Biohazard PhotoBiohazard was one of the first bands to regularly incorporate elements of both hip-hop and hardcore metal into their sound; since their lyrical fare dealt with the harshness of urban life and the resulting anger and frustration, which both genres of music have been known to address, the connection only made sense, especially in light of Anthrax's highly effective collaboration with Public Enemy on 1991's "Bring the Noise." When Biohazard formed in 1988 in Brooklyn, NY, their sound was much closer to the former band than the latter; their original lineup consisted of guitarist/vocalist Billy Graziadei, bassist/vocalist Evan Seinfeld, guitarist Bobby Hambel, and drummer Danny Schuler. They began opening for local hardcore and thrash bands and gradually built a large following through their outraged sense of injustice, political awareness, and constant touring. A self-titled debut was released in 1990 on the Maze label, but by 1992, Biohazard's fan base was strong enough to secure a deal with Roadrunner Records.

Their subsequent breakthrough album, Urban Discipline, built on the groundwork laid by "Bring the Noise," laying rhythmically shouted vocals over heavy, hip-hop-influenced beats and guitar riffs recalling both hardcore and thrash. The hardcore rap group Onyx recorded an alternate version of their hit single "Slam" with Biohazard backing them, and the two groups worked together again on the Judgment Night soundtrack, contributing the title song. 1994's State of the World Address solidified both their reputation for intensity and their musical hybrid, but Hambel then left the band, reducing them to a trio for 1996's Mata Leao, which some found the group's most seamless rap/metal fusion yet. Hambel was eventually replaced by ex-Helmet guitarist Rob Echevarria, and in 1997, Biohazard released the live album No Holds Barred, which showcased the in-concert ferocity for which the group had become revered. In 1999, Biohazard released New World Disorder. ~ Steve Huey, All Music Guide