Categorized primarily as alternative metal and nu metal, the album features elements of multiple genres, including folk, progressive rock, jazz, and Armenian and Greek music, including prominent use of instruments like the sitar, banjo, keyboards, and piano.

It contains a wide array of political and non-political themes, such as mass incarceration, the CIA, the environment, police brutality, drug addiction, scientific reductionism, and groupies.

It was certified sextuple platinum by the Recording Industry Association of America (RIAA) in July 2022, signifying at least six million copies sold in the United States.

[3] "Going into it, I knew Serj wanted to sing more, so I guess that was a kind of a progression and an evolution for the band.

I wanted to do all that, yet not lose the heaviness of the band and I guess the hard, punk, metal aspect.

[4] Guitarist Daron Malakian said that he "wanted to add a bit more harmony for" himself "in the songs and that required tastefully mixing in some softer guitars between the really heavy parts".

[22] Serj Tankian said: "It's about the unfairness of mandatory minimum sentences and how there are about 2,000,000 Americans in jail, and a lot of them are in there for marijuana possession and things of that sort.

"[24] Tankian said that "Prison Song" also addresses "how drug money is used to rig elections in other countries by the CIA".

[8][24] "ATWA" (an acronym for "Air, Trees, Water, Animals") is about Charles Manson's beliefs on the environment.

[26][27] On September 3, 2001, System of a Down had planned on launching Toxicity at a free concert in Hollywood, California as a "thank you" to fans.

The concert, which was to be held in a parking lot, was set up to accommodate 3,500 people; however, an estimated 7,000 to 10,000 fans showed up.

Because of the large excess number of fans, the performance was cancelled by police officers just before System of a Down took the stage.

Fans waited for more than an hour for the band to appear, but when a banner hanging at the back of the stage that read "System of a Down" was removed by security, the audience rushed the stage, destroying all the band's touring gear (approximately $30,000 worth of equipment) and began to riot, throwing rocks at police, breaking windows, and knocking over portable toilets.

The band's manager, David "Beno" Benveniste, later said that the riot could have been avoided if System of a Down had been permitted to perform or had they been allowed to make a statement at the concert regarding the cancellation.

During their concert at Grand Rapids, Michigan's Van Andel Arena in October 2001, Odadjian was harassed, racially profiled and physically beaten by some guards when he attempted to enter backstage.

[34] Q wrote that Toxicity "matches Slipknot for manic intensity while employing a freeform approach to songcraft which invites comparison to the lunatic-fringe rock of the '60s".

[37] Referring to Toxicity as "both manic and schizoid", Keith Harris of Rolling Stone noted Tankian's ability to veer "easily from sing-rap rhythm to Korn-ish hysterics to demonic baritone growl to doomily ruminative" and that "the music insists on forward motion without trapping itself in a thrashy lock-step rut".

[38] Tom Sinclair of Entertainment Weekly called the album "strange and engaging", with a wide variety of sounds which "all adds up to bizarro type of metal that has a warped majesty and strength".

[15] Robert Christgau of The Village Voice cited "Prison Song" and "Bounce" as highlights and later assigned the album a one-star honorable rating.

[48] On July 19, 2022, the album was certified sextuple platinum by the Recording Industry Association of America.

[57] Toxicity was voted the 27th best album of the year in The Village Voice's annual Pazz & Jop critics poll for 2001.

[76] All lyrics are written by Serj Tankian,; all music is composed by Daron Malakian,Adapted from Toxicity's liner notes.