You must:
• Make sure employees are protected from potentially hazardous exposure while you perform your evaluation
• Perform your evaluation without considering the protection provided to employees by a respirator
• Determine the form of the hazard, such as dust, mist, gas, oxygen deficiency, or biological agent
• Make sure you consider:
– Potential emergency and rescue situations that may occur, such as equipment or power failures, uncontrolled chemical reactions, fire, explosion, or human error
– Workplace conditions such as work processes, types of material, control methods, work practices and environmental conditions.
• Determine or reasonably estimate whether any employee is or could be exposed to any of the following:
– Any airborne substance above a permissible exposure limit (PEL) listed in Table 3
– A substance at or above the action level (AL) specified in the rule for that substance
– Any other respiratory hazard.
• Use any of the following to determine employee exposure:
– Information that would allow an estimate of the level of employee exposure, such as MSDSs or pesticide labels, observations, measurements or calculations
– Data demonstrating that a particular product, material or activity cannot result in employee exposure at or above the AL or PEL
– Personal air samples that represent an employee's usual or worst case exposure for the entire shift.
Note: | • Rules for specific substances may contain additional requirements for determining employee exposure. |
| • Use methods of sampling and analysis that have been validated by the laboratory performing the analysis. |
| • Samples from a representative group of employees may be used for other employees performing the same work activities when the duration and level of exposure are similar. |
You must:
• Consider the atmosphere to be immediately dangerous to life or health (IDLH) when you cannot determine or reasonably estimate employee exposure
• Make sure employee exposure, to 2 or more substances with additive health effects, is evaluated using this formula:
The symbol | Is the . . . |
E | Equivalent exposure for the mixture. When the value of E is greater than 1, a respiratory hazard is present. |
C | Concentration of a particular substance. |
L | TWA, STEL, or ceiling for that substance from Table 3. |