Exposure Limits; Mixtures Of Contaminants; Exposure Limits For Mixtures - MSA G1 Operating Manual

US
5.2

Exposure Limits

Refer to the applicable exposure limits from the following sources:
• American Conference of Governmental Industrial Hygienists (ACGIH)
• Occupational Safety and Health Administration (OSHA)
• National Institute for Occupational Safety and Health (NIOSH)
• American Industrial Hygiene Association (AIHA)
Contact MSA at 1-800-MSA-2222 for information.
5.3

Mixtures of Contaminants

WARNING!
If any one contaminant in a mixture is the same as or more than the IDLH concentration, the entire mixture is IDLH. Do NOT
use the respirator, except for escape when the respirator is used in a gas mask configuration.
Failure to follow this warning can result in serious personal injury or death.
NIOSH approves of mixing the following contaminants: organic vapors, chlorine, chloride dioxide, hydrogen sulfide, sulfur
dioxide, ammonia, and carbon monoxide.
Particulates can be mixed with any other particulate or any gas or vapor for which the air filtration cartridges/canisters are
approved.
This respirator can be used for protection against a mixture of contaminants in an environment at the same time or against one
contaminant then another (using the same air filtration cartridges/canisters) ONLY in the following conditions:
• The air filtration cartridges/canisters are approved for all contaminants in the environment.
• Contaminants in the environment at the same time are less than the IDLH levels for the specific contaminants.
5.4

Exposure Limits for Mixtures

ACGIH publishes the following information to calculate the threshold limit value (TLV) of a mixture:
First, use the following formula to calculate the total concentration of the chemical mixture (C
contaminant concentrations (C1, C2, C3...):
(C ) = C1+C2+C3...
Mixture
Use the following formula to calculate the TLV of the mixture, where T1, T2, T3, ... are the individual contaminant TLVs and
C1, C2, C3... are the individual contaminant concentrations:
T = C
Mixture Mixture
C + C
1 2
T T
1 2
Use these equations ONLY if the contaminants in the environment are actually mixed. Some substances do not mix and may
be in the environment separately, for example, in pockets or at different levels. In that case, use the lowest TLV of the
substances in the environment to find the applicable respirator category for protection against all contaminants in the
environment.
17
+ C
+ ....
3
T
3
G1 APR Facepiece
5 Before Use
) from the individual
Mixture