Demystifying Occupational Hygiene

Written by Abimbola Badejo, Staff Writer

At the recent Partners in Prevention 2019 Health and Safety Conference, Ontario, Canada; organized by Workplace Safety and Prevention Services (WSPS) Ontario, Canada, Dave Gardner of Pinchin Ltd. delivered a presentation on Demystifying Occupational Hygiene. Mr. Gardner is Senior Occupational Hygiene and Safety Consultant with Pinchin Ltd. Below is a summary of his presentation.


Occupational hygiene has been defined by the United States Department of Labour Occupational Safety and Health Administration as “that science and art devoted to the anticipation, recognition, evaluation, and control of those environmental factors or stresses arising in or from the workplace, which may cause sickness, impaired health and well-being, or significant discomfort among workers or among the citizens of the community.1.   Simply put, the goal of Occupational hygiene is to ensure the safety and protection of a worker at his or her workplace, provided the worker follows a set of guidelines  that have been put in place to safeguard his/her health and safety.  

Typical occupational hygiene principles include written standards, procedures and practices; workers training as part of a knowledge management program; logical thinking on the part of the creator; a combination of actions with words learned from the written standards; and total compliance with associated regulations.


An Occupational Hygiene program is of great importance as its negligence leads to occupational injuries and diseases. Occupational diseases are considered more significant due to factors associated with it; which include

  • Diseases caused by exposure to either chemical, physical or biological agents at the workplace
  • Sources such as exposure to airborne asbestos particles, confined spaces, noise, construction projects, etc.
  • Categories namely Long Latency Illness, Noise Induced Hearing Loss (NIHL), Chronic Exposure and effects and Acute Exposure and effects
  • Observable effects which are not seen until after a long duration of exposure
  •  75% of fatalities in diseases, attributed to occupational origins

The Ontario Workplace Safety and Insurance Board (WSIB) reported that approximately 130 thousand claims were filed, and about $940 million benefit costs were released, between 2008 and 2017. Occupational diseases with long latency are mostly serious and these account for only three percent of the occupational diseases with benefits.

Based on these factors (and those not mentioned), reviews have been made by the Human Resources and Skills Development Canada (HRSDC) and Labour Canada. These reviews include updates made to the Occupational Exposure Limits (OEL) of chemicals, training workers on the safe usage of materials and the equipment at the workplace, thorough knowledge of the materials and substances used at the workplace, compulsory and proper use of Personal Protective Equipment (PPE), alertness of workers to the state of their own health and compulsory medical check-ups in relation to workplace risk assessment.


A survey made by the Center for Construction Research and Training regarding occupational diseases in the construction industry reported that the workers in this industry are:

  • twice as likely to have chronic obstructive lung diseases, five times more likely to have lung cancer, thirty-three times more likely to have asbestosis
  • inclined to suffer a 50% increase in Lung Cancer related deaths
  • predisposed to noise induced hearing loss (NIHL) (50% of workers)
  • susceptible to elevated levels of lead in their blood (17% of workers)
  • exposed to the allowable 8-hour exposure limit for Manganese during welding processes. This was observed with workers involved in boiler making (75%), iron-working (15%) and pipe-fitting (7%)).

In addition, a nationwide report has disclosed that 40% of WSIB costs are for construction occupational diseases, more construction workers die from a combination of occupational diseases and traumatic injuries and that 2 to 6 construction workers are more likely to develop occupational lung disease and NIHL.

As observed, most of the occupationally related diseases can be prevented by simple tasks such as hand-washing, proper use of PPE and correct compliance to defined regulations.


To ensure the protection of workers in various Canadian industries, regulations and guidelines have been put in place; some of which require compliance by either the employee or the employer. The legislations and related codes/standards guiding occupational hygiene in workplaces include:

Some of the provided regulations and guidelines are specific while others are general in application. The key to correct interpretation is to apply the correct regulation to the right workplace situation.

An example of a proper legislation application: Silica is an inert substance and an irreplaceable material in most products and buildings in the world today.  As the second most abundant mineral on the planet, silica is used in numerous ways. Getting the substance to the usable state requires processing, which exposes the worker to the respirable crystalline form. The regulation (O. Reg 490/09), listing silica as a designated substance, does not apply to the silica infused products but to the respirable fractions which the processing worker is exposed to. The regulation specifies an occupational exposure limit (OEL) for respirable crystalline silica as 0.05 mg/m3 of air (cristobalite silica) and 0.1 mg/m3 of air (quartz and tripoli silica) for an 8-hour/day or 40-hour weekly exposure. This regulation, however, does not apply to the employer or some other workers on a construction  project; but the employer’s responsibility will be to protect the worker’s health in compliance to section 25 (2)(h) of the OHSA, requiring employers to take every reasonable precaution in the circumstances to protect a worker.


Before initiating an occupational hygiene program, a clearer understanding of basic terms is ideal.

Industrial Hygiene: this is an exercise devoted to the anticipation, recognition, evaluation, and control of those environmental stresses arising from the workplace, which may cause the impairment of a worker’s health.

Toxicology: the study of how chemical, physical and biological agents adversely affect biological systems. The adverse effects include irritation, sensitization, organ failure, diseases or cancer.

Disease, dose and exposure: Disease / response is caused by an agent dosage. Dosage is measured in relation to the exposure of the worker to an agent. Mathematically, exposure is calculated as the agent concentration multiplied by duration of exposure (concentration x time). Therefore, sampling surveys are simply estimating the exposure of the worker to a specific concentration of the agent. Exposure routes may be through inhalation, ingestion, contact or skin absorption.

Threshold Limit Values (TLV): TLVs are general concentration limit values for specific chemicals, to which a healthy adult worker can be exposed.  However, TLVs does not adequately protect all workers as their susceptibility levels to various chemicals are unique to them. TLVs are used by regulators as guidelines or recommendations to assist in the control of potential workplace hazards.

Time-Weighted Average (TLV-TWA): TWA concentration for a conventional 8-hour/day or 40-hour/week , to which a worker may be repeatedly exposed.

Short-Term Exposure Limit (TLV-STEL): This is a 15-minute TWA exposure that should not be exceeded.

Ceiling (TLV-C): This is a concentration that must not be exceeded during any part of working exposure

Air Monitoring: This is a process of sampling the air in the workplace, on a regular basis. The monitoring  may be qualitative (risk assessments, hygiene walkthroughs and training) or quantitative (air, noise and wipe sampling) in perspective.


The first focus of an occupational hygiene program is to conduct a risk assessment of the workplace processes.  A risk assessment shows that 20% of the activities or tasks  carried out, leads to 80% of  risks. Carrying out a risk assessment, focuses on the adverse effects of  a hazardous agent and the associated level of risk if a worker is exposed to it. Approaches to risk assessment include Critical Tasks Analysis (where stepwise task and risk inventories are made with the focus on worker’s safety), Process Safety (where the focus is on the process, controlling the risk to keep the worker safe) or a combination of both approaches. Risk assessment, therefore, is done  as thus:

  1. Making a list of the agents the worker is exposed to,
  2. Identifying the routes of entry,
  3. Identifying a relative risk level (low, medium or high),
  4. Documenting the control in place and its effectiveness.

Table 1. Requirements of a Hazard Reviewer. Scores are used to dictate the skill level required to assess and develop control strategies.

Minimum Requirements
<10 Low to Medium low Any trained employee
>10 to <20 Medium Health and Safety Department or a contracted Health and Safety Consultant
20 & above High Certified Health and Safety Professional or Industrial Hygienist (CRSP, CSP, CIH, ROH)


A preliminary survey is initially conducted using simple and common tools such as human senses (sight, taste, hear, smell, taste and gut-feelings), video camera, photo camera, tape measure and a notebook. Optional tools include velometer and smoke tubes.

Next, all knowledge and processes related to the hazardous agents are sought out using the central dogma of risk assessment (Recognition, Evaluation and Control).

The sampling itself should be done using standardized and validated methods (NIOSH, EPA, ASTM, etc.).

The extent of sampling should be determined, whether personal (breathing zone) samples or area samples.

Next, the duration of sampling should be determined, which could be  a whole day, full-shift, partial shift, single samples, sequential samples, grab or composite samples.

The worker to be sampled should be with the worker with the  highest exposure potential or a group of workers with similar exposure due to the similarity of their tasks at the workplace.

The amount of samples taken should also be determined.

The time of sampling should be determined (day or night shift, winter or summer season, etc.)

Documentation should be made at every sampling point; and this should include start and stop times, environmental conditions, chronological log of work tasks, quantified conditions during production, duration of shifts and break periods, use of PPE, engineering controls, housekeeping habits and the state of workplace ventilation.


Occupational hygiene programs are made with several guidelines governing it. According to the province of Ontario, all control programs must provide engineering controls, work practices and hygiene facilities  to control a workers exposure to a designated substance; methods and procedure should be put in place to monitor airborne concentrations of designated substances and measure workers exposure to the same; training programs should be organized for supervisors and workers on the health effects of the designated substance and the respective controls required. A typical Occupational Hygiene program, therefore, should  include the following:

  • Version history
  • Purpose / objectives
  • Scope and application
  • Distribution
  • Definitions and abbreviations
  • Roles, responsibilities and accountabilities
  • Program management (Resources, commitment and program coordinator)
  • Risk assessments
  • Exposure monitoring plans
  • Occupational hygiene surveys (sampling strategy development, analytical services, documentation and reporting )
  • Occupational hygiene controls
  • Training
  • Related document / appendices
  • Quality assurance
  • Maintenance of standard operating practices (SOPs)
  • Annual summary report.


An occupational hygiene program is an important component of workplace management. This ensures the protection of workers’ health, which leads to better and greater productivity at the workplace.  The foundation of occupational hygiene programs is to understand the principles that govern the program and knowing how to apply the principles to various situations at the workplace. Proper application and effective controls will assist in achieving the goal of establishing a safe environment for workers to operate.



Canadian ban on asbestos and asbestos containing products

In the same week the cannabis became legal in Canada, the federal government announced the prohibition of asbestos and asbestos-containing products, according to a recent study published at  The government action is considered the final step in the prohibition of asbestos and asbestos-containing products in Canada.

These new regulations are part of the government-wide strategy announced in 2016 to protect Canadians from exposure to asbestos. The new regulations prohibit the import, sale, and use of asbestos as well as the manufacture, import, sale, and use of asbestos-containing products, with a limited number of exclusions.

In addition, exports of asbestos and asbestos-containing products are now prohibited, with a limited number of exceptions, and the existing Export of Substances on the Export Control List Regulations and schedule 3 of the Canadian Environmental Protection Act, 1999 were amended to reflect that.

The new regulations and related amendments will come into force on December 30, 2018.  They will protect the health of Canadians by preventing new asbestos and asbestos-containing products from entering the Canadian market.

“This is the final step to ban asbestos in Canada.  We have followed through on our promise to deliver new, tougher rules to stop the import, use, sale, and export of asbestos in Canada. These measures will protect our communities and the health and safety of all Canadians,” stated Catherine McKenna in a news release.

Quick facts

Asbestos was declared a human carcinogen by the World Health Organization’s International Agency for Research on Cancer, in 1987.  At the height of its use, asbestos was found in more than 3,000 applications worldwide.

The regulations do not apply to residues left from mining asbestos.  However, these asbestos-mining residues cannot be sold for use in construction or landscaping without provincial authorization, and they cannot be used to make a product that contains asbestos. The mining of asbestos in Canada ceased in 2011.

Risks related to asbestos-containing products that are already in use or installed—such as in existing buildings, equipment, and vehicles—will continue to be managed by existing federal, provincial, and municipal rules and regulations. There are no significant health risks if asbestos fibres are enclosed or tightly bound, in good condition, and left undisturbed.

The use, sale, and export of any asbestos-containing products that exist in inventories but that have not yet been installed are prohibited under the new regulations and related amendments.

The current Asbestos Products Regulations under the Canada Consumer Product Safety Act will be repealed as these new regulations are more comprehensive.

Real-Time Global Radon Map

Airthings, a company specializing in digital radon detectors, recently launched, a live global Radon map.  The map pulls constantly-updating Radon level data from Airthings’ devices all over North America, Europe ,and beyond to provide current localized analysis and advice – ideal for anyone looking to for the risks associated with radon exposure.

Facts about Radon

Radon is a radioactive gas that occurs naturally when the uranium in soil and rock breaks down. It is invisible, odourless and tasteless. When radon is released from the ground into the outdoor air, it is diluted and is not a concern. However, in enclosed spaces, like homes and offices, it can sometimes accumulate to high levels, which can be a risk to the health of the occupants of the building.

Radon gas breaks down or decays to form radioactive elements that can be inhaled into the lungs. In the lungs, decay continues, creating radioactive particles that release small bursts of energy. This energy is absorbed by nearby lung tissue, damaging the lung cells. When cells are damaged, they have the potential to result in cancer when they reproduce.

Exposure to high levels of radon in indoor air results in an increased risk of developing lung cancer. The risk of cancer depends on the level of radon and how long a person is exposed to those levels.

Exposure to radon and tobacco use together can significantly increase your risk of lung cancer. For example, if you are a lifelong smoker your risk of getting lung cancer is 1 in 10. If you add long term exposure to a high level of radon, your risk becomes 1 in 3. On the other hand, if you are a non-smoker, your lifetime lung cancer risk at the same high radon level is 1 in 20.

Radon Map aggregates radon level data from Airthings’ devices dispersed all over the world to provide accurate, local radon readings for users seeking current and reliable insight into the dangerous indoor gas and how much exposure they are subjected to daily.

Previously, gaining an understanding of localized Radon readings was only possible through professionally-administered tests or government data, offering a one-time snapshot rather than a constantly-evolving picture. With the introduction of the Airthings, radon levels and fluctuations can be tracked accurately through a community of user-generated data. instantly becomes a very reliable and up-to-date information source available for alerting the public about the presence of Radon in their environments and enabling them to take corrective action, if necessary, before a situation becomes critical.

About Airthings

Airthings is a Norwegian tech company that develops and manufactures both professional and consumer facing technology. These products include monitors for radon and other dangerous indoor air pollutants. The company was founded in 2008.

U.S. Eleventh Circuit Highlights Importance of Safety Training in Affirming Willful Violation of OSHA Standard

Author: H. Bernard Tisdale, Ogletree Deakins, Charlotte, North Carolina)

The Eleventh Circuit Court of Appeals recently had the opportunity to remind employers not to ignore training employees on safety. Martin Mechanical Contractors, Inc. v. Secretary, U.S. Department of Labor, No. 17-12643 (March 27, 2018).

In late 2015, a heating, ventilation, and air conditioning (HVAC) contractor was installing an HVAC system on the flat roof of a warehouse in Georgia. The installation was to take place adjacent to several unguarded skylights covered only with plastic sheeting. While the onsite foreman had fall protection equipment in his truck, the employees did not wear any fall protection equipment while on the roof. These circumstances ended in tragically: one of the workers fell through a skylight and died as a result of his injuries. This is why it’s absolutely paramount to ensure you contract the right people. I suggest you give a call to complete the work.

The Occupational Safety and Health Administration (OSHA) cited the employer for a willful violation of 29 C.F.R. § 1926.501(b)(4)(i) for failing to protect its employees from falls. The administrative law judge concluded the supervisor’s actions supported a willful classification in that he demonstrated a “reckless disregard for the safety of his crew.” The employer appealed.

To support a willful classification, OSHA must show either (1) the employer knew of the standard and consciously disregarded it or (2) it exhibited such reckless disregard for the employees’ safety that the employer would not have cared that the conduct violated the standard. Evidently, the supervisor claimed ignorance of the law, and the court analyzed whether the willful classification could be supported under the second standard.

Air conditioner units (HVAC) on a roof of industrial building

The court of appeals was unimpressed by the employer’s arguments. The court noted the supervisor was well aware of the danger posed by the unguarded skylights in that he warned his employees to be careful around them. The supervisor also testified it was his practice not to use fall protection equipment on flat roofs. The supervisor neither instructed anyone to wear fall protection equipment nor provided his employees with the fall protection equipment he had in his truck. Thus, the Court concluded, while the supervisor did not know of the standard’s requirements, he exhibited such reckless disregard for employee safety that he would not have cared that the conduct violated the standard.

This is where all employers may want to take heed. The court went on to observe that the supervisor’s “unfamiliarity serves, if anything, only to underscore the inadequacy of [the employer’s] training program. They really should have better knowledge of OH&S if they are running a business where safety is paramount. To hold that such inadequacy—and the resulting unfamiliarity—precludes classification of a violation as willful would perversely allow [the employer] to use its ineffective training as a defense against OSHA’s most serious charge.” The court upheld the willful classification.

Needless to say, a willful citation can have far-reaching ramifications for an employer—from tort liability and criminal penalties for the injury or death to inability to secure future work. While training may seem trivial and time consuming, doing it just might prevent a willful citation and possibly save a life.

This article was originally published on the Ogletree Deakins website.


About the Author

Mr. Tisdale has wide experience in general civil and employment litigation. This experience ranges from advising clients on preventive measures to avoid formal charges and lawsuits, and representing clients before the United States Court of Appeals, to handling individual employment discrimination cases before the Equal Employment Opportunity Commission and the federal courts as well as handling wrongful discharge and other employment-related litigation in state and federal courts. He regularly represents employers on safety and health matters including advising and defending clients on OSHA compliance issues involving Federal OSHA and state plan states. He regularly assists clients with contract disputes and non-compete and trade secrets advice and litigation. His experience also includes counseling clients on wage and hour compliance under the Fair Labor Standards Act and performing compliance audits under the FLSA, drafting and reviewing employment contracts and employment

U.S. EPA’s Enforcement of the Lead-Based Paint Renovation, Repair and Painting Rule

By Dianne R Phillips, Holland & Knight

On March 28, 2018, the Office of the Inspector General (OIG) of the U.S. Environmental Protection Agency (EPA) issued a Project Notification indicating its plans to begin preliminary research to evaluate the EPA’s implementation and enforcement of the Lead-Based Paint Renovation, Repair and Painting Rule (RRP Rule). The RRP Rule, which is part of the federal Toxic Substances Control Act, is intended to ensure that owners and occupants of pre-1978 “target housing” and “child-occupied facilities” receive information on lead-based paint hazards before renovations begin, that individuals performing such renovations are properly trained and certified, and that renovators and workers follow specific lead-safe work practices during renovations to reduce the potential for exposure to lead. Although use of lead-based paint in dwellings was prohibited after 1978, EPA estimates it is still present in approximately 30 million homes across the United States. The RRP Rule is intended to protect children and others vulnerable to lead exposure due to the health effects associated with lead poisoning.

Enforcement of the RRP Rule, along with the other lead-based paint rules, has been a priority of EPA. For fiscal year ending 2017, according to EPA’s Oct. 27, 2017 press release from October 2016 through September 2017, EPA finalized 121 civil settlements for alleged violations of one or more of the three lead-based paint rules–the RRP Rule; the Lead Disclosure Rule; and the Lead-based Paint Activities Rule for abatements–and filed three complaints for ongoing actions. EPA and the U.S. Department of Justice also prosecuted one criminal case involving violations of lead paint laws and finalized two Clean Air Act settlements that included lead paint abatement projects in local communities. The OIG Project Notification indicates that the “objective for this project is to determine whether EPA has an effective strategy to implement and enforce the lead-based paint RRP.” Only time will tell what is meant by that.


About the Author

Dianne R. Phillips is an attorney in Holland & Knight’s Boston office who concentrates her practice in litigation, regulatory, energy and environmental law. As former assistant general counsel for Suez LNG North America LLC (now known as Engie North America) and its wholly owned subsidiary, Distrigas of Massachusetts LLC, Ms. Phillips was involved in all aspects of regulatory compliance for the nation’s oldest, continuously operating liquefied natural gas (LNG) import terminal located in Everett, Mass., including safety and security. Her LNG experience includes advising clients with respect to specialized regulatory compliance under 49 C.F.R. Part 193 and NFPA 59A.

Surviving the OSHA Audit: Common Sense Solutions

Imagine for a moment it’s Monday morning. You’ve just arrived to work and you’re enjoying your first cup of coffee. Unexpectedly, you receive a call from the receptionist. The U.S. Occupation Safety and Health Administration (U.S. OSHA) has just arrived and they’d like to meet you to discuss a safety complaint they’ve received from an employee. Your day just got a little bit more complicated! So, what should you expect during the OSHA visit? What questions should you ask and perhaps more important, what should you avoid? What will OSHA want to see during their visit? Will they ask you for paperwork? Do you have that paperwork?

Within this book, respected OSHA consultant, David A. Casavant takes you behind the curtain and reveals exactly what happens during an OSHA inspection, rules for behavior during the audit and perhaps more importantly, what you can do now to comply with the often-complicated U.S. OSHA regulations. This essential guide simplifies complex regulatory law, provides commonsense strategies for compliance and should be included in every safety professional, risk manager, or attorney’s toolbox.

The author of the book, David A. Casavant is the Executive Director of the Sustainable Workplace Alliance, a 501(c)(3) not‐for‐profit organization dedicated to Health & Safety in the workplace. He is an authorized OSHA 500 & 501 trainer and in 2007, 2008 and 2010 his organization was awarded the prestigious Susan Harwood training grant from the U.S. OSHA. He has been a featured speaker at World WorkPlace, American Management Association, Rockhurst University, NeoCon, SkillTV, Total Facility Management Forum and the NFM&T conference. Additionally, Mr. Casavant has written hundreds of business related articles. His articles can be found in a number of trade publications including the Facility Management Journal, Buildings, PlantServices, SkillTV and Building Operating Management.

Soft cover, 313 pages
Copyright © 2017
ISBN 978-0-9987437-0-7

You can order the book through the American Society of Safety Engineers website.