906 Oil Spill Cleanup

Exposure to Toxic Components

Cleanup operations may expose workers to various hazardous substances found in the environment, fuel vapors, and equipment exhaust.

Nitrogen Dioxide (NO₂)

Nitrogen dioxide (NO₂) is especially common in areas where machinery is running or controlled burns are used. It is a byproduct of combustion processes on drilling rigs, trucks, heavy equipment, generators, and compressors. For instance, cleanup crews may be exposed while using diesel-powered skimmers near shore. Workers downwind of exhaust in an area with little air movement may inhale NO₂.

The following are important facts about nitrogen dioxide:

• It is a gas with a distinctive reddish-brown color.
• It is heavier than air and can collect in low-lying areas where workers may be operating.
• It is one of several nitrogen oxides (NOx) that contribute to air pollution and respiratory irritation.
• In enclosed or poorly ventilated areas, NO₂ concentrations can build up quickly to hazardous levels.

Nitrogen Dioxide Health Risks

Burning crude oil produces nitrogen oxides (NOx), including nitrogen dioxide, which can harm nearby responders without proper respiratory protection.

• Nitrogen dioxide is a strong respiratory irritant. Inhalation may cause coughing, wheezing, and shortness of breath, especially in people with asthma or lung disease.

• Long-term or repeated exposure to lower concentrations can cause chronic lung damage or worsen existing respiratory conditions.
• The odor of NO₂ becomes noticeable to most people at concentrations between 0.11 and 0.22 ppm. However, depending on conditions, harmful effects may occur even before it is detectable by smell.
• Individuals with pre-existing lung conditions, such as asthma or COPD, may be at higher risk and should avoid areas where NO₂ levels may be elevated.

Occupational Exposure Limits (OELs)

OSHA and other regulatory agencies have set occupational exposure limits (OELs) for nitrogen dioxide to help protect worker health. These limits are typically based on normal work conditions in standard industrial settings.

• Short-term exposure (15 minutes): Acceptable concentrations range from 1 to 5 ppm, depending on the agency and job setting.
• Long-term exposure (8-hour time-weighted average): Limits typically fall between 3 to 5 ppm.

However, these limits may not fully account for the real-world conditions faced by oil spill cleanup workers. In many cases, responders may work extended hours, often more than 8 hours per day for several days in a row.

Standard OELs usually apply only to inhalation exposure and do not account for other routes of exposure such as skin absorption or ingestion. During oil spill operations, it is common for workers to come into contact with hazardous exposure above OELs.

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