Industrial Hygiene

Airflow in the Laboratory

General airflow through the laboratory space is a design element that safety is often asked to comment on.  With the growing awareness of energy conservation for both sustainability efforts and costs savings, labs are being asked “how low can you go” when it comes to air changes per hour (ACH).  The general heating, ventilation and cooling (HVAC) controls for the laboratory space can often be manipulated for efficient air supply that provides both occupant comfort and some degree of safety.  When determining what the proper air flow should be, several factors must be considered in conjunction with ACH.

In offices, a percentage of the air supplied to the space can be recirculated from the same space, which saves on heating and cooling costs.  All laboratory air is single pass, which means that it is 100% supplied fresh air from the outside.  This is good news for lab occupants, as the air circulating in the space is all fresh, but not good news for […]

Exploring Exposure Limits: What do those numbers mean?

If you’ve ever attended safety training, you surely have heard the terms PEL, TLV, REL and STEL.  Do these letters really have a meaning or are they just a bunch of alphabet soup?  These acronyms all represent different occupational exposure limits (OELs) that are derived by different organizations.  An OEL is representative of the highest concentration a healthy worker can be exposed to for a full work week over the duration of their working life without experiencing an adverse effect.  Although similar, they each have a different goal and meaning.

Permissible Exposure Limit (PEL)

The Permissible Exposure Limit, or PEL, is the most widely known exposure limit.  This is the OSHA 8-hour time weighted average (TWA) exposure limit and is the only limit directly enforceable by regulation.  OSHA limits must be approved by Congress and take into account both health benefits and industry costs.  PELs are difficult to change because of the congressional approval required.  These […]

February 5th, 2020|Categories: Insights|Tags: , , , |