Exposure Assessments Can Be Comprehensive and Cost-Effective
By: Tom Burgess, Contributor
As an industrial hygienist, I work with companies to ensure employees are not exposed to dangerous conditions at work. These conditions can include anything from chemical vapors to noise or heat. An exposure assessment process is used to understand worker exposures and potential health risks.
For some companies, the phrase “exposure assessment” might conjure a very technical and expensive procedure that involves taking air samples or performing other measurements and analysis. There can be very technical aspects to this process. But there are techniques in exposure assessment that take a simpler approach; they can be very practical and cost-effective.
From the Beginning: Survey
The process for exposure assessment recommended by the American Industrial Hygiene Association begins with a general, or qualitative, survey of the workplace, the workforce and the general environment of the site and tasks. This involves observation of the workplace; sources of exposure and controls; as well as interviewing workers, supervisors and managers about conditions, workflow and any safety procedures currently in place.
Some questions that are asked in an initial survey include:
- What are the types and sources of exposure?
- What are the potential health risks?
- Are there exposure limits to help understand acceptable levels of exposure?
- When are workers exposed—to how much—and for how long?
- Can you use odor or other observations to help you understand the exposures?
- What controls are in place, and how well are they working?
- What exposures occur during maintenance, cleaning or non-routine tasks?
Quite often, you can gain a good understanding of the nature of worker exposures and begin to sort out those that are a concern; the ones that are not a concern; and which need more assessment. Frequently, I get requests to do air monitoring before the initial assessment has been done. Without this initial qualitative part of the assessment, we may end up wasting time and money doing air monitoring in areas, or for tasks where an initial observation would have already told us exposures are acceptable.
A more technical and expensive analysis could, in fact, be necessary, but that time and effort can be targeted to areas where it can be the most beneficial.
The survey detailed above can often directly lead to practical and cost-effective improvements. In some cases, we may observe that a hazard can simply be eliminated or physically removed from a work area. In other cases, we might be able to keep workers out of a hazardous location, or limit the time they are exposed. We may also find that controls or PPE are not being used or are not effective. Making these improvements might not involve significant cost or require additional analyses.
Other effective solutions might involve building in physical safeguards; establishing new procedures to work more safely around hazards; or even providing personal protective equipment to workers. If workers are unnecessarily exposed to vapors when taking samples, for example, a company might consider investing in a sampling port for this procedure.
The exposure assessment procedure also helps to identify hazards that may be overlooked. One client was concerned about workers being overexposed to chemicals when loading chemicals into tanks during a chemical batching process. Observation of the process found that good controls were in place, including local exhaust ventilation and use of PPE. However, after watching the entire process from start to finish, it was clear that during cleanup following the loading of the tanks, workers were more exposed than during the original work.
With these observations, we were able to focus our improvements on the tasks which were resulting in the higher exposures. Full shift air samples alone would not have identified the specific tasks within the overall batch-making process that were causing the highest exposures.
Technical Expertise for Exposure Assessments
In some cases, exposure assessment does reveal the need for a more detailed, technical analysis to understand exposures and health risks before new controls or improvements can be implemented. In such cases, it’s vital that companies involve the right expertise in toxicology, engineering, ergonomics or chemistry for the job. It is also important to have employee involvement, as this will typically help with the implementation of controls.
While odors, visible dust or other indicators can help us observe the nature of some exposures, there are times that this will not be effective, and air monitoring or sampling may be needed. One equipment manufacturer was concerned with the many solvents with which they worked and, in particular, one substance that had a strong odor. When we reviewed the types of solvents they were using, it was actually a type with a low odor, (i.e., poor warning properties) that presented the greatest health risk. For the process that used that solvent, the initial survey found enough exposure potential that air samples were needed.
Moving Forward: Periodic Re-evaluation
It is critical that exposure assessments, and any controls implemented in response to these assessments, be periodically re-evaluated. Workflows and work conditions could change, for a variety for reasons, and these in turn could impact the types of dangers to which employees are exposed. A management of change process can be used to assess the potential health and safety impact of changes to equipment or processes before they occur. It is usually much more cost effective to integrate health and safety controls into a change than to try and add them on after the change has occurred.
Another manufacturer with whom I’ve worked wanted to bring in a new process that included a type of chemical they had not used previously. During the process design, they reviewed the process and hazards and found that there was the potential to generate potential hazardous vapors. Since this was identified early in the process, a lot of decisions could be made about the design—in order to minimize potential risk before design and installation was complete.
In this case, the client decided that industrial hygiene technical support was needed, and I was brought in to assist their team. We developed effective controls with a minimal cost impact. If the problem was found after the process was started, the same changes would have been costly and disruptive and, even worse, workers could have been overexposed.
While effective controls were implemented for this new process, this will still need to be re-assessed. The same type of qualitative assessments we discussed earlier should be done periodically. We may see that a control is not working or that some change has occurred.
Employee safety should be the top priority of any company, and many companies are willing to invest considerable resources to ensure their workers are not exposed to workplace hazards. But effective exposure assessments are not necessarily the most expensive ones. Effective exposure assessments are comprehensive, holistic and consider a wide range of factors.
Tom Burgess is a Client Manager at T&M Associates, a leading national consulting, engineering, environmental, technical services and construction management company.