2 
CODE FOR IDENTIFICATION OF GAS-MASK CANISTERS 
DEFINITIONS 
Gas mask, 
6. The words “gas mask” as used shall be understood to mean a 
device designed and constructed so that all air is excluded from the 
respiratory system of the wearer except that which is drawn through 
a canister forming a part of the gas mask. 
Canister, 
7. The word “canister” as used shall be understood to mean a 
container in which there are filtering, absorbing, adsorbing, neutral- 
zing, or catalyzing materials capable of affording protection against 
harmful gases, vapors, smokes, and mists, singly or in combination, 
also dust in combination with any of these when used in connection 
vith, or as part of, a gas mask. 
COLORS 
8. Each gas-mask canister shall be given a distinctive color in 
accordance with the following: 
3ases, vapors, smokes, or mists to be protected 
against 
A. Acid. __ = 
B. Organic vapor. . J 
C. Ammonia... couce  aunoo. 
J. Carbon monoxide. ......_... 
E. Acid and organic vapors._.._ 
F. Acid and organic vapors and 
ammonia. 
G. Dusts, smokes, mists in com- 
bination with any of the 
above gases. 
H. All of the above gases..__.. 
Red. Filters are included in this 
canister, but stripes to indicate 
them are unnecessary. 
I. Other special gases. .____... | Color to be assigned. 
Nore.—This code was formulated through the cooperation of the National 
Safety Council, United States Bureau of Mines, and American Standards Asso- 
dation. These agencies will be glad to consider requests for additional color 
1ssigniments for other possible gases or combinations if such gases assume impor- 
bance in industry. 
9. All colors used shall be such as to be clearly identified by the 
user and clearly distinguishable one from another. When more than 
one color is used there shall be a decided contrast between them. 
10. The color coatings used shall offer a high degree of resistance to 
:hipping, scaling, peeling, blistering, fading, and to the effects of 
chemical fumes, smokes, gases, moisture, and dusts in the ordinary 
atmospheres to which they may be exposed under normal conditions of 
storage and usage.