In Ontario, the Ministry of Labour has exposure standards for about 600 chemical substances. There are three types of exposure standards which are the time-weighted average exposure value (TWAEV), the short-term exposure value (STEV) and the ceiling exposure value (CEV). The TWAEV is the standard for an all-day exposure, the STEV for a 15-minute exposure, and the CEV for a maximum instantaneous exposure. Exposures are measured in units of milligrams substance per cubic metre air (mg/m3), parts per million (ppm) or fibres per cubic centimetre air (f/cm3) depending on the airborne contaminant measured.
 
Some chemical substances have very low exposure standards like beryllium and some have quite high exposure standards like carbon dioxide. In most cases, chemicals with the lowest exposure standard tend to pose the most risk when airborne.
 
GTA Environmental has conducted numerous monitoring surveys for industrial, commercial, and institutional facilities. The basic types of survey data include personal exposure samples and area samples. Personal exposure monitoring involves placing air sampling equipment on people while they do their work. Area monitoring involves collecting air samples in the immediate vicinity of the workers. Sample duration can range from all-day to instantaneous depending on the survey purpose.
 
There are many types of substances that can be sampled for in the air. Typical substances and their associated processes are as follows:

	Carbon monoxide - Propane powered forklifts
	Metal fumes - Welding operations
	Total nuisance dust - Warehouse operations
	Fibreglass - Composite material production
	Solvents - Cleaning operations
	Acids - Laboratory testing
	Pesticides - Lawn and garden care

Whatever your air monitoring needs, GTA Environmental provides a cost effective approach to your survey requirements. We use certified labs for sample analysis and calibrated equipment for sample collection. We also provide a comprehensive report that includes the results, conclusions, and recommendations for management and the JHSC.
 
Call our office today to discuss your particular needs (905) 823-9137.