Canadian Occupational Safety

July/August 2020

Canadian Occupational Safety (COS) magazine is the premier workplace health and safety publication in Canada. We cover a wide range of topics ranging from office to heavy industry, and from general safety management to specific workplace hazards.

Issue link:

Contents of this Issue


Page 20 of 31 21 clothing. But also, as you work, when you transfer a flammable liquid from one container to another, the liquid generates static electricity on its own. Going through pipes, it generates static electricity by itself. That's why there's always a requirement for grounding and bonding," he says. While transferring flammable liquids from one container to another, he adds, the containers must be electrically bonded to each other or electrically grounded. Sparks are generated by electrical equipment. There should never be any regular electrical equipment in areas where flammable liquids are handled or stored. "You need special electrical equipment — mortars, switches, wiring — that will not produce a spark. They're specially classified for flammable vapour environments. If a regular switch costs $5, this kind of switch will cost $500. It's much more expensive, but it's absolutely necessary," Fridlyand says. The work area should have explosion-proof ventilation, lighting and equipment. The ventilation system must be good enough to reduce concentration of vapours to a safe level — that is, well below the flammable limit. The type and design of the system will be determined by factors such as the nature of the work, the types and amounts of products used and the size and layout of the work space. "Any area where you're working with flammable liquids should have either local exhaust or general dilution ventilation to prevent the buildup of vapours," Hodgson says. Workers also need to keep flammable liquids away from incompatible materials, substances that may react dangerously with a flammable liquid, generating excessive heat and possibly fire. For example, oxidizers, which release oxygen, will act to keep a fire going and make it worse. Where there is a possibility of explosion, local codes may specify that the room or area has to be equipped with explosion-relief panels. "These are part of the wall structure and made of a lighter material. They're designed to be released at a certain predetermined pressure, and that prevents the collapse of the building. Otherwise, it would be like a bomb that would explode," Fridlyand says. Always dispose of rags soaked in flammable liquids in designated covered containers. Some flammable liquids, if left in waste materials, will slowly react with air and heat up enough to burn. Storage of flammable liquids When workers are handling small amounts of flammable liquids, the chance of a hazardous buildup of vapours is low. However, when liquids are stored, the quantities are larger and confined in a closed space, so the hazard from vapours building up becomes greater. Improperly stored flammable liquids can become a significant fire hazard. An undetected spill in a cabinet can also be dangerous. "With these liquids, the more surface area there is, the more spread out the liquid is, the faster they evaporate. So, if you have a small opening in a bottle, it evaporates at a certain rate. If that bottle spills and ends up [spreading] over a square metre, it's going to evaporate much quicker and create a more hazardous atmosphere," Hodgson says. Flammable liquids should be stored in areas that are cool, dry, well ventilated and away from ignition sources. They should be stored separately from incompatible materials. These liquids are often transferred from their original container — a drum or tank, for example — to a smaller container. Use only approved portable containers that meet the safety requirements set out in the regulations and codes of the local jurisdiction. There are several types of approved containers. Portable safety cans are a commonly used container and are designed for carrying, storing and dispensing flammable liquids. They have a spring-closing lid and spout cover, which automatically open when the vapour pressure builds up inside. This safety device prevents rupture (or explosion, in the event of fire). Containers should never be breakable. Containers of flammable liquid should always be closed and properly sealed. They should be regularly inspected for damage and always have WHMIS labels attached before being stored. Where there are larger amounts of liquids in a work shop or lab, the containers should be kept in flammable liquid storage cabinets. These approved cabinets are specially constructed and designed to protect the contents from fire and prevent the contents from contributing to a fire. Flammable storage cabinets should not be located near a room exit and must be labelled clearly, indicating that the contents are flammable. It's important to note that these cabinets are designed to protect their flammable contents from a fire — not to protect the people working nearby from the flammable vapours inside the cabinets. "Many people get that wrong. The reason for this is, if a fire breaks out in your shop, lab or office and it reaches the flammable liquids, the liquids can enhance the fire quickly. Using these flammable cabinets buys you an hour or two hour, depending on the cabinet, and gives you time to evacuate before the flammable liquids are ignited," Hodgson says. Emergency responses Employers must conduct a fire risk assessment and develop a fire safety plan that covers proper safe work, storage, maintenance and housekeeping procedures and make sure workers are trained in these procedures, Besliu says. They must also provide clear instructions on how to handle spills and fires, covering topics such as the location of the fire extinguisher, alarm sounding, exit routes and meeting points. The workplace should have a readily accessible extinguisher. "Workers must respond to a fire according to the procedures outlined in the fire safety plan. In general, the steps that should be followed are: Sound the alarm; try to extinguish the fire only if the fire is small, there is an appropriate fire extinguisher and you have been trained to extinguish a fire; if the fire cannot be controlled, evacuate, meet at the meeting point and wait for the fire department to control the fire," she says. It's really important, Hodgson says, for workers to not remain on site and try to extinguish a flammable liquid fire they may not be able to control. "People should not be heroes," he says, adding that everyone should focus on preventing the liquids from igniting. "Everything we do — installing ventilation, minimizing the quantity we work with, storing the liquids properly — all these things are about preventing fires." "You need special electrical equipment — mortars, switches, wiring — that will not produce a spark. They're specially classified for flammable vapour environments… It's much more expensive, but it's absolutely necessary." Simon Fridlyand, president of S.A.F.E. Engineering WHAT IS THE WHMIS? WHMIS is the Workplace Hazardous Material Information System. It is the regulatory requirement in Canada to classify chemical and biological agents and communicate their hazards. WHMIS has been updated to incorporate elements of the Globally Harmonized System (GHS) for Classification and Labelling Chemicals, which is used to classify chemicals and communicate hazards worldwide. Hazard classes are globally consistent between GHS and WHMIS. WHMIS 2015 incorporates the following GHS elements: Classification rules and hazard classes; hazard pictograms; supplier label requirements; and format of safety data sheets. Source: WorkSafeNB

Articles in this issue

Links on this page

Archives of this issue

view archives of Canadian Occupational Safety - July/August 2020