2.2: Chapter 3 Key Terms and Standards - Industrial Hygiene

Flash Cards-Key Terms and Definitions

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Hazard Categories

Physical Hazards

Physical hazards are the most widely recognized hazards and include contact with equipment or other objects, working at heights, and slipping. This category also includes noise, vibration, temperature, electricity, atmospheric conditions, and radiation. Canadian Occupational Health and Safety (OHS) practitioners have also included the design of work and the workplace as physical hazards, suggesting it is important to attend to the ergonomic effects of work. OSHA address ergonomic workplace hazards in terms of the injury as musculoskeletal disorders(MSDs). In this context ergonomic hazards will be defined as physiological hazards as it combines both physical workplace design and the use of the body within the design to describe these hazards.

When identifying and classifying physical hazards it is important to remember not just the "physics" of the characteristics but also how we "see" the hazard. Physical hazards also sometimes hide in plain sight. Often a hazard is so pervasive or workers’ behaviors to avoid the hazard are so routinized that the hazard is rendered almost invisible. For example, workers in a kitchen may use a dishtowel when opening an oven door to prevent the hot handle from burning them. Habitually turning a dishtowel into PPE prevents the injury and renders the hazard invisible. When identifying physical hazards, it is important to adopt the outlook of someone new to the workplace to bring back into view any hazards that have become invisible over time.

Chemical Hazards

Chemicals are everywhere in the modern workplace, from printer toner to engine exhaust to sink cleaners. While most chemical exposures do not cause ill effects, some certainly do. As we saw in Chapter 3, chemical hazards cause harm to human tissue or interfere with normal physiological functioning when they enter our bodies. Some chemicals irritate our tissue while others poison our systems or organs. Chemicals can asphyxiate us or negatively affect the functioning of our central nervous systems. Chemicals can also cause our immune systems to overreact, change our DNA, cause cancer, or damage a fetus.

There are four routes of entry by which chemicals can get into a worker’s body, the most common being through respiration (i.e., breathing in contaminated air) and absorption through the skin. Chemicals can also enter our bodies through ingestion (i.e., we can eat them—usually accidentally) and through cuts in our skin. Our bodies excrete some chemicals in our sweat, exhaled breath, urine, or feces, while retaining other substances. Our bodies metabolize some chemicals into other substances, which may be more or less toxic than the original substance.

Chemical hazards have varying levels of toxicity (i.e., ability to cause injury). Toxicity can be local or systemic. Local toxicity is a reaction at the point of contact. For example, you might experience a burn on the skin of your fingers after handling spicy peppers in a restaurant kitchen. Systemic toxicity occurs at a point in the body other than the point of contact. Allergic reactions after prolonged exposure to latex would be an example of systemic toxicity (see Note 2.2.1). Another example might be organ damage following skin absorption of a pesticide while picking fruit.

Note 2.2.1 Contact dermititis among food service workers

Many food service workers cope with a chronic rash on their hands. This dermatitis is caused by exposures to chemical substances such as cleaners and food products as well as by frequent handwashing—all of which can irritate a worker’s skin. Workers can develop severe itching, burning, flaking, cracking, blistering, and bleeding of their hands. Over time, repeated exposures to chemical substances can also make workers allergic to those chemicals. Allergic reactions mean workers can develop symptoms on other parts of the body.

Other factors appear to play a role in food service workers’ propensity to develop dermatitis. Extreme temperatures (such as hot dishwater and serving dishes as well as cold freezers), mechanical trauma (such as friction, pressure, abrasions, and lacerations) and biological agents (such as bacteria on meat and vegetables) are common food service hazards. Each of these hazards can increase the likelihood of workers developing dermatitis.

Some food service workers wear latex gloves as a form of PPE in order to reduce their contact with chemical substances. Latex gloves are also widely used by health care workers. Ironically, latex gloves themselves contain multiple chemicals (called rubber accelerators). These chemicals have allergenic properties and may contribute to the skin damage that gives rise to dermatitis. Workers can also become allergic to the latex gloves themselves, an allergy that can subsequently be triggered by household, recreational, medical, and clothing items. Proper skin care combined with eliminating or reducing exposures to the chemical, physical, and biological hazards of food service is likely to be more effective in reducing the incidence of dermatitis.

As was also discussed in Chapter 3, controlling chemical hazards begins by identifying worker tasks and environmental factors associated with the location. Subsequently, we must identify and list each chemical a worker is exposed to and the route(s) of entry for that chemical. The potential hazard posed by each exposure and the risk of exposure should be determined along with control strategies. Control strategies used should follow the hierarchy of controls, beginning with elimination (e.g., using non-chemical processes) and substitution (e.g., using a less hazardous chemical), then progressing to engineering controls (e.g., physically isolating workers from the chemical).

Biological Hazards

As we saw in Chapter 4, biological hazards are organisms or the products of organisms (e.g., tissue, blood, feces) that harm human health. There are three types of organisms that give rise to biological hazards:

• Bacteria are microscopic organisms that live in soil, water, organic matter, or the bodies of plants and animals. For example, the E. coli bacterium lives in human and animal digestive tracts and some strains can cause food poisoning, infections, or kidney failure when ingested.
• Viruses are a group of pathogens that cause diseases such as influenza (the “flu”) when they enter our bodies.
• Fungi are plants that lack chlorophyll, including mushrooms, yeast, and mold (sic). Many fungi contain toxin or produce toxic substances. For example, stachybotrys chartarum (black mold (sic)) produces toxins called mycotoxins that cause nausea, fatigue, respiratory and skin problems, and organ damage when the toxic spores are inhaled.

Insect stings and bites, poisonous plants and animals, and allergens are also biological hazards. Like chemical hazards, biological hazards can enter our bodies via respiration, skin absorption, ingestion, and skin penetration and can cause both acute and chronic health effects. Our bodies do have mechanisms by which to cope with some biological hazards. For example, our respiratory system has five layers of defence to prevent harmful particles from entering our body, beginning with the hair-like projections (cilia) on the cells that line our airways (which filter out particles) and ending with cells (macrophages) in the air sacs (alveoli) of our lungs that trap and route impurities into the lymphatic system for disposal. Organisms that enter our body are also subject to attack by our immune system. Yet these mechanisms are not effective against every biological hazard or every exposure.

Like all workplace hazards, control strategies for biological hazards should follow the hierarchy of controls. Historically, the provision of adequate washing and toilet facilities was an engineering control that significantly reduced worker exposure to many biological hazards. Recent technological improvements, such as automatically flushing toilets and automatic taps, soap dispensers, and towel dispensers, have further limited workers’ contact with bacteria in washrooms.

As noted in Box 2.2.2, providing workers with vaccinations is an administrative control that can reduce worker susceptibility to viruses. Mandatory vaccinations are, however, controversial. Public health officials in Alberta, Canada have been attempting to increase the rate of annual vaccination for influenza among health-care workers (HCP) (which sits at about 55%) and are considering mandatory vaccinations. In the US overall, 81.1% of HCP reported receiving influenza vaccination during the 2018–19 season, similar to reported coverage in the previous four influenza seasons (5). As in past seasons, the highest coverage (97.7%) was among HCP with workplace vaccination requirements and the lowest (42.1%) among those working in settings where vaccination was not required, promoted, or offered on-site. In Canada and the US, healthcare workers who do not receive a flu shot must wear a mask when interacting with patients.

Note 2.2.2 Communicable diseases, immunization, and childcare workers

Public immunization programs during the latter half of the 20th century—focused specifically on vaccinating school children—have largely eliminated diseases such as polio and smallpox. While primarily aimed at controlling disease in the broader population, vaccination programs have also reduced occupational exposures to biological hazards among health-care and child-care workers.

A since-discredited 1998 study that linked autism to the MMR (mumps, measles, and rubella) vaccine has contributed to declining vaccination rates in Canada and the United States. Fewer immunized children means that child-care workers—95% of whom are female—are increasingly exposed to biological hazards that can cause diseases, such as hepatitis B and measles.

Indeed, child-care workers face many biological hazards in the course of their daily work. Respiratory infections—spread through the air—are commonplace among children, as are measles, chicken pox, and whooping cough. Intestinal infections can be spread through contact with feces during diapering or through inadequate hand washing. And skin infections (such as ring worm) and infestations (such as lice) can be transmitted through direct contact.

Following a 2014 outbreak of measles in Disneyland linked to unvaccinated children, the State of California made vaccination of school-aged children mandatory. The state has since enacted further legislation requiring child-care workers to be vaccinated against measles, whooping cough, and influenza. Mandatory worker vaccination (which is controversial) helps to control some of the biological hazards faced by child-care workers. Other administrative controls include environmental monitoring and sanitization protocols, such as ensuring that there are adequate facilities for diapering and toileting and physically separating these areas from food preparation and eating areas.

The interaction of public health campaigns (such as immunization) with workplace OHS demonstrates the need for OHS practitioners to be mindful of health issues beyond the workplace. In Chapter 8 (workbook), we’ll examine the issue of pandemic planning in emergency planning. Pandemics are caused by the widespread outbreak of a new strain of a virus that spreads quickly (due to a lack of immunity) and for which there is no immediately available vaccination. While they are relatively rare, the workplace impact of a pandemic could be severe and many employers have developed plans for coping with such an event.

Pyschological (Pyscho-social) Hazards

Psycho-social hazards are the social and psychological factors that negatively affect worker health and safety. Psycho-social hazards can be hard to isolate in the workplace because they reside in the dynamics of human interactions and within the internal world of an individual’s psyche. Yet it is increasingly recognized that social and psychological aspects of work have real and measurable effects on workers’ health. Harassment, bullying, and violence are examples of psycho-social hazards. Other forms include stress, fatigue, and overwork. Even the absence of social interaction, in the form of working alone, produces its own hazards. Much of the challenge is recognizing that these hazards pose real threats to workers’ health.

A worker experiencing domestic violence or a worker with two or more jobs, or a worker in an environment in which they are racialized minority may conceal or appear to not be under any stress giving the false impression that all is well. These examples exhibit varying forms of stress.

There are four types of stressors:

• Acute stressors are time-specific events of high intensity and short duration that occur infrequently, such as a performance review, a car accident, or unexpected encounter.
• Episodic (or daily) stressors may be similar to acute stressors but occur more frequently, have a longer duration, and may be of lower intensity. Making repeated requests of a worker to work overtime is an example of an episodic stressor.
• Chronic stressors are stressors that persist over a sustained period of time, and include job insecurity, work overload, or lack of control.
• Catastrophic stressors are a subset of acute stressors but differ in their intensity, threatening life, safety, or property. Robbery and physical assault are examples of catastrophic stressors.

And stress often leads to fatigue. Fatigue is the state of feeling tired, weary, or sleepy caused by insufficient sleep, prolonged mental or physical work, or extended periods of stress or anxiety. Acute, or short-term, fatigue can be caused by failure to get adequate sleep in the period before a work shift and is resolved quickly through appropriate sleep. Chronic fatigue can be the result of a prolonged period of sleep deficit and may require more involved treatment. Chronic fatigue syndrome is an ongoing, severe feeling of tiredness not relieved by sleep. The causes of chronic fatigue syndrome are unknown.

While lack of sleep is the primary cause of fatigue, it can be enhanced by other factors, including drug or alcohol use, high temperatures, boring or monotonous work, loud noise, dim lighting, extended shifts, or rotating shifts. As with other conditions, workers have differing sensitivity to fatigue. Fatigue can also make workers more susceptible to stress and illness.

Fatigue is a legitimate health and safety concern because workers who are experiencing fatigue are more likely to be involved in workplace incidents. Lack of alertness and reduced decision-making capacity can have negative effects on safety. Research has shown that fatigue can impair judgment in a manner similar to alcohol.

Note 2.2.3 Responses to harmful work environments

When a worker experiences any OHS hazard, including harassment, bullying, or a toxic workplace, the worker can respond in a range of ways. In examining individual behaviour in response to deteriorating conditions, Albert Hirschman first developed the notion that people respond either through exit or voice, and the choice is determined by attitudes toward the situation. Others later added to Hirschman’s theory by positing two other options, patience (sometimes referred to as loyalty) and neglect:

• Exit: The worker decides to get away from the undesired situation, either by quitting the employer or transferring to another location or job within the same employer.
• Voice: The worker decides to speak up in an attempt to change the situation. Voice can take a number of forms, including attempting to repair the situation directly, lodging a complaint, filing a grievance or, less constructively, retaliating with their own inappropriate behaviour.
• Patience: The worker decides to do nothing in the hopes that the situation will eventually improve. Workers adopt a patience approach when their loyalty to the organization or the cost of exiting is greater than the price of experiencing the negative situation.
• Neglect: The worker does nothing, based on the belief that the situation will not change or might grow worse. The worker might try to avoid the source of the situation but will generally take no action to change the situation. Workers choose this option when the costs of exiting are too high and their relationship to the organization is sufficiently damaged to prevent either voice or patience.

Workers may adopt different strategies when confronted with bullying behaviour or may cycle through the various options. For example, a group of workers facing a co-worker who undermines them in meetings, makes false claims about their work performance, and verbally attacks them may react in different ways. Those workers who are not very invested in the workplace (e.g., they are new or they feel they have options elsewhere) may simply start looking for a new job.

Other workers may at first choose patience (in the hope the worker’s behaviour will change) and then move to voicing their concerns (e.g., filing a complaint or by socially excluding the bully). If the issue remains unresolved, some workers (e.g., those close to retirement) may choose neglect while others will move to exit the workplace.

Recognizing that workers might respond in four different ways to the same negative situation reminds us that there is no single “sign” of a poor workplace environment. Employers interested in preventing harassment and bullying must be careful to observe the myriad ways in which workers react to deteriorating situations.

There are several ways to address harassment and bullying in the workplace. First, an employer should (and, in some jurisdictions, must) develop policies regarding harassment in the workplace. The administrative controls should outline acceptable and unacceptable behaviours and actions, indicate employer and worker responsibilities, and create a process for investigating and resolving complaints. Any investigation must proceed in a manner that is transparent, fair to both parties, and as confidential as is possible. Investigations should also identify the root cause of the incident and how to prevent similar incidents in the future.

Workplace policies are important, but they are only as effective as the degree of their implementation and enforcement. Effective policy implementation requires the employer to train all workers, including managers, on how to prevent and address harassment. Training for managers is particularly important. It can help managers spot possible harassment and teach them the difference between legitimate management discretion and bullying management techniques. Training workers around respectful interactions and cultural sensitivity can help distinguish between legitimate interpersonal conflict and bullying and harassment.

Finally, research shows that the leading indicator of workplace bullying and harassment is the organization’s climate. In workplaces where workers feel unsafe, incidents of bullying and harassment are more frequent. Conversely, creating a safe and respectful climate increases workers’ sense of safety and lowers the negative consequences of bullying and harassment. Creating a safe workplace climate is a multi-levelled process, requiring a high degree of commitment to respectful interactions, clear communication, transparent management, and individual and collective accountability.

Ergonomic (Physiological) Hazards

Injury that results from external physical stresses on the body produced by working environments that allow for awkward postures, repetitive motions, heavy lifting, bending and pushing, overreaching are characterized as ergonomic or physiological hazards. The hazard is in 'how" the body is used when it is performing work, activity, or task and the 'way' the work is done that results in soft tissue musculoskeletal disorders.

Ideally, ergonomics starts with job design. Job Design comprises the decisions employers make about what tasks will be performed by workers and how that work will be performed.

Job design includes establishing the physical dimensions of work. This includes the size and location of the workspace, and what furniture, tools, and equipment will be used, as well as the temperature or lighting of the workspace. Job design also determines the nature of the tasks, including their complexity, pace, and duration and how individual tasks and jobs relate to one another. Finally, job design often includes making decisions and assumptions about the characteristics of the workers who will perform the work, including their height, weight, sex, and other physical and mental abilities.

The decisions made during job design can have significant effects on workers’ health and safety. Poor work design has negative effects on worker health. For example, if you have ever worked at a job where, at the end of the day, your eyes hurt (due to poor lighting) or your back was sore (because of standing on a cement floor), you have experienced ill health caused by poor ergonomics.

A core principle of ergonomics is “fit the job to the worker, not the worker to the job.” More specifically, ergonomics seeks to ensure that the design of work matches the anatomical, physiological, and psychological needs of the worker. Yet some ergonomic hazards are easier to “see” than others. For example, back pain from heavy lifting is easier to identify than fatigue to due poor shift rotation design. The broad acceptance of lifting as hazardous and requiring control shows that the relationship between the hazard and the injury is both direct and well accepted. By contrast, there are many factors contributing to worker fatigue. This makes it difficult to definitively prove that shift rotation is an important factor in worker fatigue.

The aspects of ergonomics that have been more readily adopted are the design of tools, equipment, and workspaces. For example, we have seen an increase in more appropriately designed keyboards, work stations, retail scanners, and other equipment. There has also been greater attention paid to minimizing manual lifting and handling of loads. Buildings are being built with better climate and air-quality control.

Employers have been more reluctant to address other ergonomic issues because the required changes affect the work process or may impede management’s ability to direct work. For example, providing a better-designed chair to prevent spinal deterioration is easier and cheaper than altering the work flow to reduce the mechanical forces exerted on workers’ spines by twisting to reach objects. This reluctance to address some ergonomic hazards echoes employers’ preference for PPE over engineering and administrative changes.

A common health effect of poor ergonomic design is repetitive strain injury (RSI). RSIs (which are sometimes called cumulative trauma disorders) are injuries to muscles, nerves, tendons, or bones caused by repetitive movement, forceful exertions and overuse, vibration, and sustained or awkward positions. RSIs frequently occur in the hands, wrists, and arms but can also afflict legs and other key joints. Carpal tunnel syndrome, frozen shoulder, trigger finger, tendonitis, bursitis, and (more recently) Blackberry thumb are all examples of RSIs.

Any task that requires either the same movement over and over again or puts the body in an awkward position can lead to RSIs, especially if repeated over a long period of time. RSIs have only gained acceptance as the outcome of workplace hazards over the past 20 years. They were first acknowledged in factories with workers on assembly lines. Even today workers in some occupations, such as retail clerks, typists, and restaurant servers (notably occupations dominated by women), still have greater difficulty having RSI claims accepted. Among the reasons for the slow acceptance of RSIs is the murky causality of the disease: did you get it from keyboarding at work or playing squash on your own time? RSIs may also worsen even after the hazardous tasks are eliminated and can appear as a result of work not normally associated with repetition. There has been inadequate epidemiological research into the full range of factors that lead to RSIs.

Hazard Communication Standard

1910.1200(a)

Purpose.

1910.1200(a)(1)

The purpose of this section is to ensure that the hazards of all chemicals produced or imported are classified, and that information concerning the classified hazards is transmitted to employers and employees. The requirements of this section are intended to be consistent with the provisions of the United Nations Globally Harmonized System of Classification and Labelling of Chemicals (GHS), Revision 3. The transmittal of information is to be accomplished by means of comprehensive hazard communication programs, which are to include container labeling and other forms of warning, safety data sheets and employee training.

1910.1200(b)

Scope and application.

1910.1200(b)(1)

This section requires chemical manufacturers or importers to classify the hazards of chemicals which they produce or import, and all employers to provide information to their employees about the hazardous chemicals to which they are exposed, by means of a hazard communication program, labels and other forms of warning, safety data sheets, and information and training. In addition, this section requires distributors to transmit the required information to employers. (Employers who do not produce or import chemicals need only focus on those parts of this rule that deal with establishing a workplace program and communicating information to their workers.)