Two chemistry professors in Arkansas are accused of making methamphetamine in a lab at their school.

According to a statement from the Clark county sheriff, Jason Watson, Terry David Bateman and Bradley Allen Rowland, of Henderson State University, were arrested and charged with manufacturing meth and use of drug paraphernalia.

The center was closed for three weeks. It reopened after a test confirmed it met Environmental Protection Agency standards regarding air quality. The college spokeswoman said an investigation was ongoing.

The charges facing the professors carry sentences of up to 40 years, for making meth, and up to 20 years for use of drug paraphernalia.