A 28-year-old Puna woman, arrested after an explosion at a butane honey oil lab in Puna, has been released from police custody.

Butane honey oil, also known as hash oil, is a byproduct of marijuana, and sometimes used in e-cigarettes.

Hawaii County police arrested the Keaau woman Monday on suspicion of drug charges, but was released noon Tuesday pending further investigation.

The 30-year-old Keaau man who was injured in the explosion Saturday  at a Hawaiian Paradise Park subdivision home remains in critical condition at Straub Medical Center with second-degree burns, police said.

The powerful blast blew out windows, melted plumbing fixtures and knocked doors off cabinets, police said.

Police vice Lt. Mark Farias said in a written news release that butane honey oil labs are becoming more prevalent on Hawaii Island, and warns they are “extremely volatile and can have tragic consequences for knowing participants and as well as innocent victims.”

Anyone with information about any such labs are asked to call Hawaii County police at 935-3311 or CrimeStoppers at 961-8300 in Hilo or 329-8181 in Kona.