Working safely with hot asphalt
Hot asphalt is a sticky, black substance made from crude oil that is used for paving, roofing and waterproofing, as well as in some glue products. (Asphalt is often confused with coal tar, also known as “pitch,” but coal tar is made from coal, not oil, so the hazards are different.)
Asphalt is manufactured in solid or semi-solid forms, and is blended with hazardous solvents, including styrene, naptha, toluene and xylene before use. Styrene, for example, is very toxic and can cause nerve damage. In addition to the toxic chemicals, crushed rock and sand are added as binders, bonding and hardening agents. Dust from the crushed rock may contain asbestos or silica, both of which can cause lung disease.
Working with hot asphalt
Asphalt is heated to between 250 and 325 degrees Fahrenheit for paving applications and can exceed 450 degrees when used for roofing, so burns are on obvious risk. When working with hot asphalt, proper personal protective equipment (PPE) is critical.
To work safely around hot asphalt, avoid direct skin contact at all times and use thermally insulated gloves. The solvents in asphalt can soak through cotton or leather gloves. Wear coveralls or a long sleeve shirt and long pants with no cuffs. Keep your shirt collar closed and your sleeves rolled down. And finally wear steel-toed safety shoes and a face shield.
If you do come in contact with hot asphalt, rinse the affected area for at least 15 minutes with water, and seek proper medical attention depending on the seriousness of the burn. Don’t eat, drink, or smoke while working with asphalt. Wash your hands thoroughly before touching your face or eyes and make sure anything you put in your mouth has not been contaminated.
In addition to the risk of burns and skin irritation, asphalt fumes given off by hot asphalt are a serious risk. Hot asphalt can produce several toxic gases, including hydrogen sulfide and various carcinogens. At a minimum, these asphalt fumes can result in coughing, a scratchy throat and lung irritation. Prolonged exposure can lead to allergic reactions, emphysema, bronchitis, suffocation and even death.
Avoid breathing these hazardous asphalt fumes. Stay up wind of hot asphalt as much as possible, and never put your head near a mixing container or lean over a kettle. Do not work with asphalt in a closed environment. Whenever fumes are unavoidable, use the proper respirator, not a dusk mask. Be sure the respirator is in proper working order before you use it.
To determine the potential safety risks associated with the asphalt materials you are working with, read the Material Safety Data Sheet (MSDS). The MSDS will explain the risks and prevention measures that are appropriate for the substances/chemicals you are working with and are developed for all materials that a worker may come in contact with, regardless of the risk potential.
The Occupational Safety and Health Administration (OSHA) mandates proper handling and preventative measures to avoid injuries and disease when working with hot asphalt . OSHA limits asphalt exposure to 5 milligrams of asphalt fumes per cubic meter of air, averaged over an eight-hour shift for all workers that may be exposed. This is called the Permissible Exposure Limit (PEL). If you are working with the various solvents or chemical agents mentioned above, the PEL is much lower and in those instances a respirator alone may not be adequate. If you need help to determine the PEL or what type of PPE is needed, contact your local OSHA office.
The last risk that occurs while working with hot asphalt is fire. Fumes produced while blending or heating asphalt are flammable and, in some cases, explosive. Working safely with hot asphalt includes taking basic precautions like not smoking, welding, brazing, or doing any activity that result in sparks. Keep the work area well ventilated so fumes don’t accumulate, and always have fire extinguishers nearby.
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—Por Bruce Webb