Safety Office, Commissary Building
University of Waterloo
200 University Avenue West
Waterloo, Ontario, Canada N2L 3G1
Phone 519 888 4567 Ext. 33587
Fax 519 886 8082
Email: safety@uwaterloo.ca
Roofing repairs and re-roofing of University buildings are of vital importance to stop water damage and mould growth in buildings. This page contains more information on roofing projects at the University.
Roofing asphalt is a petroleum-based product. It is not a single chemical, but a mixture containing many different chemicals. During roofing projects, asphalt is heated in roofing kettles which generate odours from fume and vapour emissions. Due to the low odour threshold of the sulfur compounds in asphalt, odours can at times be very strong, resulting in building occupants reporting health symptoms.
Roofing asphalt fumes and vapours can cause headaches, dizziness, nausea and lung irritation. They may also irritate the skin, eyes, nose and throat. These effects are usually mild and temporary. Although building occupants may experience discomfort, the fumes and vapours generally do not pose a health hazard. Symptoms should resolve within hours after exposure to the odour has ended.
However, some individuals with medical conditions, especially respiratory conditions, may have their conditions aggravated by roofing asphalt fumes. These individuals should avoid inhaling roofing asphalt emissions and review with their supervisor any accommodations required in their work schedule or location.
Hydrogen sulfide is a by-product of the heating process of asphalt. Only levels inside an enclosed roofing kettle may be high enough to pose a serious health threat.
While roofing workers may be exposed to asphalt fume and vapour emissions at a significant level, building occupants should not have significant exposures. In Ontario, the American Conference of Governmental Industrial Hygienists (ACGIH) occupational exposure limit over an 8-hour workday and 40-hour work week has a threshold limit value (TLV) of 0.5 mg/m³(2008). Under this limit, workers exposed are not expected to experience adverse health effects. Building occupant exposure is generally accepted to be significantly below the TLV, even though odours may be strong. Long-term health effects in building occupants are not anticipated. Some studies show a higher incidence of certain cancers in asphalt workers, however, asphalt fume and vapour emissions are not classified as a human carcinogen.
Safety Office, Commissary Building
University of Waterloo
200 University Avenue West
Waterloo, Ontario, Canada N2L 3G1
Phone 519 888 4567 Ext. 33587
Fax 519 886 8082
Email: safety@uwaterloo.ca
The University of Waterloo acknowledges that much of our work takes place on the traditional territory of the Neutral, Anishinaabeg and Haudenosaunee peoples. Our main campus is situated on the Haldimand Tract, the land granted to the Six Nations that includes six miles on each side of the Grand River. Our active work toward reconciliation takes place across our campuses through research, learning, teaching, and community building, and is co-ordinated within the Office of Indigenous Relations.