MSA FireHawk M7 Responder APR Operation And Instructions Manual page 8

D. MIXTURES OF CONTAMINANTS – This FireHawk M7
Responder APR can be used for protection against a
mixture of contaminants that are present simultane-
ously or alternately against one contaminant then
another (using the same canister) if the mixture meets
the following conditions:
1. The canister must be approved for all contaminants
present.
2. NIOSH permits mixing of the following contami-
nants: organic vapors, chlorine, chloride dioxide,
hydrogen sulfide, acid gases, ammonia, and carbon
monoxide.
3. Particulates can be mixed with any other particulate
or any gas or vapor for which the canister is
approved.
4. Contaminants present simultaneously must be
below IDLH levels for the specific contaminants. If
any one contaminant in the mixture exceeds the
IDLH concentration, then the entire mixture must be
treated as IDLH and the respirator cannot be used.
EXPOSURE LIMITS
A listing of applicable exposure limits from the following
sources is provided in MSA's Response® Respirator
Selector: available online at www.MSAnet.com.
- 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.
TAL 803 (L) Rev. 0 - 10086002
GENERAL DESCRIPTION
EXPOSURE LIMITS FOR MIXTURES
The American Conference of Governmental Industrial
Hygienists (ACGIH) publishes the following information to
determine the Threshold Limit Value (TLV) of a mixture.
First, determine the total concentration of the chemical
mixture (C Mixture ) from the individual contaminant con-
centrations (C 1 , C 2 , C 3 ...) using the following formula:
C Mixture = C 1 +C 2 +C 3 +...
The TLV of the mixture is found by using the following for-
mula where T 1 , T 2 , T 3 , ... are the individual contaminant
TLVs and C 1 , C 2 , C 3 ... are the individual contaminant
concentrations:
Only use these equations if the contaminants present are
actually mixed. Some substances do not mix and may be
present separately, for example, in pockets or at different
levels. In that case, the lowest TLV of the substances pre-
sent must be used to determine the appropriate respirator
category for protection against all contaminants present.
See MSA's Response Respirator Selector for additional
information.
8
C
T
mixture
mixture
C C C
1 2 3
+ +
T T T
1 2 3