19
Before Use
G1 Air-Purifying Respirator (APR)
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 obey this warning can result in serious injury or death.
NIOSH approves of mixing the following contaminants: organic vapors, chlorine, chloride dioxide,
hydrogen sulfide, acid gases, ammonia, and carbon monoxide.
Particulates can be mixed with any other particulate or any gas or vapor for which the air filtration
cartridge(s)/canister 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 cartridge(s)/canister)
ONLY in the following conditions:
• The air filtration cartridge(s)/canister 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
Mixture
)
from the individual contaminant concentrations (C1, C2, C3...):
(C
Mixture
) = C1+C2+C3…
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:
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 appli-
cable respirator category for protection against all contaminants in the environment.
T
Mixture
=
C
Mixture
C
1
+ C
2
+ C
3
+ ....
T
1
T
2
T
3
