Michigan State University in East Lansing, Michigan, scrambled to relocate some final exams after police said they discovered a man inside Wells Hall with household substances that could be used to make methamphetamine, according to a campus police chief and court filings. Wells Hall, described as the university’s largest academic building, was closed after a Sunday-night trespassing call led officers to the man inside.

Police charged the 31-year-old man on Wednesday with malicious destruction of property and possessing substances to operate a meth lab, campus authorities said. Yankowski, the campus police chief, did not explicitly say investigators found an active drug operation inside the building, but a court filing described substances that “destroyed approximately $20,000 or more of Wells Halls, specifically multiple doors and flooring.”

In a statement about the items officers said they encountered, Yankowski said the materials included hydrochloric acid, methanol, isopropyl alcohol, acetone and butane. He said many of the substances were “household items,” and he warned that while the individual products might not be dangerous on their own, “if you start mixing chemicals together there is a reaction.”

Yankowski said police responded to a trespassing call and found the man Sunday night with multiple bags of liquids that turned out to include the chemical substances listed in the chief’s remarks. The police affidavit referenced in the case says the man had his expired student ID card, and he was ordered to jail on $500,000 cash bond, the reporting said.

The chief declined to say whether the man is a student, focusing instead on the police materials found in the building. Michigan State was holding final exams this week and was also preparing for graduation events, which university officials adjusted after the closure of Wells Hall.