Working safely with chemicals to prevent occupational disease

Photo: © NVB Stocker/Adobe Stock

When chemicals are used, stored, or generated in the workplace, there are unique hazards. Some have properties that make them an immediate safety concern, such as explosive, flammable, and corrosive chemicals. Others cause adverse health effects on our organs and body systems. Adverse health effects may result in occupational diseases ranging from contact dermatosis to cancers.

Over the last several decades, research has helped us better understand why certain illnesses are common in certain occupations. It has also led to advances in preventing occupational disease through the implementation of control measures, like using alternative chemicals that are less harmful.

Identifying hazards and assessing risk
Each workplace is unique. Employers have a responsibility to recognize the hazards by identifying all chemicals that are used, stored, handled, and generated in their workplace. They must also assess the risk of exposure to chemicals for their specific workplace, considering both the likelihood and severity of the exposure. These risks will depend on the chemicals present, the type and duration of the tasks being performed, the work environment, and other workplace-specific factors. Once risks are assessed, they must implement appropriate control measures following the hierarchy of controls (more on this below). In some situations, additional information such as occupational hygiene monitoring is needed to assess the hazard.

Understanding routes of exposure is another key part of the risk assessment. Inhalation is the most common, followed by contact with skin or eyes. Unintentional ingestion can happen if food, hands, or cigarettes are contaminated, workers should never drink, eat, or smoke in areas where they may be exposed to chemicals. Injection is a less common method of exposure, occurring when a sharp object punctures the skin and injects a chemical directly into the bloodstream. Regardless of how the chemical gets into the body, once inside it is distributed by the blood stream. In this way, the chemical can harm organs, which are far away from the original point of entry, and where it entered the body.
In some cases, it may be years between the time of exposure to the chemical and the development of a disease. This time is known as the latency period. Many occupational diseases have longer latency periods – they tend to be detected after prolonged exposure over time, making it challenging for researchers to track and study the effects of individual chemicals.

General health and safety when working with chemicals
After the hazards and risks of chemicals have been identified and assessed, appropriate control measures need to be put in place to protect workers. It is important to control the hazards by considering the most effective measures first, also known as the hierarchy of controls.

Elimination and substitution are the first and most effective control measures in the hierarchy, which involve removing the hazardous chemical from the workplace or replacing it with a less hazardous one. If elimination or substitution is not feasible or if there is remaining risk, the next most effective measure is engineering controls. These include design updates or modifications to plants, equipment, ventilation systems, and processes that reduce the source of exposure. Administrative controls, the third most effective measure, alter the way the work is done, including timing of work, policies and work practices. Work practices involve standard operating procedures such as housekeeping, equipment maintenance, personal hygiene practices, workplace-specific procedures, and training. It is critical that employers provide education and training about the potential hazards of the products and how to work with them safely. Training should cover safe work practices, procedures first aid measures in case of exposure, and how to respond to spills.

The last control measure to consider when other controls are unable to adequately protect workers is personal protective equipment (PPE).

Putting theory into practice
Workplace hazard control should be overseen and implemented by qualified individuals, and in consultation with health and safety committees or representatives, supervisors, and workers. It is also important to always follow the requirements of the applicable occupational health and safety legislation, fire codes, building codes, standards, environmental regulations, transportation of dangerous goods (TDG) regulations, and industry good practices.

When developing procedures for proper storage and disposing of a chemical, follow the recommendations from sections seven and 13 of the Safety Data Sheet (SDS), along with any regulatory requirements, standards, and codes for your jurisdiction. Ensure all containers are clearly labeled to avoid misuse or incidents.

When working with a chemical, make sure the necessary controls are followed to limit exposure, as outlined in your workplace’s procedure for the specific chemical and task. This will include requirements for ventilation, proper storage and disposal procedures, and the kind of PPE that needs to be worn. Encourage workers to report any concerns to a supervisor. They can also speak with their health and safety committee or representative for guidance on how to work safely with chemicals.
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The Canadian Centre for Occupational Health and Safety (CCOHS) promotes the total well-being — physical, psychosocial, and mental health — of workers in Canada by providing information, advice, education, and management systems and solutions that support the prevention of injury and illness. Visit www.ccohs.ca for more safety tips.