Containment: What is the Difference between OEB and OEL

In manufacturing, where potentially hazardous substances are handled, concepts such as Occupational Exposure Bands (OEB) and Occupational Exposure Limits (OEL) play a crucial role in employee safety. The two terms, OEB and OEL, are often used interchangeably, but there are clear differences.

What does OEB mean?

OEB stands for Occupational Exposure Bands (OEB). This is a method of classifying substances based on their hazard potential or toxicity, particularly in relation to inhalation exposure. OEBs are usually classified on a scale of 1 to 5, with OEB 1 representing substances with the lowest hazard potential and OEB 5 representing substances with the highest hazard potential. The OEB bands are not standardized, but are defined by companies themselves. So, there can be deviations, which is important for external employees who deal with containment areas of different companies. OEBs should actually be better called iOEBs, for internal Occupational Exposure Bands.

In practice, by specifying the OEBs, a quick and simple classification is possible, which is immediately understandable for the employees. This is safer than, for example, specifying 10-100 µg/m3 when a new product comes into the company and protective measures are explained. "We are receiving an OEB 4 product" is easier than a '1-10 µg/m3 product'.

What does OEL mean?

Occupational Exposure Limits (OEL) are quantified limit values for the permissible exposure of employees to hazardous substances during their work. These limits are usually expressed in ppm or µg/m3 or mg/m3 and are based on the toxic data of the substance and the current state of knowledge about possible health effects. OELs are set by various organizations and authorities, such as the American Conference of Governmental Industrial Hygienists (ACGIH), the European Medicines Agency (EMA) or the Occupational Safety and Health Administration (OSHA).

Differences between OEB and OEL

Although OEBs and OELs are both used to control employee exposure to hazardous substances, there are important differences:

• Classification vs. quantification: OEBs classify substances according to their hazard potential, while OELs set quantified exposure limits. 
• Subjectivity vs. objectivity: The classification of a substance according to an OEB can be more subjective and based on a comprehensive assessment of various factors, whereas an OEL is based on objective scientific data and threshold values. 
• Scope: OEBs are often used to assess the risk of exposures at early stages of development or when information is limited, while OELs serve as specific guidelines to meet exposure limits in practice.

Example

Here is an example to illustrate this: a new active substance in development is provisionally classified as OEB 4 based on limited toxicological data, indicating a high hazard potential and the associated protective measures. Based on subsequent studies and analysis, an OEL of 1 ppm is set to limit employee exposure based on the specific toxicity data.

So, while OEBs classify substances according to their hazard potential in bands or areas, OELs set quantified limits for the permissible exposure of employees. Both concepts complement each other and are crucial to ensure the health and safety of employees through adequate exposure control.