Hazardous or Toxic Substances

[OHS General Regs., S. x] Follow these links
to related legislation.
Highlighted words reveal
definitions and supplementary
information when selected.
A variety of products are used in many workplaces. Products that are classified as hazardous products under the federal Hazardous Products Act must meet the requirements for WHMIS. Other hazardous or toxic substances such as consumer products, pest control products, nuclear products, and food and drug products are only partially regulated by WHMIS. This topic describes the requirements for substances that fall in this gap or are regulated by other legislation.
Employer duties
Employers must take every reasonable precaution to protect the health and safety of persons at or near the workplace. [OHS Act, S. 12(1)(a)] Employers must make sure that all workers who use, store, transport, or dispose of a hazardous or toxic substance receive appropriate information and training about that substance.
In terms of these substances, employers must:
- Prepare a list of all biological, chemical, or physical agents that are used, produced, or present at the workplace that may be hazardous to the health and safety of workers, or are suspected of being hazardous by the workers. The list must identify all agents by their common or generic name if known. [OHS Act, S. 32(1)]
- For every substance, find out from the supplier, manufacturer, or other sources and record the following information: [OHS Act, S. 32(2)]
- Its ingredients and their common or generic names;
- Its composition and properties;
- The toxicological effects;
- The effects of exposure by contact (skin), inhalation, or ingestion;
- The measures used or to be used to protect workers;
- The emergency measures used or to be used; and
- Information about use, transport, storage, and disposal.
- Keep the list current. [OHS Act, S. 32(3)]
- Provide a copy of the current list to the committee or representative, if any, and on request to an OHS officer or worker. When information is not available, on the ingredients or composition of an agent, the employer will provide the officer with the trade name, and name and address of the manufacturer. [OHS Act, S. 32(3) and (4)]
- Supply and maintain, where reasonable and practical, changing rooms and showering facilities, where there is a high risk of workers being contaminated by a hazardous substance, infectious or other offensive materials that are regularly in the workplace. [OHS General Regs., S. 2.6(3)]
- Not allow hazardous liquids or gases, and explosives to be stored in excavations or trenches. [OHS General Regs., S. 12.6(2)]
Tanks and Vessels
When working in a tank, vessel, or chamber, workers must not enter a space that may contain toxic fumes or gases until it has been determined that the air is sufficiently pure. If in doubt, provide air-supplied respirators and lifelines, as part of a confined space entry procedure. [OHS General Regs., S. 40.3]
When tanks are used to store hazardous liquids, the tank must be prepared or repaired as follows: [OHS General Regs., S. 40.11]
- The tank must be drained as much as possible.
- The inlet pipes must be disconnected and blanked off or moved out of alignment or locked in the closed position.
- Residual liquid and sludge must be removed by workers stationed outside the tank through manholes or hatches. Using water from a hose with a curved nozzle to make sure all parts of the tank are thoroughly washed. Long handles spears may also be used.
- If steam is available, close all openings (except the vent pipe and steam outlet) and blow live steam into the tank for a time suitable for the conditions and nature of the liquid. Open lids or manhole plates during the last one/fifth of the steaming period.
- If steam is not available, keep the tank filled with flowing water for at least 24 hours.
- Thoroughly ventilate after steaming or flooding by forcing air or inducing a draft for at least 2 hours.
- After ventilation, have a competent person (or persons) examine the interior of the tank to make sure it is free from residue, as well as take and test air samples to make sure all hazardous vapours are removed.
- Repeat the steaming or flooding procedures if the tests show that there is still a presence of hazardous vapours or fumes.
Hazardous liquids
When storing hazardous liquids, the employer must make sure that tanks used for storage are: [OHS General Regs., S. 43.9]
- Labelled to identify the contents and nature of the hazards of handling the tank and the hazardous liquids.
- Located above ground or floor level.
- Supported so that if the tank leaks, the leak will be noticed.
- Surrounded with pits, catch basins, or depressions that are large enough to hold the entire content of the largest tank if there is a rupture.
- Covered with paint that prevents corrosion from moisture or fumes.
- Provided with stairways or permanent ladders and platforms where necessary, that allow for convenient and safe access to all parts of the tanks. The stairways and platforms must have railings, and the floors and platforms are preferably constructed of grating.
- Protected from low temperatures. [OHS General Regs., S. 43.10]
- Not placed above passageways. [OHS General Regs., S. 43.11]
- Be placed on foundations that will hold the content of the tank, and have overflow pipes that discharge to a safe place. [OHS General Regs., S. 43.14]
When tanks are used for storing non-flammable hazardous liquids are installed in pits below ground level, the pits must be made of concrete or masonry, and have enough space between the walls and tanks to allow a person to pass at any point. The tanks must be mounted 381 to 457 mm above the bottom of the well. [OHS General Regs., S. 43.12] All control valves must be placed or designed so that they can be turned without any person entering the pit, and have a locking device that is operated from outside the pit. [OHS General Regs., S. 43.13]
Tanks used to store corrosive or caustic liquids must have a permanently open vent pipe that is not smaller than 50 mm (2 inches) in diameter at the highest point in the tank, and a drain connection at the lowest point that discharges from the lowest point to a safe place. [OHS General Regs., S.43.15] The tanks must have the filling connection at the top and the discharge pipe 152 mm above the bottom. [OHS General Regs., S. 43.16]
When barrels or drums that contain flammable liquids are stored in special storerooms inside factories or in small, isolated storehouses that area must be fire-resistant, and the floor of the area must have a slope to a drain pipe that leads outside to a catch basin that is not connected to a sewer. [OHS General Regs., S. 43.17] The floor must be waterproof, with the waterproofing raised at least 76 mm up the side walls. The barrels or drums must be placed in cement platforms, concrete blocks, brick, and metal racks. [OHS General Regs., S. 43.18]
Drums that contain acids must be stored in cool places with the bung facing up. They should be opened carefully to relieve any internal pressure and sealed again each time the drum is moved, or once a week if stored. [OHS General Regs., S. 43.19]
Empty barrels or drums that contained:
- Flammable liquids must be stored for re-use with bungs or outlet plugs present so that they confine the flammable vapours. [OHS General Regs., S. 43.20] These barrels must be steamed before being crushed or broken up. [OHS General Regs., S. 43.23]
- Acids or other non-flammable liquids, if it is to be reused, must be cleaned promptly and stored away from other containers. [OHS General Regs., S. 43.21]
- Hazardous non-flammable liquids, if it is to be reused, must be cleaned promptly and stored away from other containers. [OHS General Regs., S. 43.22]
- Hazardous liquids, intended for further use, must be closely inspected for leaks and other defects. If it is to be used for a different liquid, it must be thoroughly cleansed with an appropriate neutralizing solution, steam, or boiling water, and drained, dried, and reinspected until the inside is entirely clean. [OHS General Regs., S. 43.24]
Worker duties
Workers must:
- Follow the instructions, education and training about air quality provided by your employer, and properly use any equipment that is required.
- Wear the personal protective equipment provided by the employer.
- Be aware of changing conditions and air quality.
- Report any hazards.
- Do not enter a restricted area without authorization and appropriate personal protective equipment, as required by the employer.