Barry Allen (Earth-1)

"My name is Barry Allen, and I am the fastest man alive. When I was a child I saw my mother killed by something impossible, my father went to prison for her murder, then an accident made me the impossible. To the outside world I'm an ordinary forensic scientist, but secretly I use my speed to fight crime and find others like me, and one day, I'll find who killed my mother and get justice for my father.  I am The Flash!"

- Barry Allen (Season 1 Intro)

Barry Allen (born c. 1989) is the main protagonist of the TV Series The Flash and a recurring character of Arrow. A scientific assistant in the Criminal and Forensic Science Division of Central City Police Department, Barry is the son of Henry and the late Nora Allen, the foster son of Joe West, and the best friend and foster brother of Iris West. He is also a big fan of The Arrow.

After the S.T.A.R. Labs particle accelerator exploded, it caused a giant thundercloud to form. A lightning bolt from the storm struck Barry, causing him to fall comatose. He also had unknown chemicals fall on top of him, after he was electrocuted by the lightning bolt. When he awoke, he discovered that he had developed various super powers and abilities, most notably super speed but also rapid cell regeneration. Using these super powers and abilities, he began acting as the vigilante and superhero known as The Flash.

Early life
When Barry was eleven years old, he ran home from school after getting in to a fight. Though not being fast enough, his mother promised that he had a good heart, and his father was proud of him for winning the fight. That night, he was woken by a noise from downstairs. He walked downstairs to see his mother enclosed in a tornado-like blur. As Barry watched on in horror, his father approached and held him back. His father insisted he run, and suddenly he was transported by a flash of yellow several streets down. As he ran home, his father was being arrested by police, the former who told him not to enter the house. He entered, seeing Detective West standing solemnly over a body. When he walked away, Barry approached the body and discovered, to his horror, that it was his mother. Following the ordeal, Barry was fostered by Joe West, whose daughter, Iris, Barry was best friends with.

Initially, Henry asked Joe to not let Barry see him. Not knowing this, Barry kept trying to run away to see his father at Iron Heights, and he was caught and stopped by Joe every time; at one point, Barry called him out for it, telling him that he wasn't his father and that he hated him. Eventually, Barry finally reached Iron Heights before Joe could stop him, and he finally came face to face with his father. Henry told him that he simply did not want Barry to see him in prison. Despite this, Barry begged for his father's release, insisting that the man in the lightning was who killed his mother, not Henry. Henry told him that he couldn't help him and asked that he be a good boy while Joe raised him. Henry was promptly taken away.

At the age of 12, Barry went to reptile camp, which was paid for by Joe.

After he finished school, Barry was motivated by his mother's murder to study criminology, in the hopes of proving that his father was innocent.

Visit to Starling City
Years later, Barry arrived in Starling City. He wasn't able to initially get a cab as the driver pulled away, and he soon arrived at Queen Consolidated's Applied Sciences Division to investigate a mysterious break-in as a CSI from Central City with a connecting case, where he met Oliver Queen, John Diggle, Quentin Lance and Felicity Smoak (the latter whom he had an instant connection with).

He was set up in the division with Felicity's help, unknown to Barry, because Felicity believed that they should have used him as an asset seeing as forensic science was not the expertise of any of their team (namely Felicity, who usually did most of the information gathering and recon). The two began talking, and Barry began speculating about The Arrow and his background, making incisive observations about why The Arrow wore green instead of black, the type of arrows he used, and how he theorized that The Arrow has partners, particularly someone who had a background in computer sciences; all of this unnerved Felicity.

Barry was astounded when Felicity asked him to help with a blood sample from an arrow she received from the police both by her "connections" from working for Oliver, and the fact that he was working the same case as The Arrow. During that particular part of their investigation, Felicity invited Barry to a Queen Consolidated function, which was actually a party at the Queen Mansion. However, before the results came in, his cover as a crime scene investigator working for the police was blown by Oliver just after he and Felicity began arguing over a news report about the mass particle accelerator. It was revealed that he was just an assistant CSI and there was no connecting case in Central City. Barry explained what happened to him as a child, and how it had caused him to begin looking into cases with impossible circumstances, in hopes of one day proving one possible, therefore solving his mother's murder and freeing his father. He was later re-invited by Oliver as Felicity's plus one to come to his home where he was throwing a party for his mother. When there, he apologized to Felicity while they danced.

After the party, Barry was contacted by his boss and was told to return to Central City if he hoped to keep his job, and revealed the sedative used was ketamine, informing Felicity it should have been easy to track. He tried to catch the soonest train, though missed the last one of the night. He settled down in to the train station to wait for the next one in the morning, when suddenly he was hit with a tranquilizer dart to the neck. When he awoke, he found himself in Oliver's base with Diggle watching him and Oliver lying on a table in full Arrow costume. Felicity approached him and asked Barry to save Oliver's life, who was not only poisoned with an unknown substance from the A.R.G.U.S. disaster bunker, but also had been beaten by the robber who had stolen the centrifuge from Queen Consolidated, raided the blood bank, and encountered Oliver as The Arrow while stealing large amounts of ketamine from the bunker.



Barry was able to save Oliver's life, which Oliver was not too pleased with at first, as they had revealed his secret without his permission. However, Barry eventually gained Oliver's trust. He recommended that a mask would be better than the green grease he used on his eyes as better concealment of his identity. Oliver later asked him if there were any side effects to the rat poison he injected in him, and Barry told him that it could cause hallucinations and heavy sweating. He then discovered that Oliver's hallucinations weren't from the serum, and that it was psychological. Barry soon after headed back to Central City.

After he arrived back, he soon headed back to work, arriving to a crime scene late. He was successfully able to identify the getaway car from the robbery and also grabbed a sample of some animal feces found on the ground, before heading back to his lab to examine the evidence. While processing the feces, he was greeted by Iris West. Barry discussed the S.T.A.R. Labs particle accelerator, noting that it provided ideas that were far beyond their current capabilities of science, hence why he was so excited. Detective West approached right as the feces had processed. Barry described the results found, explaining that it had a chemical used only at four different farms around town, suggesting they check them out. Following, Barry and Iris headed to the unveiling and switching on of the particle accelerator. Barry attempted to convey his attraction towards Iris, but she simply misunderstood it. They began listening to S.T.A.R. Labs CEO Harrison Wells, who described how the particle accelerator would lead to a much greater future. As they were listening, a guy stole Iris' bag along with her laptop inside it. Barry ran after him, attempting to catch up to him, however the guy knocked the wind out of him and ran off (only to later get caught by Detective Eddie Thawne). At the police station, Iris and Barry mocked Eddie, a new transfer from Keystone City. Later Barry headed to his lab, watching the news of the S.T.A.R. Labs particle accelerator, but as he watched it, it became unstable. The particle accelerator sent a shockwave through the city, and only seconds later was Barry struck by a red bolt of lightning through a window in the roof. He was sent backwards through the already-charged chemicals and was knocked unconscious. A red flash of light appeared across his cheek, rising, and then faded away. He was quickly rushed to hospital, where he was kept on life support whilst in a coma.

For the following five weeks, Felicity Smoak visited Barry in the hospital while he was in a coma, and left only to help Oliver. Barry's heart constantly seemed to stop working, however it was concluded by Harrison Wells, who begun to visit him, that his heart was in fact beating too fast to even register. When Barry's condition began to worsen he was moved to S.T.A.R. Labs to be closely monitored and was frequently visited by Iris West.

Becoming The Flash
When he awoke from his coma 9 months later, Barry met Cisco Ramon, Harrison Wells and Caitlin Snow. He learned of his coma and how it had been caused by the explosion of the particle accelerator. Much to their annoyance, Barry chose to leave, claiming that he felt normal. Barry went to meet Iris at her work, where the two embraced, Iris incredibly thrilled to see Barry awake and walking. As they talked, Barry noticed time slow down, then fasten back up again. Iris grabbed her jacket, then they went to visit Joe at the police department. Joe was more than happy to see Barry, though he was called to a robbery at Gold City Bank. Detective Thawne followed West, also expressing his happiness at Barry's return. As they left, Barry noticed a rough detainee, who quickly reached for a police officer's gun. Before he could grab it, Barry sped over to him and back, stopping him from doing anything. Freaked out by the incident, Barry promised to call Iris that night and left. Once outside, Barry noticed his hand shaking at an unbelievable speed, shortly followed by him accidentally almost running in to a bin at super speed, then breaking the back window of a cop car. Realizing the gifts he had, Barry went off running, testing out his super speed. Before long, he accidentally ran through the back of a van. Sometime later at an airfield, Barry met with Cisco, Caitlin and Wells. He put on a tight suit and got ready to run. Dr. Wells cautioned restraint, whereupon Barry began to run at full pelt. Partway through, he began to remember the night of his mother's murder, specifically a ball of lightning with a man seemingly inside it surrounding his mother, and he crashed, fracturing his wrist. Back at S.T.A.R. Labs, they discovered that Barry's wrist had healed in under three hours, much to their amazement. Dr. Wells inquired as to what happened, and Barry explained what he'd remembered: a man somehow inside a ball of lightning. Barry raised the question that perhaps there were more people like him, but Harrison rejected the idea, claiming that Barry was unequivocally one of a kind. Following that, Barry went to meet Iris at Jitters. He looked upon Iris and Eddie kissing, and they soon took a walk as Iris explained to Barry how the two of them had met, asking him to promise not to tell her father. As they talked, a police car involved in a car chase slammed on the brakes, leading to Barry pulling Iris out of the way as the car hit the wall under the bridge. As the other car raced by, Barry recognized its driver: the seemingly dead Clyde Mardon. Barry ran after the car, crashing through the side and entering. Before Mardon could get his gun out, Barry grabbed the steering wheel, making the car tumble on its side, on to its top. Mardon exited the vehicle, relatively unscathed and Barry quickly followed. He called out to catch Mardon's attention, but soon the area was flooded with fog, apparently made by Mardon himself, causing a car to run in to the already overturned car, forcing Barry to speed to a nearby patch of grass for safety. Paramedics soon arrived, along with the police, including Joe. Joe scolded Barry for having Iris out in the open and Iris for having followed the danger. Barry took Joe aside, telling him of his belief that the car was driven by Clyde Mardon, who had apparently survived a plane explosion, also somehow gaining the ability to control the weather. Despite various pieces of apparent evidence, Joe didn't believe him. Frustrated with Barry's seeming fantasies, Joe explained how his claims were impossible, including the ball of lightning with the man inside; he knew Barry's father was the murderer, as did numerous others. Having never asked for anything from Barry, Joe asked Barry to for once be realistic, to which Barry simply walked off, disappointed. He returned to S.T.A.R. Labs, angry at Wells for lying to him about being the only one affected by the particle accelerator's explosion. Dr. Wells claimed to not be entirely sure, as there had been numerous amounts of radiation including anti-matter, dark energy and x-elements, all apparently theoretical prior to the event. Despite their apparent theoreticalness, Wells claimed that Barry was proof otherwise. He went in to more detail, explaining that they'd been looking for more "metahumans", a term they'd coined for people like Barry. Barry brought up Clyde Mardon, whom they had to stop before he hurt anyone again. Wells cautioned Barry to keep himself safe, as Barry had the potential to unlock previously undiscovered vaccines, medicines and breakthroughs in science, yet he wished to put himself on the line and "play hero". Dr. Wells saw him as nothing special, just a boy who'd been struck by lightning. Upset by Harrison's statement, Barry called Oliver Queen, hoping to get some advice. He visited Oliver in Starling City, where he expressed that he believed Barry could save people, though in an entirely different way to The Arrow. As opposed to The Arrow's tough vigilantism, Barry could be a guardian angel to the people of his city, saving them "in a flash". As he speeds away, Oliver expressed his awe at Barry's powers. Barry headed back to Central City, to S.T.A.R. Labs. He apologized to Caitlin and Cisco, understanding that they'd lost things in the explosion, but there had been an increase in crime, presumed to have led from the creation of metahumans. They agreed to help, and Cisco even suggested the use of a suit he'd made, initially for a firefighter, but believed it suited Barry well. He put on the suit and raced to Mardon's farm, where they'd noticed an acute change in the weather. He saved Joe and Eddie, who'd come to investigate, after a piece of debris flew at them. With Mardon's tornado heading towards the city, with an increasing wind speed, Barry suggested that he run around the tornado in reverse in order to unravel it. Despite Caitlin and Cisco's belief that Barry might not hold up, he proceeded to run around it. Before he could run fast enough, Mardon knocked him away. Believing him to be too strong, Barry didn't think he could beat Clyde. However, as he was about to give up, Dr. Wells began communicating with him. Despite acting selfishly, Wells expressed that he truly, deeply believed that Barry was special, that he could help stop the havoc he'd created. With the confidence boost, Barry was able to run fast enough, clocking just over 700mph, ultimately unraveling the tornado. After being knocked to the ground, both Clyde and Barry stood up. Clyde proceeded to point a gun at him, claiming them to be the same, though Barry strongly disagreed. Before he could shoot Barry, Joe intervened. The following morning, still at the crime scene, Joe and Barry discussed Barry's powers and Joe apologized, for not believing him and for also believing his father a murderer. Barry also promised not to reveal anything to Iris so as to keep her safe. Not long after, Barry visited his father in Iron Heights Prison, assuring him that he still believed in him, that he was incredibly proud to be his son. After that, with a lightning bolt symbol added to his suit, Barry ran through the streets of Central City, saving a man from crashing on his bicycle.

Sometime after, Barry was at work when he overheard a call that Joe and Eddie received of a situation at the Central City National Bank. He left and suited up, making his way to the bank, not before saving some dogs on the way. He attacked the man, finding that his punches didn't do much. The strongman threw him in to a pillar, causing it to break. Barry used his super speed to escape the crash and left before Joe or Eddie could see him. He made his way back to S.T.A.R. Labs, by which time his ankle had healed the wrong way. He informed the team of it and they sought to re-break it and set it straight. Barry described the strongman to Dr. Wells, who insisted that Barry not take it to the police, as he had to keep his secret identity a secret. He received a text requesting his presence at the crime scene. When he arrived he encountered Iris. She and Eddie walked off together, so Barry got to work by collecting DNA samples of the man. He overheard Eddie talking to another cop, believing that not only were he and Iris like siblings, but that Barry wasn't even her type. Barry handed over the DNA samples to Caitlin and Cisco, and went to help Joe get fingerprint samples from a man who was at the bank. Barry took the man's fingerprints, but accidentally hurt him when he was paying too much attention to Iris and Eddie. Following that, Joe and Barry left. In the car, Barry expressed his disappointment at having to keep his secret hidden, but Joe simply reassured him that it was necessary. As they talked, Eddie and Iris were involved in a crash in front of them. Barry and Joe got out of their car to help. The other two were fine, but they were all quickly shocked by the cause of the crash; a number of leopards and a tiger, who leapt towards Iris. As Eddie attempted to keep the cats at bay, Barry evacuated a bus using his super speed, then used some static electricity from the bus to scare the cats away. Unbeknownst to him, Eddie was left to think that he had done it, while Barry left the scene. He contacted Cisco and Caitlin, who alerted him to a group of chimpanzees wrecking a Tech Village store nearby. He suited up again and headed over there, giving each of them fruit from a fruit stand and allowing them to watch King Kong on a TV. Soon after, he directed them back towards the zoo. On the way there, an eagle defecated on his face. After locking the chimpanzee enclosure, Barry noticed a collar with a purple top hat on the tag, which he recognized. Caitlin and Cisco revealed that they'd ID'ed the sweat sample, finding that it belonged to Joey Rose. Cisco suggested he get back before anyone notice he was gone. When he arrived back in the tunnel, back to his usual clothes, Eddie noticed the smell of poo on Barry. Given that Barry had claimed he'd been hiding, they inferred the worst, Joe suggesting they head back to the police department and get cleaned up quickly. As he was about to exit the police department, Captain Singh ordered Barry, Joe and Eddie to check out a homicide at 122 West Olympic Street. Whilst there, Barry noted bite marks on the victim from a Russell viper. Eddie noticed papers strewn around the floor were in fact deeds to businesses; among them in particular was a circus. Barry contacted Caitlin, who unearthed that the circus, Central City Circus, was foreclosed, with the owner having previously escaped from Belle Reve, killing two people.

Barry continued to save citizens throughout Central City, much to the frustration of Caitlin and Joe. At his day job with the CCPD, Barry investigated a strange robbery and murder scene wherein the surveillance footage showed one man, but evidence indicated that there were at least six present. He later made a casual remark that the perp's footprints were about the same size as those of Captain Singh's but was reprimanded for it by Joe, who reminded him not to tell Iris about his ability. Later, Barry went to Stagg Industries with Iris, where Simon Stagg was set to receive an award from Central City University. Iris was covering the event for her journalism assignment and needed Barry to help her with the scientific parts. At the event, the armed gunmen responsible for the scene Barry had just investigated came arrived and was in the process of taking their valuables when a security guard attempted to stop them. Just before they could shoot him, Barry saved him and went after the robbers, only to lose consciousness along the way. After his fainting, this prompted the S.T.A.R. Labs scientists to investigate Barry's recent weaknesses. After a run at a "Cisco'd" treadmill, it was discovered that Barry had acute hypoglycemia, a condition that Barry developed because of his sped-up metabolism and could be remedied by a more extensive meal plan. Joe then arrived at the lab and called him out for his unnecessary heroics. Because of this, Barry lost confidence in himself and, face to face with Danton Black, the metahuman that infiltrated the Stagg event, he realized that he did not have the ability to really go up against them. At this point, Iris was still trying to get Barry to tell her what was going on with him. Just when he had momentarily quit his association with Wells and the others, Iris revealed that her new journalism topic would be his alter-ego, who has been dubbed the "red streak" by citizens. Caitlin then called Barry back to S.T.A.R. Labs and told him of a way to defeat Black. Joe then arrived to convince Barry to go after him. Barry did and followed Danton to Stagg Industries, where he intended to kill Stagg once and for all. With pep talk from those at the Lab, including Joe, Barry was able to isolate the real Danton from the hundreds of clones and put him down. When Danton momentarily regained consciousness, he attacked Barry only to miss and hit the window. Barry tried to save him from falling but Danton, not wanting to be saved, summoned up an extra hand to pull him from Barry's grip and fell, much to Barry's disappointment. Later, Barry commended the group at the lab, who then fully supported Barry's city-saving, even Caitlin, and made amends with Joe.

Barry went to the movies with Iris when Cisco and Caitlin  informed him of a car chase. Using his speed Barry quickly stopped the robbers and returned before Iris knew he was gone. the next day Barry and Joe investigated the death of the Darbinyan crime family. Noting that while the victims were poisoned with gas and that they all had chances to increase they're survival they all died at the exact same time. with Barry realizing that they were dealing with another meta human who could control gas. At Star Labs Joe discussed that they must find a way to contain the meta-humans they capture. Wells and Cisco decided that the Particle Accelerator would be the best place to hold them until they could cure them of their powers. Caitlin remembering the death of her fiancee Ronnie Raymond froze seeing her distraught Barry decided asked if Caitlin could him identify the meta-human. At Barry's Lab the two talked about Ronnie until the DNA results came back revealing that the Gas inside the victims had someone else s DNA.. Hearing the murder of Judge Theresa Howard on the police radio Barry left despite Caitlin pleads. Arriving at the scene Barry found himself to late and angriliy chased after the meta-human who ended poising Barry. Rushing back to Star Labs the team just barley managed to save him. Despite being told to rest Barry went to talk to Joe and confide in him about his inability to save the Judge and his temptation to break his father out of jail however Joe tells Barry that despite his powers he cannot save everybody and that breaking his father out of jail would just make things worse for him. Later Barry apologized to Caitlin for worry her only for Caitlin to reveal that what he said to her were the same last words Ronnie said before he died. Barry decided to help her overcome her fear of walking into the Particle Accelerator. After finding peace she thanked Barry and the two embraced. Well's and Cisco soon called them up and revealed that a sedative was also found in the gas. Barry told Cisco to check if anyone was executed on the night of the Particle Accelerator. The results coming back with Kyle Nimbus a hit men who was a hit man for the Darbinyan crime family who turned on him leading him to be arrested by Joe West and prosecuted by Judge Theresa Howard. Barry quickly suited and headed to Iron Heights prison saving Joe who was visiting Barry's father. Barry then went after Nimbus defeating him by keeping him in his gas form causing him to revert to human form to catch his breath allowing Barry to knock him out. Barry Later visited his father and confided in him they he missed his mother. Henry comforted him telling him as child he ran to his mother with Barry realizing that to honor his mother he must keep running.

Personality
Barry is described as someone who complements Felicity Smoak's intellect level, both when it comes to forensics, as she claims it's not her strong suit, and science in general. He is also someone who is regularly late as he missed a train, boarded a late train, and misses a cab all to get to Queen Consolidated's warehouse, and missed the last train back to Central City. He is also considered a comic geek.

Much like Oliver, he has a strong sense of justice, due to the fact he knows his father is innocent of a crime he was convicted of, and for which he is still serving a life sentence. He joins the forensics department to both learn how to investigate crimes, and study cases with unexplained elements, to prove his personal account of his mother's murder true, and ultimately, free his father. Barry is very intelligent, like Felicity he is socially awkward, and sometimes gets nervous and babbles.

Barry has good morals, he does not like to lie about who he really is, like when he first met, Oliver, Felicity and Quentin, and told them he was a forensic scientist, this was only because he knew they wouldn't take him very seriously if they knew he was only an assistant forensic scientist, when Oliver confronted him, after he found out who Barry really was, He did not try to deny it, but he also explained the reason why he did it.

Barry has a lot of respect for the vigilante known as The Arrow, when he found out that Oliver/The Arrow are the same person he was amazed, he also saved his life after he was injured by Cyrus Gold and consequently poisoned, despite the fact that he barely knew Oliver, he also keeps his secret, despite his respect for Oliver, Barry is not above standing up to him, like when he pointed out that Oliver was being a jerk to Felicity, but he said this in a respectable way.

Powers and Abilities

 * Superhuman speed: After being electrocuted by the lightning storm created by the S.T.A.R. Labs particle accelerator and having unknown chemicals falling on top of him, Barry gained superhuman speed. It allows him to move much faster than a normal human. Noticeably, his physique has also been augmented, obtaining a lean-built frame to better handle these increased speeds. He has shown to be able to move at speeds over 700mph.
 * Superhuman leaping: When Barry builds enough momentum he can project himself high into the air, as seen when he jumped 10-15 feet in the air, to collide with a piece of debris to save Joe West.
 * Superhuman stamina: Barry's body can handle the stresses of superhuman racing without noticeable distress and his body's enhanced stamina allows him to function much longer then a human, without getting tied or weak.
 * Superhuman reflexes: Barry's increased speed also augmented his reaction time, allows him to react to danger and events react much faster than a normal human.
 * Accelerated perception: Barry speed also extends to his senses and mental capacities, allowing him to take in information and process it at much faster rates than a normal human. This ability allows Barry to see the world as if it is in slow motion, which combined with his physical speed lets him perform thoughts and actions long before a normal human around him could even perceive.
 * Rapid cellular regeneration: Another affect to his augmented speed is dramatically heightened healing capacities. In the event he is injured, his body undergoes rapid cell regeneration, allowing him to heal much faster than a normal human. After breaking his wrist while testing his newfound speed, Barry made a full recover within 3 hours, with no lingering effects of signs of it ever happening. His body is also has a heightened resistance, if not immunity, to any drugs, and toxins, and poisons.
 * Superhuman force generation: Through generation of momentum via his extreme acceleration, he is able to propel himself through the air and create substantial frictional force with any object he comes into contact with, which manifests in a powerful strike, often propelling said object several feet.

Skills

 * High-level intellect: Barry is very intelligent, as proven by his many accurate theories about The Arrow. He correctly determined The Arrow's training background from his green attire, and that The Arrow has one or more accomplices, including one with a background in computer sciences. Barry is well-informed of the Arrow's many foes, showing great information gathering skills. He was also able to cure Oliver Queen after he was injured by Cyrus Gold and consequently poisoned.
 * Forensic expert: Despite just being a forensic science assistant, Barry is a highly skilled examiner. From a single glance of the crime scene, he can quickly determine much of the events that transpired.
 * Chemistry expert: Barry's knowledge and skill in chemistry is very advanced, shown when he was terrified that nitric acid was next to hydrazine, and permanganates on top of acetone, describing all 4 chemicals as the definition of dangerous. Also shown when he used unknown types of chemicals to make a compressible micro-fabric green domino mask for Oliver, so he can conceal his identity more effectively than the grease paint Oliver was previously using.

Weaknesses

 * Hypermetabolism: While moving at accelerated speeds, Barry burns calories much faster than a normal person. This requires him to consume large amounts of nutrients to maintain his peak physical performance. Continued usage of his speed while deprived of such render him disoriented and weak before ultimately passing out. Also, because of his accelerated healing, he is unable to receive relief from pain and such by medicine as he will burn through it too quickly to produce any effect.
 * Over-exertion: It is possible that his body cannot physically handle exerting too much of his power, and can kill him before his healing can take affect.


 * Cold temperatures: Because speed comes from a build of body heat, Barry is vulnerable to extreme cold temperatures. Under these conditions, Barry's speed will be greatly reduced. It will also stunt his healing capacities.

Equipment

 * The Flash costume: Barry wears a costume as his superhero alter-ego, The Flash, to hide his identity from his enemies, when he goes out fighting crime. The costume is made out of a reinforced tri-polymer and is heat and abrasive resistant, it was designed by S.T.A.R. Labs. Barry's mask has the ability to conceal his identity very effectively, it has no restrictions on his visual field while he is running.

The Flash: Season Zero

 * "The Strongman Cometh"
 * "Who Let the Chimps Out?"
 * "A Goodnight Hiss"

Trivia

 * He tends to be late for everything, a homage to the fact that in the DC comics Barry would be late for everything to keep his identity as The Flash a secret, though in the Arrow universe it's just because he is unlucky.
 * The original DC comic book version of Barry Allen has blonde hair whereas the Barry Allen in Arrow has dark brown hair.
 * In the DC comics, Barry's mother was murdered by Eobard Thawne, better known as Professor Zoom or the Reverse-Flash. The tornado-like blur that killed Barry's mother in Arrow seems to be a reference to this.
 * In the DC multiverse Barry Allen is the second person to take up the superhero mantle of The Flash, after Jay Garrick.
 * Just like his DC comic book version, Barry has a hyper-accelerated metabolism and must regularly take in a very high caloric intake to avoid losing energy and passing out. To remedy this, Cisco Ramon created a very calorie-dense series of protein bars for Barry to eat in order to avoid hypoglycemia.

Behind the scenes

 * In 2014, The Flash is the third DC-owned character to have its own television broadcasted show on The CW, following Smallville and Arrow.