17
Preparing for Use
G1 Powered Air-Purifying Respirator (PAPR)
US
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.
6
Preparing for Use
WARNING!
Make sure that all respirator components with threads are installed correctly. Cross-threading can
cause a connection to feel tight, but does not supply a sufficient seal for protection.
Failure to obey this warning can result in serious injury or death.
Make sure that the device does not have any of the conditions listed in Section 4 "Visual Examina-
tions".
Make sure that there are no parts missing from the assembled device.
Make sure that the air filtration cartridges/canisters are approved for and effective against all contam-
inants in the environment.
Make sure that the device is in an approved configuration. For information about approved configura-
tions, refer to the G1 PAPR Approval Insert (PN 10192481).
Make sure that the head harness is in an approved configuration.
NOTE:
The rubber neck strap (Model Number 7-2830-1) is not approved for use with the 4-point black
cloth head harness (Model Number 7-3104-1).
Before going into a contaminated area, use the following factors to make an estimate of the maximum
safe duration of use:
• The amount and type of contaminate in the air, and the capacity of the air filtration cartridge/
canister to absorb or neutralize the contaminant. An average airflow of approximately 2 cfm will
flow through each cartridge/canister during extended use.
• The number of airborne particles (dust) in the atmosphere.
• The charge contained in the battery.
• The physiological limits of the respirator user.
T
Mixture
=
C
Mixture
C
1
+ C
2
+ C
3
+ ....
T
1
T
2
T
3