There are several characteristics that distinguish asphalt emulsions from other forms of bituminous paving materials, asphalt cements and cutbacks. The biggest single difference is the presence of water in asphalt emulsions. Most asphalt emulsions contain between 30 to 40% water, depending on the grade. The asphalt cements and cutbacks on the other hand cannot tolerate the presence of water or moisture.
The water constituent of emulsions is basic to many of the properties of these materials, both advantageous and otherwise. One of the prime advantages is safety. Emulsions are liquid at ambient temperatures and therefore require much less heat than asphalt cements when being handled and worked. Depending on the grade of product and the type of job, asphalt emulsions are typically used at temperatures between ambient and 185° F (85° C), while asphalt cements require much higher temperatures.
Asphalt cutbacks, like emulsions are liquids at ambient temperature, but have the disadvantage of being flammable because of the petroleum solvents present.
From a safety standpoint, the emulsions have the best of two worlds. They may be used at comparatively low temperatures thus reducing the danger of people being badly burned when inadvertently splattered or drenched. Because the medium used in emulsions is mostly water, they are non-flammable and therefore are more difficult to flash or burn when overheated.
Emulsions, although inherently safer than most other forms of asphalt, like all construction products must be handled with reasonable care. The use of protective clothing (long sleeves, rubber gloves, goggles, etc.) will protect the skin from accidental contact. In the event that the skin is splashed with emulsion, the area should be flushed well with water to remove most of the unbroken emulsion. Any remaining residue can be removed by the use of a suitable hand cleaner or baby oil. If the eyes are part of the affected area, flush well with water and consult a physician.
In case of a spill, the best method is to contain the spill with an absorbent solid, such as sand or dirt. The resulting mix may then be picked up and disposed of in accordance with local regulations.
AEMA recommends the following additional precautions in the handling of asphalt emulsion: