Massachusetts prosecutors will dismiss more than 6,000 convictions tied to a former chemist who authorities say was high almost every day for eight years while she worked at a state drug lab.

The American Civil Liberties Union of Massachusetts and the state's public defender agency said Thursday that several district attorneys have notified them of their plans to dismiss cases that relied on evidence tested by Sonja Farak. Several other prosecutors haven't yet said how many cases they intend to toss.

Farak pleaded guilty in 2014 to stealing cocaine from the state crime lab at the University of Massachusetts Amherst and was sentenced to 18 months behind bars.

Farak's case is separate from another Massachusetts drug lab scandal that resulted in the dismissal of some 21,000 convictions this year.