Hazards of Asphalt Fumes

Workers exposed to asphalt include on-roof workers, workers at hot-mix asphalt facilities, and roofing manufacturing facilities. Asphalt is used because it is adhesive, flexible, durable,  water resistant, and can be mixed with aggregate materials. There are three types of asphalt:  paving cements, cutback asphalts and emulsions which are mostly used in paving and roofing.

Breathing asphalt fumes can irritate the nose, throat and lungs causing coughing, wheezing and/or shortness of breath. Contact can irritate and cause severe burns of the skin and may cause dermatitis and acne-like lesions. Exposure to asphalt fumes can also cause headache, dizziness, nausea and vomiting. Because of the complex chemical composition of asphalt, it makes it difficult to pinpoint its components. Known carcinogens such as benzene and polycyclic aromatic hydrocarbons have been found in asphalt fumes generated at work sites. High exposures over time can have chronic health effects including cancer.

The Occupational Safety and Health Administration (OSHA) does not have a specific standard for asphalt fumes although the National Institute of Occupational Safety & Health (NIOSH) has a Recommended Exposure Limit (REL) for an eight-hour exposure of 0.5 milligrams per cubic meter (mg/m3). Industrial hygienists and safety professionals can use this standard as a reference point for employee exposures to asphalt fumes. They may also test for cancer causing vapors.

Depending upon the applications, there are a number of measures that can be implemented to lessen exposure.  Engineering controls include heating systems that maintain a constant asphalt temperature, emission capture through filtration, or local exhaust systems. Administrative actions include substituting low-fuming asphalt and limiting a worker's exposure time. Personal protective equipment includes wearing respiratory protection and protective clothing.

NIOSH has a number of reference materials that can be helpful in protecting workers including Asphalt Fume Exposures During the Application of Hot Asphalt to Roofs, Reducing Worker Exposure to Asphalt Fumes from Roofing Kettles, and the Asphalt Training Guide. There are a number of off-site and on-line training and courses and youtube.com has presentations on asphalt safety.

Exposure to asphalt can have negative health effects on workers. Recognizing work where exposures take place, implementing effective controls, and training workers on how to best protect themselves can allow employees to work with asphalt safely.