NIOSHTIC-2 Publications Search

Safety and chemical exposure evaluation at a small biodiesel production facility.

Law BF; Pearce T; Siegel PD

J Occup Environ Hyg 2011 Jul; 8(7):D68-D72

https://doi.org/10.1080/15459624.2011.584841

20038948

Biodiesel is a renewable fuel produced when agricultural feedstocks such as vegetable oils, rendered animal fats, and used cooking oils are reacted with alcohol in the presence of a catalyst to form fatty acid esters, glycerin, and soap in a process known as transesterification. Because of economics and process considerations, methanol is the most commonly used alcohol in the transesterification process producing fatty acid methyl esters.(1) Potential hazards of biodiesel production include (1) use of large quantities of methanol, (2) use of caustic chemicals as catalysts, (3) physical hazards, and (4) potential exposure to aldehydes. The biodiesel industry recognizes its most significant hazard as methanol. The properties of methanol, both physical and chemical, make it a particularly hazardous chemical. Methanol is highly flammable, and exposures can cause a wide range of deleterious health effects. It is easily absorbed by all routes of exposure. Methanol is metabolized to formaldehyde that is then converted to formic acid, which can accumulate in the human body. Methanol toxicity is mediated, in large part, by the formic acid metabolite. Studies have shown that short-term inhalation exposure to 200 ppm methanol results in blood methanol concentrations of less than 10 mg/L with no observed increase in blood formic acid concentration.(2) Acute methanol toxicity includes visual disturbances leading to blindness, mild dermal irritation, dizziness, giddiness, permanent motor dysfunction. and possibly death.(3-5) Chronic exposure to methanol may result in headache, dizziness, giddiness, insomnia, nausea, gastric disturbances, conjunctivitis, visual disturbances, and blindness.(3) The Occupational Safety and Health Administration (OSHA) permissible exposure limit (PEL) and the National Institute for Occupational Safety and Health (NIOSH) recommended exposure limit (REL) for methanol is 200 ppm time-weighted average (TWA). The short-term exposure limit (STEL) for methanol is 250 ppm; the concentration that is immediately dangerous to life and health (IDLH) is 6000 ppm.(6)

Fuel-production; Fuels; Agriculture; Agricultural-products; Foodstuff; Fatty-acid-esters; Oils; Fats; Alcohols; Glycerides; Soap-products; Methyl-compounds; Aldehydes; Biological-material; Biochemistry; Case-studies; Catalysis; Hazardous-materials; Biohazards; Chemical-composition; Chemical-properties; Toxic-effects; Exposure-assessment; Exposure-limits; Time-weighted-average-exposure; Permissible-limits; Short-term-exposure; Lethal-concentrations

Brandon F. Law, NIOSH-HELD/ACIB, 1095 Willowdale Road, MS 4020, Morgantown, WV 26505

JOEHA2

67-56-1; 50-00-0; 64-18-6

20110701

Journal Article

bh17@cdc.gov

Couch-J

2011

7

1545-9624

HELD; DRDS

Manufacturing

Journal of Occupational and Environmental Hygiene

WV