About NRCA | Insurance and safety | NRCA Special Reports and updates |

Special Report:Asphalt fumes |

Sample Building Occupant Notification Letter

[Date]

Dear Occupant of [Building name and/or address]:

[Your company name] has been hired to [repair/replace] the roof of [building name and address; specify units if a partial job] with a new asphalt roof [provide details if applicable]. For more than 100 years, asphalt's durability, value and superior water tightness have made it the leading choice for roofing applications. However, heating asphalt to the temperature required for roofing applications produces a fume that some people find to be unpleasant.

Asphalt fumes are known to irritate the eyes and mucous membranes of the nose and throat of some individuals. In addition, experience has shown that some individuals are much more sensitive to asphalt fume emissions, and you may wish to take extra measures to avoid fume exposure and minimize any discomfort for them.

Work is scheduled to begin [start date] and end [projected finish date]. During this time, [describe any applicable conditions, such as closure of entrances; or recommendations, such as keeping windows closed]. Throughout the course of the job, [your company name] will work closely with building management to ensure that disruption to building occupants is kept to a minimum.

Should you have any questions, please call us at [company phone number] from [company hours]. We apologize for any inconvenience you may experience while we apply your new asphalt roof system.

Sincerely,

[Your name]

[Your company name]

---

What are Asphalt Fumes?

Asphalt is an extremely complex mixture of petroleum compounds. Some asphalt occurs in natural deposits in the earth. However, today nearly all asphalt is made by processing crude oils in petroleum refineries. When asphalt is heated, some of the asphalt turns into vapor and escapes into the air. When it mixes with the cooler air above a roofing kettle or tanker, some of the vapor cools back into liquid and forms a cloud of tiny droplets. Fumes are actually tiny droplets of airborne liquid asphalt. Exposure occurs when these droplets are inhaled or land on a person's skin.

Asphalt is used in a variety of roofing-related products, including shingles, built-up roofing and modified roofing felts, some single-ply membranes and flashing materials. Many of these products do not generate fumes in the field because they are not heated. Asphalt is also used in roof coatings, mastics and cements; these products release vapors that are different from asphalt fumes as they come from the petroleum solvent and not from the asphalt itself.

Asphalt fumes are created during the installation of hot-applied built-up roof systems as well as some modified bitumen and single-ply roofing membranes. Asphalt fumes are not created during the removal of these systems because the asphalt is not heated during a removal operation. As with any tear-off operation, particulates (dust) may become airborne, but there is no evidence that asphalt particulates pose a health risk to workers, beyond the possible effects of over-exposure to any general "nuisance" dust.

Safety Hazards

Among the most serious hazards facing a roofing crew is the risk of getting burned by hot asphalt. Skin contact with hot asphalt, which may be heated in excess of 400 F, can lead to very serious burns. Your professional roofing contractor will work with you to be sure that no building occupants or passersby are exposed to the risk of spilled asphalt.

Health Hazards

Fumes from asphalt can cause irritation of the eyes and mucous membranes of the nose and throat. Exposure to asphalt fumes may give some people headaches or make them nauseated. All of these effects typically go away once the person is no longer exposed to the fumes, and pose no known long-term health consequences.

Some scientists and advisory bodies, however, have expressed concern about whether exposure to asphalt fumes may pose a cancer risk to workers. Nonetheless, when all the evidence available today is considered as a whole, the prevailing view is that although the possibility of a cancer hazard cannot be ruled out scientifically, the current information is insufficient to conclude that asphalt fumes pose a cancer hazard to those who may be exposed to them. Several widely-respected scientific advisory bodies have concluded that asphalt fumes cannot be classified as a human carcinogen, and recently the National Institute for Occupational Safety and Health (NIOSH), while concluding that fumes from roofing asphalts are "possible occupational carcinogens," suggests that additional studies be conducted to "better characterize occupational exposures to asphalt fumes, vapors, and aerosols, and to further evaluate the risk of chronic disease, including lung cancer."

The NIOSH report recommends that workers using hot roofing asphalts have an exposure limit of 5.0 milligrams per cubic meter of air over any 15-minute time period. Because there is no available method for measuring total particulate exposure over a 15-minute period, there are no data available that indicate whether current exposures adhere to the REL.

Reducing Exposures to Asphalt Fumes

Because exposure to fumes from roofing asphalts can be an irritant for some people, your professional roofing contractor will work with you to find the best ways to reduce the possibility of any discomfort for your employees. There are several things that your contractor can do:

• Work with you to be sure that all points of air intake into the building are closed to the extent possible.
  
  
• Keep the asphalt heating equipment away from building intakes, and in an area that is acceptable for all parties in the roofing project. Restrict access to the equipment from anyone except the contractor's employees.
  
  
• Keep lids and covers on containers of hot asphalt (especially kettles) closed whenever possible.
  
  
• Use insulated pipes to transport hot asphalt from the ground to the roof, so that the temperature required to heat the asphalt can be kept to a minimum.
  
  
• Consider the use of kettles with engineering controls to reduce fume emission, or the use of fume recovery equipment.
  
  
• Consider the use of a low-fuming asphalt.
  
  
• Have a trained and skilled crew that is experienced in working with hot asphalt.
  
  

Finally...

The most important thing a professional roofing contractor can do is work with his clients to be sure that everyone involved in the roofing project understands the scope of the job, the hazards that may be present, and the approach that the contractor intends to take. You should be sure you are comfortable that you know the contractor's game plan, and that you stay in communication with the contractor as your project proceeds.

For More Information

There are a number of industry sources that can provide more information about the proper use of roofing asphalts. These include:

National Roofing Contractors Association
10255 W. Higgins Road
Rosemont, IL 60018
Phone: (847) 299-9070

The Asphalt Institute
2696 Research Park Drive
Lexington, KY 40512
Phone: (606) 288-4960

United Union of Roofers, Waterproofers and Allied Workers
1660 L Street, NW, Suite 800
Washington, DC 20036
Phone: (202) 463-7663

Asphalt Roofing Manufacturers Association
Center Park
4041 Power Mill Road, Suite 404
Calverton, MD 20705
Phone: (301) 348-2002