A brief report in the Journal of the American Medical Association (JAMA) points out that biodiesel is a substance that needs to handled carefully.
The article points out an incident in Colorado where a biodiesel homebrewer accidently left the heating element on while he left for the weekend. The resulting fire released biodiesel, recycled restaurant cooking oil, smaller amounts of glycerin and sodium hydroxide, and 1-gallon containers of sulfuric and phosphoric acid that seeped into the ground. There were no injuries or evacuations, but JAMA says that biodiesel should come from commercial sources:
Biodiesel usually is produced commercially; however, some persons in the United States and elsewhere produce biodiesel in their homes for personal use. Those who produce homemade biodiesel should be aware of the substantial risk for injury. Substances used in biodiesel production can be highly explosive (i.e., methanol) or corrosive (i.e., sodium hydroxide). If improperly handled, these substances can cause severe eye, skin, and upper respiratory irritation; chemical burns; and other serious injuries. During the preceding 10 years, almost all fires and injuries caused by home production of biodiesel of which the National Biodiesel Board (NBB) is aware were caused by improper handling of methanol during production.
Sounds like the old advice from Hill Street Blues… “Let’s be careful out there.”