What is WEL?

WEL stands for Workplace Exposure Limit.

Exposure limits are simply the boundaries that are defined for substances that present a threat to human health. Exposure limits vary from substance to substance and are based on the work environment. There are also different types of exposure limits, such as time-weighted exposure values, short-term exposure limits, and ceiling exposure limits. However, they are all designed to ensure that workers do not suffer adverse health effects.

Exposure to a substance is uptake into the body. The exposure routes are:

• By breathing fume, dust, gas, or mist.
• By skin contact.
• By injection into the skin.
• By swallowing.

Many thousands of substances are used at work but only about 500 substances have Workplace Exposure Limits (WELs) listed in EH40 workplace exposure limits.