Trapped in a radiation suit to avoid harming others, Jennifer Takeda cannot wait to have a normal life, forsaking her days as Hazmat.
Sixteen-year-old Jennifer Takeda has everything going for her—the affluent, college-bound honor roll student and promising track and field athlete—until her deadly radioactive powers emerge, poisoning her parents, hospitalizing her boyfriend, Greg, and killing her dog from overexposure. Reactions to this incident varied: Her parents wanted to sue their employer, Roxxon Energy Corporation, believing the company exposed Jennifer to something as a child that caused her condition. After waking from a coma, Greg refuses to see her; Greg’s parents wanted her arrested; doctors wanted to study her further.
Following initial tests, Jennifer learns she’s not a mutant. Forced to wear a containment suit at all times, she comes to corrupt tycoon Norman Osborn, AKA Green Goblin’s attention; he assures Jennifer he’d teach her to control her abilities, but secretly plans to use her for his own nefarious purposes. Jennifer voluntarily joins him, but isn’t allowed to leave, and her powers are then augmented through experimentation and torture.
Following Osborn’s downfall, Jennifer and others of his experimental victims are recruited into the Avengers Academy’s inaugural class, established by founding Avenger Henry “Hank” Pym, AKA Giant-Man. He hopes to teach them to control their powers while covertly preventing them from descending into villainy, a propensity revealed by their psych profiles.
Coping with anger issues through sarcasm but still retaining an explosive temper, Hazmat endangers the other students during an early training exercise by unleashing a deadly radiation blast to defeat a robot. Learning she was chosen for the Academy because the Avengers thought she could turn evil, Hazmat wants to drop out but worries she would not be accepted elsewhere.
Hazmat produces and absorbs various lethal and non-lethal substances such as radiation, toxic waste, neurotoxins, electro-magnetic energy and on one occasion antimatter, generally releasing them from concentrated blasts from her hands.
She is also immune to these substances, but her breath, body fluids and waste are poisonous, and prolonged exposure could be fatal to others.
Before achieving control of her powers, Hazmat wears an oxygenated containment suit. Trained in unarmed combat, Hazmat is an accomplished athlete. She has beta-level Avengers security clearance and an Avengers communicator.
The one person that shows interest in Jennifer after her powers emerge is none other than megalomaniac Norman Osborn, who calls her special and offers to fix her. But his promises leave her on a table experimented upon and in a position where he could use her powers to his own ends.
Hazmat goes up against a few tough contenders like Psycho-Man, the Sinister Six, Jeremy Briggs, Sylvie Lushton, AKA Enchantress, but her most terrible foe would be Arcade. The assassin kidnaps Jennifer and her friends and places them in a death match arena in his Murder World where she suffers great loss, which leads her to seek vengeance later, only for her to slay a facsimile.
Despite her bristly attitude, Jennifer makes friends with all of Osborn’s other experimental subjects and Academy classmates, including Madeline Berry, AKA Veil, Brandon Sharpe, AKA Striker, Jeanne Foucault, AKA Finesse, Humberto Lopez, AKA Reptil, and Ken Mack, AKA Mettle. Jennifer and Ken eventually date, though she struggles with intimacy having been traumatized over putting her boyfriend Greg into a coma.
When she meets the power-absorbing Leech, she takes the opportunity to be temporarily free of her powers and later takes a cure with Mettle, but both times she ultimately chooses her powers over having a normal life.
At the Academy, Hazmat studied applied chemistry, ethics, intermediate unarmed combat, swordplay, rudiments of magic, extraterrestrial culture and other subjects. Hoping to scare the students away from crime, the Avengers took them to visit the Raft superhuman penitentiary. While there, Hazmat caused a blackout, so she and classmates Mettle and Veil could secretly confront Osborn. However, despite threatening to kill Osborn, they failed to learn how they could become normal again. Afterward, the three lied about what happened, though classmate Reptil suspected the truth.
Discovering the criminal Parker Robbins, AKA Hood, had physically assaulted and humiliated Academy instructor Greer Nelson, AKA Tigra, Hazmat, Veil and classmate Striker located and beat Robbins, then forced him to apologize on film. Their efforts earned the trio Academy probation in lieu of expulsion, and Hazmat had to attend anger management classes.
Pym introduced the power-dampening mutant Leech as an interim solution to Hazmat’s condition, enabling her to safely remove her containment suit, and visit San Francisco’s Golden Gate Park and her parents. Although thrilled to see Jennifer, they were disappointed her recovery was temporary and disturbed by Leech’s misshapen, green-skinned appearance: their reactions deeply saddened Hazmat. Subsequently, when the class visited the Stamford Memorial, where over 600 civilians died in a superhuman conflict, they were ambushed by Osborn-supporting, hero-hating Cobalt Men. Hazmat was unable to retaliate as Leech’s power-dampening effect hadn’t fully subsided. She then refused more sessions with Leech, claiming she preferred to stay battle-ready, but Pym worried Hazmat’s self-imposed isolation was a symptom of deeper psychological issues.
While pursuing his ex-wife, Carina Walters, the mad, god-like Michael Korvac, AKA Korvac, attacked Avengers Academy, and Carina desperately placed the Academy students’ minds in more powerful alternate-future bodies. In her Reality-81320 self, Hazmat temporarily knew her full potential and used an anti-matter blast to defeat Korvac. Restored to her own body, Hazmat was frustrated her adult form had still required a containment suit. Mettle consoled her, and the two soon began dating, Mettle’s metal body protecting him from radioactivity. On patrol with instructor Peter Parker, AKA Spider-Man, Hazmat was struck by Psycho-Man’s hateray but ultimately resisted its influence and destroyed Psycho-Man’s armor. The Sinister Six then tricked the students into allowing them to steal Pym’s dimensional door technology.
Later, unstable rejected Academy candidate and matter-manipulating Jeremy Briggs, now a successful businessman, implied Pym was too busy to cure Hazmat while trying to coerce the students to leave the Academy to ally with him. When Academy student Finesse revealed Briggs’ sociopathic manipulations, the students attacked. Briggs temporarily changed the oxygen in Hazmat’s suit to carbon dioxide and easily defeated the other students, but allowed them to depart aware he could kill them at any time.
Deployed to defend Washington, D.C. against Sinthea Shmidt, AKA Sin’s mechanized soldiers during the Asgardian fear god Cul, AKA Serpent’s assault on Earth, Hazmat justified potentially killing Sin’s troops to prevent innocents dying. Later, mystically enhanced by enchanted Asgardian hammers, Carl Creel, AKA Absorbing Man, and the super-strong Mary MacPherran, AKA Titania, then called Greithoth and Skirn, sought vengeance on Pym for past defeats, trapping his students inside the extradimensional Infinite Avengers Mansion by destroying Pym’s dimensional doors, which also prevented Pym from banishing them from the mansion. While trying to kill the students, Creel absorbed power from Pym’s particle generator, causing the mansion to grow, threatening to crush an entire city when it entered Earth-616 space. After the students activated the mansion’s self-destruct program, Hazmat agreed to distract the villains while her classmates escaped. However, Academy staff returned as the mansion materialized over Chicago and saved the students before it self-destructed. Greithoth and Skirn left when summoned by Cul.
Later, the decommissioned Avengers West Coast compound became the new Academy campus, its spacious accommodations allowing an expanded student body. Fearing being discarded with their arrival, Hazmat provoked her inaugural classmates to attack visiting Avengers, trying to prove the students deserved to stay. Hazmat had refrained from intimacy with Mettle, still troubled over harming former boyfriend Greg. Having killed in self-defense in Washington, D.C., Mettle fretted he might become a villainous murderer. Hazmat asked new classmate and former assassin Laura Kinney, AKA X-23 (Wolverine) to reassure him he wouldn’t. When Reptil pointed out she might have created competition for Mettle’s affections, Hazmat became jealous, but later confided in Kinney that her jealously stemmed from her own insecurities.
Later, Academy dropout Veil and former faculty member Jocasta encouraged Academy students to join the Briggs Foundation. Hazmat conceded because Briggs promised to cure Mettle, but Briggs knew she truly didn’t want to leave so allowed her to stay; his true agenda was studying Mettle’s unique Iridium shell. When a war between the Avengers and mutant X-Men escalated, Pym felt the students were in danger at the Academy and temporarily closed the school, leaving Hazmat to turn to Briggs’ Clean Slate aerosolized super-power-inhibiting nanobots, which left Hazmat and Mettle human. Enjoying being normal, Hazmat did nothing to stop Briggs’ plan to globally deploy Clean Slate to depower all superhumans until Briggs nearly murdered Striker. Choosing their friends’ lives over their own happiness, Hazmat and Mettle took the irreversible Clean Slate antidote, saved Striker and defeated Briggs. Returning to the Academy, Hazmat learned Pym was working on a cure comparable to Clean Slate but abandoned his efforts as the antidote she took immunized her to any similar cure. Hazmat appeared emotionally unaffected because she had Mettle’s affections. After completing the Academy’s freshman year, Hazmat earned beta-level security clearance and the rank of Avengers Third Grade.
On Christmas Eve, the assassin Arcade kidnapped Hazmat, Mettle, X-23, Reptil, Juston Seyfert and his Sentinel robot from campus. Arcade forced the teens and 11 other kidnapped young superhumans to fight in a 30-day Murder World arena death match against one another, starting by ordering the youths to choose the weakest among them to be killed. After Hazmat angrily attacked him, Arcade decided to make an example of her. Mettle sacrificed himself to save her, claiming he was the weakest, and was slain. The traumatized Hazmat’s temper drove Rebecca Ryker, AKA Death Locket, Chase Stein, AKA Talkback, and Nico Minoru, AKA Sister Grimm, away after they offered condolences. Hazmat and Reptil found a beachfront safe zone where Hazmat refused to participate in Arcade’s scheme, but Hazmat’s containment suit was torn open when Arcade triggered X-23’s uncontrollable feral side, leaving Hazmat injured, scared and overloading. In dinosaur form, Reptil rushed Hazmat into the ocean where she could explode without harming others. The overload somehow gave Hazmat control of her abilities, making the containment suit unnecessary. After the remaining competitors defeated Arcade and shut down Murder World, Hazmat urged the survivors to never discuss what occurred during the death match, even after Arcade publicly released video footage online.
Months later, several arena survivors tracked Arcade to Baron Helmut Zemo, AKA Baron Zemo’s underground base on the Super Villain island nation of Bagalia, where they intended to kill him. They were unaware Zemo had secretly imprisoned the real Arcade and planned to record the survivors killing an Arcade facsimile, making them fugitives so they would join his Masters of Evil. Unexpectedly re-experiencing the trauma of Murder World in the fake Arcade’s presence, Hazmat murdered the facsimile. When the Strategic Homeland Intervention Enforcement Logistics Division (S.H.I.E.L.D.) arrested the survivors, Zemo freed them, offering them Masters membership. Hazmat proposed to the survivors they accept, but only to bring Zemo’s empire down from within by covertly contacting Pym after discovering whatever Zemo had planned; the students spent three months serving Zemo, unaware he wanted them to contact their mentors. Fed false information, the survivors inadvertently led their mentors to be temporarily trapped in Bagalia while Zemo’s forces ran rampant around the globe, seizing control of the S.H.I.E.L.D. communication network and publicly revealing that S.H.I.E.L.D. was using it to monitor all global communication. Death Locket–who had not initially understood the covert mission and had truly allied with Zemo’s Masters–assumed control of S.H.I.E.L.D.’s Helicarrier for Zemo unaware arena survivor Cammi Benally hid on board. Cammi defeated Zemo and his lieutenants by turning Arcade’s technology against them, then broadcast to the world that Arcade was alive, and the survivors weren’t murderers. S.H.I.E.L.D. dropped all charges on condition the survivors would not engage in heroics without first alerting S.H.I.E.L.D. Director Maria Hill.