit]

text:
In the 1970s Captain America TV movies, Steve Rogers is given a transparent plexiglass shield painted with concentric stripes (red and clear transparent) and a central star. The shield was designed to act as the windscreen for his motorcycle, but could be detached and used in its traditional offensive / defensive role when Rogers goes on foot. Furthermore, the shield can apparently return to Rogers in a smooth arc when thrown without needing to be ricocheted and with enough force to knock a man down in the return path.
In 2003, the company Factory X released a line of licensed prop replicas of items from the Marvel Universe. An aluminum replica of Captain America's shield was among their initial line up of props, and was limited to a production of 2,525 pieces.
In the closing of the March 12, 2007 episode of The Colbert Report, Stephen Colbert read a letter from Joe Quesada in response to Colbert's earlier comments toward Captain America. He was then presented with what was said to be Captain America's indestructible shield, reportedly willed to Colbert in the event of Cap's "death". The shield was originally credited to be one of the Factory X replicas, but this is not the case. The shield given to Colbert was originally acquired by the long-time writer and editor (and late) Mark Gruenwald, who either commissioned it or received it as a gift. It eventually found its way into the hands of Marvel Editor Tom Brevoort, and was kept in his office until being passed on to Colbert. In a pre-show conversation with a studio audience, Colbert, speaking out of character, said that when his wife saw the shield and the accompanying note, she started crying. He confessed he was a little bemused by her reaction to a fictional character sending a prop shield to a fictional version of himself. The shield was put on display hanging on the wall along with other trophies on The Colbert Report set for every episode afterwards. After The Colbert Report ended, the shield was moved to the set of Colbert's next talk show, The Late Show with Stephen Colbert where it was put on display since.
In the animated movie Ultimate Avengers, based loosely on The Ultimates, Captain America uses a shield made from vibranium and adamantium compound. Captain America used his triangular shield throughout World War II, only gaining the disc-shaped vibranium-bearing shield after he awoke in the present day. The composition of the triangular shield remains unrevealed. It did prove to be effective against the bullets of German soldiers, but was dented by the punch of a Chitauri taking the form of Herr Kleiser.
In the 2010 iOS game Infinity Blade, the player has the option to purchase a shield called The Patriot. The design of the shield, featuring three concentric rings, a star in the center, and what appears to be red, white, and blue paint all but completely worn off, closely resembles Captain America's shield.
In the video game Marvel Heroes, Captain America is a playable character and uses the shield defensively and offensively, blocking attacks and attacking with it as a bludgeoning and thrown weapon.
In the Avengers: Earth's Mightiest Heroes episode "A Day Unlike Any Other", Loki uses his magic to shatter Captain America's shield while taunting him. In the episode "Behold... The Vision!", Captain America's shield is restored by the Black Panther and scientists in Wakanda using the Vibranium machine that fused the pieces back together.
The adamantium/vibranium version of the shield becomes the main plot device for the story in the Ultimate Spider-Man episode "Not a Toy".

text: Marvel Cinematic Universe[edit]

text: Captain America's shield is a recurring image throughout the Marvel Cinematic Universe franchise:

text:
In the 2008 film Iron Man, a partially completed replica of Captain America’s shield appears approximately 1 hour 25 minutes into the movie at the point where Pepper Potts comes in on Tony Stark trying to get out of his damaged armor; the shield is visible in the distance below Tony's right arm. According to a tie-in comic, Tony's father Howard Stark created the shield. Tony subsequently used the alloy of a prototype to create his armor.[40]
In the 2008 film The Incredible Hulk, a deleted opening scene features the shield and Captain America buried in ice. However, the 2011 film Captain America: The First Avenger reveals this scene, or at least the appearance of Captain America to be non-canon.
In the 2010 film Iron Man 2, Tony Stark is building a particle accelerator in his home to create a new element for his arc reactor when S.H.I.E.L.D. Agent Phil Coulson finds the replica of Captain America's shield that was seen on Tony's work table in the first Iron Man film and asks if it is what he thinks it is. Stark ignores the question and asks him to hand the shield over, using it as a shim to level the accelerator.
In the 2011 film Captain America: The First Avenger, the round shield (along with Rogers himself) is found by S.H.I.E.L.D. agents in the Arctic within a crashed aircraft in the present day. During World War II, Steve Rogers uses an ornamental version of the triangular shield during a musical tour promoting War Bonds, which he then uses in his first field mission and is rendered useless when Johann Schmidt punches a large dent in it. He later notices an unadorned vibranium shield among Howard Stark's proposed weapons, which Stark says is stronger than steel and weighs only one third as much. Although it is merely a prototype that Stark did not intend for one of Rogers' weapons, Rogers decides to use it after it is painted into the familiar red, white and blue pattern. The shield is later on board the Valkyrie when Rogers crashing the bomber, and becomes frozen along with him in the Arctic.
In the 2012 film The Avengers, Captain America wields the same shield as the one seen in Captain America: The First Avenger.[41] While described in the prequel film as being vibration-absorbent, it is shown here as being rather vibration-reflecting, as the kinetic force from Mjolnir striking the shield rebounds as a powerful shockwave, leveling a small section of heavily forested area in the process. It is also capable of deflecting Iron Man's repulsor blasts against a band of Chitauri invaders.
In the teaser trailer for the 2013 film Iron Man 3, Trevor Slattery has a tattoo resembling the shield on the back of his neck. Slattery's tattoo is visible in the Marvel One-Shot short film All Hail the King.
In the 2014 film Captain America: The Winter Soldier, Rogers takes advantage of the vibranium's properties by jumping out of a building a few dozen stories up, and landing on the shield, thereby surviving without any serious injuries. During his street battle with the Winter Soldier, Rogers temporarily loses the shield to his adversary, with the Winter Soldier wielding it momentarily. Near the end of a confrontation with the Winter Soldier, the shield falls into the Potomac River, but appears again next to the Captain's bed as he is recovering in a hospital.
A 2014 promo for the television series Agents of S.H.I.E.L.D. features the show's logo superimposed over Captain America's shield.[42]
The shield appears in the season finale of Agent Carter when Howard Stark was being hypnotized by Johann Fennhoff and sees Peggy Carter holding Captain America's shield, asking him to bring Steve home.
In the 2015 film Avengers: Age of Ultron, the handles of the shield have been replaced with magnetic elements, allowing Captain America to control the shield and call it back to his gauntlets. Its status as a vibranium construct is referenced when the Avengers determine that Ultron is heading to Wakanda, as vibranium is the only thing from Wakanda that Ultron could want. During his later fight with Ultron, Rogers briefly loses his shield when it is thrown from the top of the truck where he was fighting Ultron, but Black Widow grabs it and returns it to its owner. When Wanda Maximoff triggers a vision of Tony Stark's greatest fear, he sees all of the other Avengers dead and the shield broken next to Rogers.
In the Agents of S.H.I.E.L.D. episode "The Singularity", Coulson, now director of S.H.I.E.L.D. has an energy shield attached to his prosthetic hand, which is similar to Captain America's energy shield in the comics.[43]
In the 2016 film Captain America: Civil War, Captain America continues to use his shield, although it is confiscated when he is apprehended for aiding the Winter Soldier in violation of the Sokovia Accords. Sharon Carter returns the shield to him, and he uses it in combat with Iron Man and his allies. Black Panther, whose weapons feature vibranium as well, scratches the shield in combat with Captain America. During the final battle featuring Captain America and the Winter Soldier fighting Iron Man, Rogers uses the shield to severely damage Tony Stark's armor, breaking open the helmet and destroying the suit's arc reactor. Ultimately, Captain America leaves his shield behind when Stark berates him for not being deserving of it, since Rogers kept the knowledge of the Winter Soldier killing his parents from him.


document_title: Food irradiation

question_text: who makes the rules about irradiation of food

question_tokens: who makes the rules about irradiation of food

root

text: Food irradiation

text: Uses[edit]

text: Irradiation is used to reduce or eliminate the risk of food bourne illnesses, prevent or slow down spoilage, arrest maturation or sprouting and as a treatment against pests. Depending on the dose, some or all of the pathogenic organisms, microorganisms, bacteria, and viruses present are destroyed, slowed down, or rendered incapable of reproduction. Irradiation cannot revert spoiled or over ripened food to a fresh state. If this food was processed by irradiation, further spoilage would cease and ripening would slow down, yet the irradiation would not destroy the toxins or repair the texture, color, or taste of the food.[18] When targeting bacteria, most foods are irradiated to significantly reduce the number of active microbes, not to sterilize all microbes in the product. In this respect it is similar to pasteurization.

tag: p

text: Irradiation is used to create safe foods for people at high risk of infection, or for conditions where food must be stored for long periods of time and proper storage conditions are not available. Foods that can tolerate irradiation at sufficient doses are treated to ensure that the product is completely sterilized. This is most commonly done with rations for astronauts, and special diets for hospital patients.

text: Irradiation is used to create shelf-stable products. Since irradiation reduces the populations of spoilage microorganisms, and because pre-packed food can be irradiated, the packaging prevents recontamination into the final product.[1]

text: Irradiation is used to reduce post-harvest losses. It reduces populations of spoilage micro-organisms in the food and can slow down the speed at which enzymes change the food, and therefore slows spoilage and ripening, and inhibits sprouting (e.g., of potato, onion, and garlic).[19]

text: Food is also irradiated to prevent the spread of invasive pest species through trade in fresh vegetables and fruits, either within countries, or trade across international boundaries. Pests such as insects could be transported to new habitats through trade in fresh produce which could significantly affect agricultural production and the environment were they to establish themselves. This "phytosanitary irradiation"[20] aims to render any hitch-hiking pest incapable of breeding. The pests are sterilized when the food is treated by low doses of irradiation. In general, the higher doses required to destroy pests such as insects, mealybugs, mites, moths, and butterflies either affect the look or taste, or cannot be tolerated by fresh produce.[21] Low dosage treatments (less than 1000 gray) enables trade across quarantine boundaries[22] and may also help reduce spoilage.

text: Public perception[edit]

text: Irradiation has been approved by many countries. For example, in the U.S. the FDA has approved food irradiation for over fifty years. However, in the past decade the major growth area is for fruits and vegetables that are irradiated to prevent the spread of pests. In the early 2000s in the US, irradiated meat was common at some grocery stores, but because of lack of consumer demand, it is no longer common. Because consumer demand for irradiated food is low, reducing the spoilage between manufacture and consumer purchase and reducing the risk of food borne illness is currently not sufficient incentive for most manufactures to supplement their process with irradiation.[3] Nevertheless, food irradiation does take place commercially and volumes are in general increasing at a slow rate, even in the European Union where all member countries allow the irradiation of dried herbs spices and vegetable seasonings but only a few allow other foods to be sold as irradiated.[23]

text: Although there are some consumers who choose not to purchase irradiated food, a sufficient market has existed for retailers to have continuously stocked irradiated products for years.[24] When labeled irradiated food is offered for retail sale, these consumers buy it and re-purchase it, indicating that it is possible to successfully market irradiated foods, therefore retailers not stocking irratiated foods might be a major bottleneck to wider adption of irrated foods.[24] It is however, widely believed that consumer perception of foods treated with irradiation is more negative than those processed by other means[4] and some industry studies indicate the number of consumers concerned about the safety of irradiated food decreased between 1985 and 1995 to levels comparable to those of people concerned about food additives and preservatives.[25] Even though is it is untrue "People think the product is radioactive," said Harlan Clemmons, president of Sadex, a food irradiation company based in Sioux City, Iowa.[26] Because of these concerns and the increased cost of irradiated foods, there is not a widespread public demand for the irradiation of foods for human consumption.[3]

text: Impact[edit]

text: Irradiation reduces the risk of infection and spoilage, does not make food radioactive, and the food is shown to be safe, but it does cause chemical reactions that alter the food and therefore alters the chemical makeup, nutritional content, and the sensory qualities of the food.[3] Some of the potential secondary impacts of irradiation are hypothetical, while others are demonstrated. These effects include cumulative impacts to pathogens, people, and the environment due to the reduction of food quality, the transpiration and storage of radioactive goods, and destruction of pathogens, changes in the way we relate to food and how irradiation changes the food production and shipping industries.

text: Immediate effects[edit]

text: The radiation source supplies energetic particles or waves. As these waves/particles pass through a target material they collide with other particles. Around the sites of these collisions chemical bonds are broken, creating short lived radicals (e.g. the hydroxyl radical, the hydrogen atom and solvated electrons). These radicals cause further chemical changes by bonding with and or stripping particles from nearby molecules. When collisions damage DNA or RNA, effective reproduction becomes unlikely, also when collisions occur in cells, cell division is often suppressed.[1]

text: Irradiation (within the accepted energy limits, as 10 MeV for electrons, 5 MeV for X-rays [US 7.5 MeV] and gamma rays from Cobalt-60) can not make food radioactive, but it does produce radiolytic products, and free radicals in the food. A few of these products are unique, but not considered dangerous.[27]

text: Irradiation can also alter the nutritional content and flavor of foods, much like cooking.[27] The scale of these chemical changes is not unique. Cooking, smoking, salting, and other less novel techniques, cause the food to be altered so drastically that its original nature is almost unrecognizable, and must be called by a different name. Storage of food also causes dramatic chemical changes, ones that eventually lead to deterioration and spoilage.[28]

text: Misconceptions[edit]

text: A major concern is that irradiation might cause chemical changes that are harmful to the consumer. Several national expert groups and two international expert groups evaluated the available data and concluded that any food at any dose is wholesome and safe to consume as long as it remains palatable and maintains its technical properties (e.g. feel, texture, or color).[6][7]

text: Irradiated food does not become radioactive, just as an object exposed to light does not start producing light. Radioactivity is the ability of a substance to emit high energy particles. When particles hit the target materials they may free other highly energetic particles. This ends shortly after the end of the exposure, much like objects stop reflecting light when the source is turned off and warm objects emit heat until they cool down but do not continue to produce their own heat. To modify a material so that it keeps emitting radiation (induce radiation) the atomic cores (nucleus) of the atoms in the target material must be modified.

text: It is impossible for food irradiators to induce radiation in a product. Irradiators emit electrons or photons and the radiation is intrinsically radiated at precisely known strengths (wavelengths for photons, and speeds for electrons). These radiated particles at these strengths can never be strong enough to modify the nucleus of the targeted atom in the food, regardless of how many particles hit the target material, and radioactivity can not be induced without modifying the nucleus.[27]

text: Chemical changes[edit]

text: Compounds known as free radicals form when food is irradiated. Most of these are oxidizers (i.e., accept electrons) and some react very strongly. According to the free-radical theory of aging excessive amounts of these free radicals can lead to cell injury and cell death, which may contribute to many diseases.[29] However, this generally relates to the free radicals generated in the body, not the free radicals consumed by the individual, as much of these are destroyed in the digestive process.

text: When fatty acids are irradiated, a family of compounds called 2-alkylcyclobutanones (2-ACBs) are produced. These are thought to be unique radiolytic products. Most of the substances found in irradiated food are also found in food that has been subjected to other food processing treatments, and are therefore not unique. Furthermore, the quantities in which they occur in irradiated food are lower or similar to the quantities formed in heat treatments.[6][7][10][11]

text: The radiation doses to cause toxic changes are much higher than the doses used to during irradiation, and taking into account the presence of 2-ACBs along with what is known of free radicals, these results lead to the conclusion that there is no significant risk from radiolytic products.[5]

text: Food quality[edit]

text: Ionizing radiation can change food quality but in general very high levels of radiation treatment (many thousands of gray) are necessary to adversely change nutritional content, as well as the sensory qualities (taste, appearance, and texture). Irradiation to the doses used commercially to treat food have very little negative impact on the sensory qualities and nutrient content in foods. When irradiation is used to maintain food quality for a longer period of time (improve the shelf stability of some sensory qualities and nutrients) the improvement means that more consumers have access to the original taste, texture, appearance, and nutrients.[30][31][32] The changes in quality and nutrition depend on the degree of treatment and may vary greatly from food to food.[19]

text: There has been low level gamma irradiation that has been attempted on arugula,[33] spinach,[34] cauliflower,[35] ash gourd,[36] bamboo shoots,[37] coriander, parsley, and watercress.[38] There has been limited information, however, regarding the physical, chemical and/or bioactive properties and the shelf life on these minimally processed vegetables.[32]

text: Organic advocacy groups believe that irradiated food should not be labeled as raw because the process changes the nutritional content of food.[39][40] However, the degradation of vitamins caused by irradiation is similar to or even less than the loss caused by other raw food preservation processes. Other processes like chilling, freezing, drying, and heating also result in some vitamin loss.[19]

text: The changes in the flavor of fatty foods like meats, nuts and oils are sometimes noticeable, while the changes in lean products like fruits and vegetables are less so. Some studies by the irradiation industry show that for some properly treated fruits and vegetables irradiation is seen by consumers to improve the sensory qualities of the product compared to untreated fruits and vegetables.[19]

text: Quality Impact on Minimally Processed Vegetables[edit]

text: Watercress (Nasturtium Officinale) is a rapidly growing aquatic or semi aquatic perennial plant. It contains health promoting phytochemicals endowed in therapeutic properties.[41] Because chemical agents do not provide efficient microbial reductions, watercress has been tested with gamma irradiation treatment in order to improve both safety and the shelf life of the product.[42] It is traditionally used on horticultural products to prevent sprouting and post-packaging contamination, delay post-harvest ripening, maturation and senescence.[32]

text: In a Food Chemistry food journal, scientists studied the suitability of gamma irradiation of 1, 2, and 5 kGy for preserving quality parameters of the fresh cut watercress at around 4 degrees Celsius for 7 days. They determined that a 2 kGy dose of irradiation was the dose that contained most similar qualities to non-stored control samples, which is one of the goals of irradiation.[30] 2 kGy preserved high levels of reducing sugars and favoured PUFA; while samples of the 5 kGy dose revealed high contents of sucrose and MUFA. Both cases the watercress samples obtained healthier fatty acids profiles.[31] However, a 5kGy dose better preserved the antioxidant activity and total flavonoids.[32]

text: Long-term impacts[edit]

text: If the majority of food was irradiated at high-enough levels to significantly decrease its nutritional content, there would be an increased risk of developing nutritionally-based illnesses if additional steps, such as changes in eating habits, were not taken to mitigate this.[43] Furthermore, for at least three studies on cats, the consumption of irradiated food was associated with a loss of tissue in the myelin sheath, leading to reversible paralysis. Researchers suspect that reduced levels of vitamin A and high levels of free radicals may be the cause.[44] This effect is thought to be specific to cats and has not been reproduced in any other animal. To produce these effects, the cats were fed solely on food that was irradiated at a dose at least five times higher than the maximum allowable dose.[44]

text: It may seem reasonable to assume that irradiating food might lead to radiation-tolerant strains, similar to the way that strains of bacteria have developed resistance to antibiotics. Bacteria develop a resistance to antibiotics after an individual uses antibiotics repeatedly. Much like pasteurization plants, products that pass through irradiation plants are processed once, and are not processed and reprocessed. Cycles of heat treatment have been shown to produce heat-tolerant bacteria, yet no problems have appeared so far in pasteurization plants. Furthermore, when the irradiation dose is chosen to target a specific species of microbe, it is calibrated to doses several times the value required to target the species. This ensures that the process randomly destroys all members of a target species.[45] Therefore, the more irradiation-tolerant members of the target species are not given any evolutionary advantage. Without evolutionary advantage, selection does not occur. As to the irradiation process directly producing mutations that lead to more virulent, radiation-resistant strains, the European Commission's Scientific Committee on Food found that there is no evidence; on the contrary, irradiation has been found to cause loss of virulence and infectivity, as mutants are usually less competitive and less adapted.[46]

text: Misconceptions[edit]

text: Some who do not advocate food irradiation argue the safety of irradiated food is not scientifically proven because there are a lack of long-term studies [47][48] in spite of the fact that hundreds of animal feeding studies of irradiated food, including multigenerational studies, have been performed since 1950.[5] Endpoints investigated have included subchronic and chronic changes in metabolism, histopathology, function of most systems, reproductive effects, growth, teratogenicity, and mutagenicity. A large number of studies have been performed; meta-studies have supported the safety of irradiated food.[5][6][7][8][9]

text: The below experiments are cited by food irradiation opponents, but either could not be verified in later experiments, could not be clearly attributed to the radiation effect, or could be attributed to an inappropriate design of the experiment.[5][19]

text: India's National Institute of Nutrition (NIN) found an elevated rate of cells with more than one set of genes (polyploidy) in humans and animals when fed wheat that was irradiated recently (within 12 weeks). Upon analysis, scientists determined that the techniques used by the NIN allowed for too much human error and statistical variation; therefore, the results were unreliable. After multiple studies by independent agencies and scientists, no correlation between polyploidy and irradiation of food could be found.[19]

tag: ul

text: Indirect effects of irradiation[edit]

text: The indirect effects of irradiation are the concerns and benefits of irradiation that are related to how making food irradiation a common process will change the world, with emphasis on the system of food production.

text: If irradiation was to become common in the food handling process there would be a reduction of the prevalence of foodborne illness and potentially the eradication of specific pathogens.[49] However, multiple studies suggest that an increased rate of pathogen growth may occur when irradiated food is cross-contaminated with a pathogen, as the competing spoilage organisms are no longer present.[50] This being said, cross contamination itself becomes less prevalent with an increase in usage of irradiated foods.[51]

text: The ability to remove bacterial contamination through post-processing by irradiation may reduce the fear of mishandling food which could cultivate a cavalier attitude toward hygiene and result in contaminants other than bacteria. However, concerns that the pasteurization of milk would lead to increased contamination of milk were prevalent when mandatory pasteurization was introduced, but these fears never materialized after adoption of this law. Therefore, it is unlikely for irradiation to cause an increase of illness due to nonbacteria-based contamination.[52]

text: Treatment[edit]

text: Up to the point where the food is processed by irradiation, the food is processed in the same way as all other food. To treat the food, they are exposed to a radioactive source, for a set period of time to achieve a desired dose. Radiation may be emitted by a radioactive substance, or by X-ray and electron beam accelerators. Special precautions are taken to ensure the food stuffs never come in contact with the radioactive substances and that the personnel and the environment are protected from exposure radiation.[53] Irradiation treatments are typically classified by dose (high, medium, and low), but are sometimes classified by the effects of the treatment[54] (radappertization, radicidation and radurization). Food irradiation is sometimes referred to as "cold pasteurization"[55] or "electronic pasteurization"[56] because ionizing the food does not heat the food to high temperatures during the process, and the effect is similar to heat pasteurization. The term "cold pasteurization" is controversial because the term may be used to disguise the fact the food has been irradiated and pasteurization and irradiation are fundamentally different processes.

text: Treatment costs vary as a function of dose and facility usage. A pallet or tote is typically exposed for several minutes to hours depending on dose. Low-dose applications such as disinfestation of fruit range between US$0.01/lbs and US$0.08/lbs while higher-dose applications can cost as much as US$0.20/lbs.[57]

text: Process[edit]

text: Typically, when the food is being irradiated, pallets of food are exposed to a source of radiation for a specific time. Dosimeters are placed on the pallet (at various locations) of food to serve as a check and ensure that the correct dose was achieved.[53] Most irradiated food is processed by gamma irradiation.,[58] however the usage of electron beam and X-ray is becoming more popular as well [1]. With gamma irradiation, special precautions are taken because gamma rays are continuously emitted by the radioactive material. In most designs, to nullify the effects of radiation, the radioisotope is lowered into a water-filled storage pool, which absorbs the radiation but does not become radioactive. This allows pallets of the products to be added and removed from the irradiation chamber and other maintenance to be done.[53] Sometimes movable shields are used to reduce radiation levels in areas of the irradiation chamber instead of submerging the source.[citation needed] For x-ray and electron irradiation these precautions are not necessary as the radiation is generated by electricity, the source of the radiation can be switched off.[53]

text: For x-ray, gamma ray and electron irradiation, shielding is required when the foods are being irradiated. This is done to protect workers and the environment outside of the chamber from radiation exposure. Typically permanent or movable shields are used.[53] In some gamma irradiators the radioactive source is under water at all times, and the hermetically sealed product is lowered into the water. The water acts as the shield in this application.[citation needed] Because of the lower penetration depth of electron irradiation, treatment to entire industrial pallets or totes is not possible.[citation needed]

text: Dosimetry[edit]

text: The radiation absorbed dose is the amount energy absorbed per unit weight of the target material. Dose is used because, when the same substance is given the same dose, similar changes are observed in the target material. The SI unit for dose is grays (Gy or J/kg). Dosimeters are used to measure dose, and are small components that, when exposed to ionizing radiation, change measurable physical attributes to a degree that can be correlated to the dose received. Measuring dose (dosimetry) involves exposing one or more dosimeters along with the target material.[59][60]

text: For purposes of legislation doses are divided into low (up to 1 kGy), medium (1 kGy to 10 kGy), and high-dose applications (above 10 kGy).[citation needed] High-dose applications are above those currently permitted in the US for commercial food items by the FDA and other regulators around the world.[61] Though these doses are approved for non commercial applications, such as sterilizing frozen meat for NASA astronauts (doses of 44 kGy)[62] and food for hospital patients.

text:
Applications By Overall Average Dose

Application
Dose (kGy)

Low dose (up to 1 kGy)
Inhibit sprouting of bulbs and tubers
0.03–0.15 kGy

Delay fruit ripening
0.03–0.15 kGy

Stop insect/parasite infestations to help clear quarantine
0.07–1.00 kGy

Medium dose (1 kGy to 10 kGy)
Delay spoilage of meat[a]
1.50–3.00 kGy

Reduce risk of pathogens in meat[a]
3.00–7.00 kGy

Increase sanitation[b] of spices[63]
10.00 kGy

High dose (above 10 kGy)
Sterilization[c] of packaged meat[a]
25.00–70.00 kGy

Increase juice yield[citation needed]

Improve re-hydration[citation needed]

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text: Technology[edit]

text: Electron irradiation uses a stream of electrons accelerated by an electric voltage or radio frequency wave to a velocity close to the speed of light. Electrons have mass and negative electric charge, and therefore electron beams at the energies allowed for food irradiation do not penetrate into the product beyond several centimeters, depending on product density. Therefore, electron beams are preferred for thin products

text: Gamma irradiation involves packets of light (photons) that originate from radioactive decay of atomic nuclei. Gamma rays are used for products that are too thick for treatment with electron beams. Every radioactive element gives rise to Gamma rays with specific energies characteristic of the source element, these rays have zero mass and no electrical charge. The ones used for food irradiation are able to penetrate through food products. The radioactive isotope radioisotope cobalt-60 is used as the source in all commercial scale gamma irradiation facilities.[58] Gamma irradiation is most widely used technology because the deeper penetration of the gamma rays enables administering treatment to entire industrial pallets or totes (reducing the need for material handling) and it is significantly less expensive than using an X-ray source. Cobalt-60 is bred from cobalt-59 using neutron irradiation in specifically designed nuclear reactors.[58] In limited applications caesium-137, a less costly alternative recovered during the processing of spent nuclear fuel, is used as a radioactive source. Insufficient quantities are available for large scale commercial use. An incident where water-soluble caesium-137 leaked into the source storage pool requiring NRC intervention[64] has led to near elimination of this radioisotope.

text: Irradiation by X-ray is similar to irradiation by gamma rays but the rays produced have a distribution of energetic packets of light, still the maximum energy of the produced X-ray photon is limited by the energy put into the X-ray generator therefore it is possible to guarantee that no partials capable of inducing irradiation can be emitted. X-rays are generated by colliding accelerated electrons with a dense target material (this process is known as bremsstrahlung-conversion), and the X-rays so produced have a spectrum characteristic of the dense target material. Heavy metals, such as tantalum and tungsten, are used because of their high atomic numbers and high melting temperatures. Tantalum is usually preferred versus tungsten for industrial, large-area, high-power targets because it is more workable than tungsten and has a higher threshold energy for induced reactions.[65] Like electron beams, X-rays do not necessitate the use of radioactive materials and can be switched off when not needed.[66] X-rays ability to penetrate the target is similar to gamma irradiation. X-ray machines produce better dose uniformity than Gamma rays, and their penetration depth is similar to slightly greater than that of gamma rays, but they require much more electricity as only as much as 12% of the input energy is converted into X-rays.[58]

text: Cost[edit]

text: The cost of food irradiation is influenced by dose requirements, the food's tolerance of radiation, handling conditions, i.e., packaging and stacking requirements, construction costs, financing arrangements, and other variables particular to the situation.[67] Irradiation is a capital-intensive technology requiring a substantial initial investment, ranging from $1 million to $5 million. In the case of large research or contract irradiation facilities, major capital costs include a radiation source, hardware (irradiator, totes and conveyors, control systems, and other auxiliary equipment), land (1 to 1.5 acres), radiation shield, and warehouse. Operating costs include salaries (for fixed and variable labor), utilities, maintenance, taxes/insurance, cobalt-60 replenishment, general utilities, and miscellaneous operating costs.[57][68] Perishable food items, like fruits, vegetables and meats would still require to be handled in the cold chain, so all other supply chain costs remain the same.

text: Standards & regulations[edit]

text: The Codex Alimentarius represents the global standard for irradiation of food, in particular under the WTO-agreement. Member states are free to convert those standards into national regulations at their discretion,[citation needed] therefore regulations about irradiation differ from country to country.

text: The United Nations Food and Agricultural Organization (FAO) has passed a motion to commit member states to implement irradiation technology for their national phytosanitary programs; the General assembly of the International Atomic Energy Agency (IAEA) has urged wider use of the irradiation technology.[citation needed]

text: Labeling[edit]

text: The provisions of the Codex Alimentarius are that any "first generation" product must be labeled "irradiated" as any product derived directly from an irradiated raw material; for ingredients the provision is that even the last molecule of an irradiated ingredient must be listed with the ingredients even in cases where the unirradiated ingredient does not appear on the label. The RADURA-logo is optional; several countries use a graphical version that differs from the Codex-version. The suggested rules for labeling is published at CODEX-STAN – 1 (2005),[69] and includes the usage of the Radura symbol for all products that contain irradiated foods. The Radura symbol is not a designator of quality. The amount of pathogens remaining is based upon dose and the original content and the dose applied can vary on a product by product basis.

text: The European Union follows the Codex's provision to label irradiated ingredients down to the last molecule of irradiated food. The European Community does not provide for the use of the Radura logo and relies exclusively on labeling by the appropriate phrases in the respective languages of the Member States. The European Union enforces its irradiation labeling laws by requiring its member countries to perform tests on a cross section of food items in the market-place and to report to the European Commission. The results are published annually in the OJ of the European Communities.[70]

text: The US defines irradiated foods as foods in which the irradiation causes a material change in the food, or a material change in the consequences that may result from the use of the food. Therefore, food that is processed as an ingredient by a restaurant or food processor is exempt from the labeling requirement in the US. This definition is not consistent with the Codex Alimentarius. All irradiated foods must bear a slightly modified[69] Radura symbol at the point of sale and use the term "irradiated" or a derivative there of, in conjunction with explicit language describing the change in the food or its conditions of use.[71]

text: Food safety[edit]

text: In 2003, the Codex Alimentarius removed any upper dose limit for food irradiation as well as clearances for specific foods, declaring that all are safe to irradiate. Countries such as Pakistan and Brazil have adopted the Codex without any reservation or restriction. Other countries, including New Zealand, Australia, Thailand, India, and Mexico, have permitted the irradiation of fresh fruits for fruit fly quarantine purposes, amongst others.[citation needed]

text: Standards that describe calibration and operation for radiation dosimetry, as well as procedures to relate the measured dose to the effects achieved and to report and document such results, are maintained by the American Society for Testing and Materials (ASTM international) and are also available as ISO/ASTM standards.[72]

text: All of the rules involved in processing food are applied to all foods before they are irradiated.

text: United States[edit]

text: In the United States, each new food is approved separately with a guideline specifying a maximum dosage; in case of quarantine applications the minimum dose is regulated. Packaging materials containing the food processed by irradiation must also undergo approval. Food irradiation in the United States is primarily regulated by the FDA[73] since it is considered a food additive. The United States Department of Agriculture (USDA) amends these rules for use with meat, poultry, and fresh fruit.[74]

text: The United States Department of Agriculture (USDA) has approved the use of low-level irradiation as an alternative treatment to pesticides for fruits and vegetables that are considered hosts to a number of insect pests, including fruit flies and seed weevils. Under bilateral agreements that allows less-developed countries to earn income through food exports agreements are made to allow them to irradiate fruits and vegetables at low doses to kill insects, so that the food can avoid quarantine.

text: The U.S. Food and Drug Administration (FDA) and the USDA have approved irradiation of the following foods and purposes:

text:
Packaged refrigerated or frozen red meat[75] — to control pathogens (E. Coli O157:H7 and Salmonella), and to extend shelf life.[76]
Packaged poultry — control pathogens (Salmonella and Camplylobacter).[76]
Fresh fruits, vegetables and grains — to control insects and inhibit growth, ripening and sprouting.[76]
Pork — to control trichinosis.[76]
Herbs, spices and vegetable seasonings[77] — to control insects and microorganisms.[76]
Dry or dehydrated enzyme preparations — to control insects and microorganisms.[76]
White potatoes — to inhibit sprout development.[76]
Wheat and wheat flour — to control insects.[76]
Loose or bagged fresh iceberg lettuce and spinach[78]

text: European Union[edit]

text: European law dictates that all member countries must allow the sale of irradiated dried aromatic herbs, spices and vegetable seasonings.[79] However, these Directives allow Member States to maintain previous clearances food categories the EC's Scientific Committee on Food (SCF) had previously approved (the approval body is now the European Food Safety Authority). Presently, Belgium, Czech Republic, France, Italy, Netherlands, Poland, and the United Kingdom allow the sale of many different types of irradiated foods.[80] Before individual items in an approved class can be added to the approved list, studies into the toxicology of each of such food and for each of the proposed dose ranges are requested. It also states that irradiation shall not be used "as a substitute for hygiene or health practices or good manufacturing or agricultural practice". These Directives only control food irradiation for food retail and their conditions and controls are not applicable to the irradiation of food for patients requiring sterile diets.

text: Because of the Single Market of the EC any food, even if irradiated, must be allowed to be marketed in any other Member State even if a general ban of food irradiation prevails, under the condition that the food has been irradiated legally in the state of origin. Furthermore, imports into the EC are possible from third countries if the irradiation facility had been inspected and approved by the EC and the treatment is legal within the EC or some Member state.[81][82][83][84][85]

text: Australia[edit]

text: Australia banned irradiated cat food after a national scare where cats suffered from paralyzation after eating a specific brand of highly irradiated catfood for an extended period of time. The suspected culprit was malnutrition from consuming food depleted of Vitamin A by the irradiation process.[86][87] The incident was linked only to a single batch of one brand's product and no illness was linked to any of that brand's other irradiated batches of the same product or to any other brand of irradiated cat food. This, along with incomplete evidence indicating that the cat food was not sufficiently depleted of Vitamin A[88] makes irradiation a less likely cause.[89] Further research has been able to experimentally induce the paralyzation of cats by via Vitamin A deficiency by feeding highly irradiated food.[44] For more details see the Long term impacts section.

text: Nuclear safety and security[edit]

text: Interlocks and safeguards are mandated to minimize this risk. There have been radiation-related accidents, deaths, and injury at such facilities, many of them caused by operators overriding the safety related interlocks.[90] In a radiation processing facility, radiation specific concerns are supervised by special authorities, while "Ordinary" occupational safety regulations are handled much like other businesses.

text: The safety of irradiation facilities is regulated by the United Nations International Atomic Energy Agency and monitored by the different national Nuclear Regulatory Commissions. The regulators enforce a safety culture that mandates that all incidents that occur are documented and thoroughly analyzed to determine the cause and improvement potential. Such incidents are studied by personnel at multiple facilities, and improvements are mandated to retrofit existing facilities and future design.

text: In the US the Nuclear Regulatory Commission (NRC) regulates the safety of the processing facility, and the United States Department of Transportation (DOT) regulates the safe transport of the radioactive sources.

text: Irradiated food supply[edit]

text: Authorities in some countries use tests that can detect the irradiation of food items to enforce labeling standards and to bolster consumer confidence.[91][92][93] The European Union monitors the market to determine the quantity of irradiated foods, if irradiated foods are labeled as irradiated, and if the irradiation is performed at approved facilities.

text: Irradiation of fruits and vegetables to prevent the spread of pest and diseases across borders has been increasing globally. In 2010, 18446 tonnes of fruits and vegetables were irradiated in six countries for export quarantine control; the countries follow: Mexico (56.2%), United States (31.2%), Thailand (5.18%), Vietnam (4.63%), Australia (2.69%), and India (0.05%). The three types of fruits irradiated the most were guava (49.7%), sweet potato(29.3%) and sweet lime (3.27%).[94]

text: In total, 103 000 tonnes of food products were irradiated on mainland United States in 2010. The three types of foods irradiated the most were spices (77.7%), fruits and vegetables (14.6%) and meat and poultry (7.77%). 17 953 tonnes of irradiated fruits and vegetables were exported to the mainland United States.[94] Mexico, the United States' state of Hawaii, Thailand, Vietnam and India export irradiated produce to the mainland U.S.[94][95][96] Mexico, followed by the United States' state of Hawaii, is the largest exporter of irradiated produce to the mainland U.S.[94]

text: In total, 6 876 tonnes of food products were irradiated in European Union countries in 2013; mainly in four member state countries: Belgium (49.4%), the Netherlands (24.4%), Spain (12.7%) and France (10.0%). The two types of foods irradiated the most were frog legs (46%), and dried herbs and spices (25%). There has been a decrease of 14% in the total quantity of products irradiated in the EU compared to the previous year 2012 (7 972 tonnes) [97]

text: Timeline of the history of food irradiation[edit]

text:
1895 Wilhelm Conrad Röntgen discovers X-rays ("bremsstrahlung", from German for radiation produced by deceleration)
1896 Antoine Henri Becquerel discovers natural radioactivity; Minck proposes the therapeutic use[98]
1904 Samuel Prescott describes the bactericide effects Massachusetts Institute of Technology (MIT)[99]
1906 Appleby & Banks: UK patent to use radioactive isotopes to irradiate particulate food in a flowing bed[100]
1918 Gillett: U.S. Patent to use X-rays for the preservation of food[101]
1921 Schwartz describes the elimination of Trichinella from food[102]
1930 Wuest: French patent on food irradiation[103]
1943 MIT becomes active in the field of food preservation for the U.S. Army[104]
1951 U.S. Atomic Energy Commission begins to co-ordinate national research activities
1958 World first commercial food irradiation (spices) at Stuttgart, Germany[105]
1970 Establishment of the International Food Irradiation Project (IFIP), headquarters at the Federal Research Centre for Food Preservation, Karlsruhe, Germany
1980 FAO/IAEA/WHO Joint Expert Committee on Food Irradiation recommends the clearance generally up to 10 kGy "overall average dose"[6]
1981/1983 End of IFIP after reaching its goals
1983 Codex Alimentarius General Standard for Irradiated Foods: any food at a maximum "overall average dose" of 10 kGy
1984 International Consultative Group on Food Irradiation (ICGFI) becomes the successor of IFIP
1998 The European Union's Scientific Committee on Food (SCF) voted "positive" on eight categories of irradiation applications[106]
1997 FAO/IAEA/WHO Joint Study Group on High-Dose Irradiation recommends to lift any upper dose limit[7]
1999 The European Union issues Directives 1999/2/EC (framework Directive) and 1999/3/EC (implementing Directive) limiting irradiation a positive list whose sole content is one of the eight categories approved by the SFC, but allowing the individual states to give clearances for any food previously approved by the SFC.
2000 Germany leads a veto on a measure to provide a final draft for the positive list.
2003 Codex Alimentarius General Standard for Irradiated Foods: no longer any upper dose limit
2003 The SCF adopts a "revised opinion" that recommends against the cancellation of the upper dose limit.[46]
2004 ICGFI ends
2011 The successor to the SFC, European Food Safety Authority (EFSA), reexamines the SFC's list and makes further recommendations for inclusion.[107]