Diesel exhaust

Scope

Diesel exhaust isn’t just a puff of smoke from a tailpipe. It’s made up of many particulates and gases that can be toxic and hazardous if inhaled or ingested by workers. Heavy equipment operators, construction workers, truck drivers, dock workers, agricultural workers, railway workers, and vehicle maintenance workers are especially susceptible to carbons, hydrocarbons, ash, sulfates, and other compounds in diesel exhaust.

Regulatory citations

• 29 CFR 1910 Subpart H — Hazardous Materials
• 29 CFR 1910 Subpart I — Personal Protective Equipment
• 29 CFR 1910 Subpart Z — Toxic and Hazardous Substances
• 29 CFR 1910.94 — Ventilation
• 29 CFR 1926 Subpart D — Occupational Health and Environmental Controls
• 29 CFR 1926.57 — Ventilation

Key definitions

• Administrative control: A type of workplace hazard control that uses procedures, policies, supervision, scheduling, and training as a means of protecting workers.
• Engineering control: A type of workplace hazard control that places barriers between the worker and the hazard, such as guarding or eliminating harmful machinery or chemicals.
• Particulate: An extremely small substance.
• Permissible Exposure Limit (PEL): The maximum allowable legal limit for employee exposure to a substance, chemical, or other physical agents that are potentially harmful.

Summary of requirements

OSHA requires employers to monitor hazards in the workplace and protect workers from exposure to diesel exhaust that exceeds PELs. Industries with workers that are especially susceptible to diesel exhaust exposure include construction, vehicle maintenance workers, railroads, oil and gas, agriculture, truck drivers, manufacturing, mining, and marine terminal operations.

Unprotected workers can experience dizziness, headaches, eye and nose irritation, coughing, and long-term cardiovascular or respiratory complications caused by the harmful effects of diesel exhaust. Use engineering controls such as exhaust filters, clean engines, and proper ventilation. Adding administrative controls such as routine maintenance, using special fuels such as biodiesel, implementing work procedures, and limiting speeds further increase protection for workers. When engineering and administrative control methods don’t provide adequate protection, use PPE as a last line of defense to protect workers.

Protect workers from exposure to diesel exhaust components that exceed OSHA permissible exposure limits (PELs) of 50 parts per million (ppm) carbon monoxide, 25 ppm nitric oxide, and 5 ppm ceiling nitrogen dioxide. Ensure to protect workers with appropriate, well-fitted respiratory protection. This involves:

• Ensuring appropriate Personal Protective Equipment (PPE), especially respiratory protection, to protect from diesel fumes and particulates.
• Confirming proper engineering controls are in place for ventilation, filtering, and exhaust containment.
• Reducing diesel emissions by using cleaner fuels, including natural gas or propane.
• Maintaining and repairing or replacing older vehicles or engines that emit unnecessary exhaust.
• Implementing administrative controls to protect workers from exposure.
• Educating workers on PELs, diesel exhaust particulates, and the protocols that prevent negative health effects.