Health Canada has published a residential indoor air quality (IAQ) guideline for toluene exposure. Canadian Gazette, Part I (7/12/11) at 16. The guideline, published under subsection 55(3) of the Canadian Environmental Protection Act of 1999, recommends an eight-hour exposure concentration limit of 15 milligrams per cubic meter (mg/m3) or 4.0 parts per million (ppm) and a 24-hour exposure concentration limit of 2.3 mg/m3 or 0.6 ppm. Assessed under Canada’s First Priority Substances List in 1992-1993, toluene was found not to be toxic. It was, however, identified in 2007 as a priority indoor air contaminant under the Regulatory Framework for Air Emissions.
Toluene is found primarily in the indoor environment in building materials and consumer and automotive products. According to Health Canada, studies have found that toluene exposure causes eye, nose and throat irritation, and headaches and dizziness. It has also purportedly been linked to neurological effects such as poorer performance in tests of short-term memory, attention and concentration, visual scanning, perceptual motor speeds, and finger dexterity in the completion of physical tasks.