I used petro based chemcials in my parts washer for decades, but now use water based chemicals and have for a couple of years now, which are safer for may reason, no flammable threat, and they can't asorb into skin as easily as petro based, checmial, sure you wear gloves, but let'as be honest, how many times have you worked in your part washer without them. The water based chemcial won't let you soak aluminuimm parts in them for extneded time periods, they will stain them, butIi use a secong biodegradalbe aluminum cleaner to soak aluminum parts in, I got fram a local chemical company.