WHMIS and Cleaning Chemicals in Ontario Workplaces

Degreasers, descalers, floor strippers, disinfectants and bleach are everyday products for a cleaning crew, and many of them are hazardous. In Ontario workplaces, hazardous products are covered by WHMIS, the Workplace Hazardous Materials Information System. This guide explains what WHMIS requires for cleaning chemicals, who is responsible for what when a cleaning contractor works on your site, and the practical habits that prevent most chemical injuries.

WHMIS in one paragraph

WHMIS is Canada's hazard communication system for hazardous products used at work. The current version, often called WHMIS 2015, is aligned with the international Globally Harmonized System (GHS). Suppliers' duties are set federally under the Hazardous Products Act and the Hazardous Products Regulations. Employers' duties in Ontario are set under the Occupational Health and Safety Act and the WHMIS regulation (R.R.O. 1990, Reg. 860). It rests on three elements: labels, safety data sheets, and worker education and training.

Labels: supplier and workplace

A hazardous cleaning product arrives with a supplier label showing the product name, hazard pictograms, a signal word such as Danger or Warning, hazard and precautionary statements, and the supplier's details. The most common gap in cleaning is what happens next: product is decanted from a large jug into a spray bottle or a mop bucket. Under WHMIS, a hazardous product moved into another container generally needs a workplace label with the product name, safe handling information and a reference to the safety data sheet. An unlabelled spray bottle of clear liquid is exactly how products get mixed or misused.

• Label every spray bottle and secondary container with the product name and safe handling information
• Never reuse a labelled bottle for a different product
• Replace labels that are worn or unreadable
• Keep products in their original containers wherever possible

Safety data sheets

Every hazardous product must come with a safety data sheet (SDS) from the supplier. An SDS has 16 standard sections, including hazards, first-aid measures, handling and storage, and the personal protective equipment needed. Employers must make the SDS readily available to workers who use the product and to the joint health and safety committee or health and safety representative. For a cleaning contractor, that means SDSs for the products used on your site should be available on site or instantly accessible, not only in the contractor's head office.

Training

Workers who use or work near hazardous products must receive WHMIS education and training, including general WHMIS information and site-specific instruction on the products they use: how to read the labels and SDSs, how to handle and store the products, what PPE to wear, and what to do in an emergency. Generic training alone is not enough; workers need to know the specific products in their kit.

Who is responsible when a contractor cleans your site

When a cleaning company brings its own products onto your site, it is the employer of its cleaning crew and is responsible for labelling, SDSs and training for those products. As the host workplace, you still have a general duty to protect your own workers, which means you should know what chemicals are being used in your building, where they are stored, and how to find the SDSs. A good contract makes this explicit:

• A list of the products the contractor will use on site, with SDSs supplied
• Agreed storage location for the contractor's chemicals, locked if needed
• Notice before any new or stronger product, such as a floor stripper, is introduced
• Clear rules about which of the host's products the contractor may or may not use

Never mix: the reactions that cause injuries

Some of the most serious cleaning-chemical incidents come from mixing products, often by accident in a toilet bowl, a drain or a bucket. Two combinations every cleaner should know:

• Bleach (sodium hypochlorite) with ammonia or ammonia-containing products releases toxic chloramine gases
• Bleach with acids, including some toilet bowl cleaners and descalers, releases chlorine gas

The safe rule is simple: never mix cleaning products unless the label tells you to, rinse surfaces between products, and use one product at a time. Ventilate rooms while cleaning, especially small washrooms.

Dilution and PPE

Concentrated products are where most splashes and skin injuries happen. Dilute to the label rate, measure rather than pour freely, and add product to water rather than the other way round where the label says so. Wear the PPE that section 8 of the SDS lists. For many daily products that means gloves; for floor strippers and strong degreasers it often includes eye protection and more.

Disinfectants are regulated twice

Disinfectants are hazardous products under WHMIS where they meet the hazard criteria, and they are also regulated by Health Canada, which issues a Drug Identification Number (DIN) to approved disinfectants. The DIN tells you the product's disinfection claims are authorized; the SDS tells you how to handle it safely. A crew needs both pieces of information.

Storage

• Store cleaning chemicals in a ventilated area away from food, heat and public access
• Keep acids and chlorine products apart
• Keep lids closed and containers upright
• Clean up leaks in the storage area right away using the SDS instructions

When something goes wrong

If a worker is splashed or exposed, the first-aid measures are in section 4 of the safety data sheet, which is one reason it must be easy to find. Follow those measures, get medical help where needed, and report the incident under your workplace's procedures. Spills should be cleaned up using the method in the SDS, with the PPE it lists, and larger or unknown spills should be left to people trained to handle them.

Choosing lower-hazard products

The simplest way to reduce chemical risk is to carry fewer high-hazard products. Many daily cleaning tasks can be done with certified, lower-hazard general cleaners, keeping strong acids, strippers and solvents for the specific jobs that need them. Fewer products also means fewer labels to manage, fewer SDSs to keep current, and fewer chances of mixing.

Signs a chemical programme needs attention

• Unlabelled spray bottles or buckets left on site
• Workers unable to say where the safety data sheets are
• Products stored on the floor, in washrooms or near food
• Strong smells or complaints of irritation after cleaning
• New products appearing without anyone being told

Industrial and warehouse sites

Factories and warehouses often store their own process chemicals as well as cleaning products. Cleaning crews on those sites should never clean up an unknown spill; it should be reported to the site so the right SDS and method can be used. We follow that rule on our industrial cleaning services in Toronto.

The same approach, with safe zones agreed around forklift traffic and loading areas, applies to our warehouse cleaning services.

How CMG Clean handles it

Our crews are trained on WHMIS and on the products they carry, and safety data sheets for everything we use are available for your site. Where possible we use green-certified products for general cleaning, which reduces the number of high-hazard products a crew needs to carry. For more on certified products, see our guide to what ECOLOGO certification means.

This article is a plain-language summary, not legal advice. For your specific obligations, check the WHMIS regulation and guidance from Ontario's Ministry of Labour, Immigration, Training and Skills Development.