Many employers and workplace professionals share a common question when they hear the term industrial hygiene or industrial hygienist: What is it exactly?

Industrial hygiene is the art and science concerning the anticipation, recognition, evaluation, control, and confirmation of protection of environmental workplace factors or stresses in the workplace that may impact workers’ health. Industrial hygienists are subject matter experts in industrial hygiene and can be viewed as more of the engineering side of occupational safety and health management. Simply stated, industrial hygienists help employers quantify employee exposure to physical, chemical, and biological hazards relative to established exposure limits and reduce or mitigate exposure through various controls.

Why Industrial Hygiene Matters

Industrial hygiene is critical to ensure workplace protection and OSHA regulatory compliance. Many physical, chemical, and biological hazards have established occupational exposure limits (OELs) developed by organizations including the National Institute of Occupational Safety and Health (NIOSH), American Conference of Governmental Industrial Hygienists (ACGIH), Occupational Health and Safety Administration (OSHA), and others.

OSHA’s OELs are known as Permissible Exposure Limits (PELs) and are enforceable in a workplace. OSHA PELs are known to be the minimum level of protection and are typically the least conservative regarding requirements for worker protection.

Noise, welding fumes, gypsum, silicon, sucrose, asbestos, benzene, airborne particulates, silica, lead, vapors, and ammonia are just a few examples of the many substances that have specific OSHA-required exposure limits.

Factors Affecting Workplace Exposure

The goal of exposure limits (generally) is to protect workers for their entire working lifetime, approximately 40 years, factoring in an eight-hour shift and a five-day workweek. Exposure limits are usually presented as the average concentration over an eight-hour workday within a 40-hour workweek. Employers using non-standard work shifts such as 10-12 hour shifts must factor irregular shift work into their workplace evaluations. OSHA’s exposure limits can include a ceiling value not to be exceeded, a short-term exposure limit (STEL) of a 15-minute time-weighted average (TWA), or a 480-minute or full shift TWA. OSHA requires employers to be fully aware of the physical, chemical, or biological characteristics of many substances or hazards in their work environment and associated employee exposure. Acute or chronic exposure exceeding established limits can result in adverse health effects and is highly dependent on the agents involved concentration, and duration of exposure.

Workplace exposure will vary based on a multitude of different factors such as product usage, process characteristics, task performance, variation in environment, task duration, personal protective equipment, ventilation characteristics, atmospheric conditions, shift work schedules, task variation, etc. Exposures must be characterized across an organization, including where exposures differ among workers or groups of workers and factor intermittent exposure periods and the entirety of exposure. For example, maintenance employees, office employees, full-time positions performing specific tasks occasionally or all day every day, part-time workers, or contractors who occasionally help with specific processes can have different exposures to the same physical, chemical, or biological agents in the same work environment.

Elements of Exposure Characterization

Thorough characterization, accurate measurement, and analysis are the foundation of understanding workplace exposure. When these elements can be properly performed, exposures can be classified relative to established occupational exposure limits as acceptable, uncertain, or unacceptable. Management teams can then make educated decisions to prioritize worker protection, including monitoring ongoing or escalating into necessary mitigation controls. Common mitigation controls include process modification, product substitution or elimination, engineering controls such as barriers or ventilation, training, policy or administrative controls, and personal protective equipment, including respirators. Frequently, cost-effective solutions can be identified before escalating into costly mitigation controls with the use of subject matter experts.

Basic characterization involving the workplace, workforce, and environmental agents should identify the following:

  • Chemical, physical, and biological agents that exist within the work environment
  • Health effects of these agents on employees
  • The occupational exposure limit for each agent
  • Sources of exposure of each agent to employees
  • Workforce organization with exposure to these agents
  • Processes involved with the agents of concern
  • Tasks performed that are associated with each agent
  • Exposure controls, including personal protective equipment that is in place
  • Exposure history, including OSHA 300 logs, previous exposure assessments, employee complaints, and near-miss accidents
  • Exposure duration of employees, including routine and non-routine work

Similar Exposure Groups (SEGs)

After a basic characterization, workers are stratified into groups based on expected exposure, known as Similar Exposure Groups (SEGs). Once finalized, SEGs are prioritized for further evaluation.

Measurement and Sampling for Exposure Assessment

Exposure determination frequently requires accurate measurement using instrumentation to gather data. Accurate measurement and sampling must consider available analytical methods, instrumentation measurement methods, equipment limitations, media limitations, proper calibration and alignment with the selected analytical methods, laboratory accuracy, and limit of detection. Sampling must factor all information within the basic characterization and measurement research (among other factors) and produce a sampling plan. This plan can consist of a significant number of methods or a combination of methods that may use various pieces of direct reading instrumentation, area samples, personal samples that range from several minutes to a full shift measuring to gather exposure data of a process, job type, specific tasks, individual, group, or SEG.

Challenges in Exposure Assessment

An exposure assessment to determine exposure relative to employees within complex processes can be complicated. Measurement and data analysis should not be attempted by someone who is not a subject matter expert. A poorly performed exposure assessment and conclusion underestimating exposure can lead to staff that are not protected in their work environment; conversely, an exposure assessment overestimating the exposure can lead to unnecessary and costly mitigation controls. Good industrial hygiene management evaluates exposures knowing that in the future, exposure limits are trending to be more restrictive and factor in the necessary sample size of the workforce.

Pitfalls of Poorly Performed Exposure Assessments

It is not uncommon in the industry that an exposure assessment is poorly performed, which is then revealed during an audit, industrial hygiene review, OSHA citation, or worker injury. Typically, we find in these previously performed assessments that after a single and sometimes partial shift sample has been performed, compliance with an exposure limit has been determined. This is often erroneous due to many factors, leaving the employer with non-compliance, escalated liability, and potentially harming employees. This evaluation method is frequently known as worst-case scenario sampling, and studies have found it can be highly inaccurate in performance.

Conducting exposure assessments in-house can be challenging for the reasons outlined above, and data analysis can become quite involved. Many employers are choosing to augment their Safety/HR/Engineering Departments, incorporate an outside industrial hygiene consultant as an alternative, and use them as needed for assistance, especially in addressing compliance gaps.

Read More: Industrial Hygiene and Compliance

Industrial Hygiene Services and Benefits

No industrial hygiene project is the same, and services performed by insurance organizations, internal company resources, or consultants can vary dramatically based on education and experience backgrounds. Employers should evaluate the credentials of those performing industrial hygiene work for their organizations, preview previous work samples, and non-subject matter experts should be avoided.

Various studies have shown that a return between $2-$6 will occur for every dollar invested in workplace safety. Properly performed industrial hygiene services can help reduce and eliminate organizational liability, increase regulatory compliance, reduce workers’ compensation claims, and, most importantly, keep employees safe.

Find out how we can help you with industrial hygiene by contacting us today.