Tar is a drug that when ingested, grants increased size and muscle mass, granting enhanced strength and durability to users. Though temporary, the effects have allowed users, dubbed Tar-Freaks, to trade blows with Steel and withstand direct fire from conventional arms and Toastmasters. The drug also induces increased anger and is addictive if used too much.
In addition to regular Tar, and enhanced version known as Super-Tar - usually shortened to "S-Tar" - was created. This version provides the same enhancements as regular Tar, but makes users bigger and stronger than normal users. Also, S-Tar has two trade offs for making users stronger. The first flaw is that induces a brief but powerful high that quickly deteriorates, leaving users in an uncontrollable rage. The second is that after enough doses, S-Tar will cause massive internal hemorrhaging, killing users almost instantly. Combined with its addictiveness, S-Tar is almost guaranteed to kill a user, especially if used more than once.
A special case among Tar users is Natasha Irons. When she uses the substance, the size increase in minimal. Unlike other users, who grow several times their size, Natasha only grow to be about the size of a physically fit adult woman. Also, she remains in complete control of her emotions. It is only the last time that she is affected by Tar that her form and personality change to that of a normal Tar-Freak.
When John Henry Irons moved back in with his family in Washington D.C., he first witnesses the use of Tar when he gets caught in a skirmish between two rival gangs. To counter the Central Avenue Sharks using Toastmasters, the East Streeters use Tar to level the playing field. John tried to fight off a Tar-Freak, but is knocked out. As he began his crusade againts the use of Tar and Toasmaster as Steel, he encountered many Tar-Freaks, but he manages to defeat them, or hold them off until the effects wear off. His nephew Jehmal, being in a gang, used S-Tar to attack his leader when he discovers that he was using the gang to target his family. He manages to best his leader, but Steel stops him from finishing the fight. Once Steel takes down Amertek, the gangs use of Tar is no longer mentioned.
However, John's nephew Jehmal hid a small stash of Tar for emergencies. When Steel is caught in an intense battle with the team Black Ops, he tries to take a vial, but Natasha Irons shows up, and takes the tar before he can. She uses the effects to help Steel defeat black Ops. Later, when Steel is attacked by a demonic looking version of his armor, Natasha takes tar again to help. While that was the last time she used the substance, the effects on her lingered. After the death of her grandmother, Natasha spends time at her grave. When John flies in to talk to her, she grows in size and attacks him in a fit of rage. John manages to restrain her until the Tar is fully burned out of her system. Later, blind gravekeeper who communicates with the dead tells her that Bess waned her to stop using Tar, she promises to stay off the substance. After the two leave D.C., no one is seen using Tar again.