Green Job Hazards
Biofuels: Chemical Reactivity Hazards
Biofuel manufacturing processes can present reactive hazards. While ethanol production by fermentation involves biological reactions that do not present an explosive “run-away reaction” hazard, some processes for making ethanol from materials such as wastepaper and wood chips use concentrated acids and bases, which can react vigorously with many materials. Also, the gases produced during ethanol fermentation need to be properly vented to avoid overpressuring equipment and piping.
Biodiesel is produced by the chemical reaction of organic oils with an alcohol, typically using a strong base as a catalyst. The glycerin that is co-produced with the biodiesel is then often treated with acid. These reactions need to be carefully controlled.
Failure to control potentially dangerous chemical reactions can lead to the rupture of equipiment and piping, explosions, fires, and exposures to hazardout chemicals. Employers need to protect their workers from these hazards. Engineering and administrative controls to keep the process within safe limits include: controlling the rate and order of chemical addition, providing robust cooling, segregating incompatible materials to prevent inadvertant mixing, and the use of detailed operating procedures.
There are several OSHA standards that address potential reactive hazards, including:
29 CFR 1910.119 Process Safety Management of Highly Hazardous Chemicals
29 CFR 1910.147 The control of hazardous energy (lockout/tagout)
Facilities with reactive chemicals may be covered by 29 CFR 1910.119, Process Safety Management of Highly Hazardous Chemicals (PSM) standard. This standard is described in OSHA publication 3132. Additionally, the OSHA Process Safety Management web page has useful information and links on preventing catastrophic incidents, including those involving reactive hazards.
OSHA’s Safety and Health Topics page on Chemical Reactivity Hazards offers useful guidance on applicable standards, hazard recognition, and hazard control, as well as links to external resources.
Hazards that are not addressed by specific OSHA standards still need to be controlled. Under Section 5(a)(1) of the OSH Act – the “General Duty Clause,” employers are required to provide workers with a place of employment which is free from recognized hazards that are causing or are likely to cause death or serious physical harm to employees.