Section VI. Fire Protection (29 CFR 1910.156)

TM 38-400/NAVSUP PUB 572/AFMAN 23-210 MCO 4450.14/DLAM 4145.12

Portable combustible gas indicating detectors.

(2) If the use of ferrous metal hand tools is

Portable combustible gas indicating detectors available

required because of strength characteristics, the

for use as follows:

immediate area should be free from exposed explosives

and other highly combustible materials except in

(1) For detection of miscellaneous flammable

specific operations approved by the service/ agency

gases (including hydrogen) and vapors.

concerned. Prior to use, all ferrous metal hand tools to

(2) For indication of the concentration of

be used must be examined by the local safety office and

hydrogen in mixtures with air or oxygen.

approved for use.

(3) For detecting combustible gases or

vapors associated with fuel oils, gasoline, and paints.

n. Safety treads. Safety treads should be installed

(4) For detecting concentrations of one or

on ladders, stairs, and floor surfaces to prevent slipping.

more specific combustible gases in mixture with air or

Several types of safety treads are available.

oxygen.

o. Knee pads.

Knee pads will provide for

protection of knees of carpenters, riggers, or mechanics

m. Safety hand tools.

who must kneel while working.

(1) Safety hand tools are constructed of wood

p. Carboy tilter. Carboy tilters will be used for safe

or other nonsparking or spark resistant materials such as

removal of dangerous liquids such as acids from

bronze, lead, beryllium alloys, and "K" Monel metal

carboys.

which, under normal conditions of use, will not produce

q. Special bung fittings and automatic faucets.

sparks. Properly maintained, nonferrous hand tools

Special bung fittings and automatic faucets will be used

shall be used for work in locations which contain

on drums for dispensing and storing of dangerous liquids

exposed explosives or hazardous concentrations of

(ref. NFPA Code 30).

flammable dusts, gases, or vapors. Hand tools or other

r. Special gas fill caps and metal sediment bowls.

implements used in the vicinity of hazardous materials

Special gas fill caps and metal sediment bowls will be

must be handled carefully and kept clean. All tools

used on powered MHE for safety in replenishment of

should be checked out before beginning work and

fuel.

checked in at its completion.

Section VI. Fire Protection (29 CFR 1910.156)

6-13. Classification of fires.

b. The classification and rating system described

a. Class A fires are fires in ordinar y combustible

in this section is that used by Underwriters' Laboratories,

materials such as wood, cloth, paper, and rubber.

Inc. and Underwriters' Laboratories of Canada and is

based on extinguishing preplanned fires of determined

b. Class B fires are fires in flammable liquids,

size and description as follows:

gases, and greases.

(1) Class A rating-wood and excelsior fires

c. Class C fires are fires which involve energized

excluding deep-seated conditions.

electrical

equipment

where

the

electrical

nonconductivity of the extinguishing media is of

(2) Class B rating-2-inch depth gasoline fires

importance.

(When electrical equipment is de-

in square pans.

energized, extinguishers for class A or B fires may be

(3) Class C rating-no fire test. Agent must be

used safely.)

a nonconductor of electricity.

d. Class D fires are fires in combustible metals

(4) Class D rating-special tests on specific

such as magnesium, titanium, zirconium, sodium, and

combustible metal fires.

potassium.

6-15. Classification of hazards.

6-14. Classification of portable extinguishers.

a. A light hazard is a situation where the amount of

a. Portable fire extinguishers are classified for use

combustibles or flammable liquids present is such that

on certain classes of fires and rated for relative

fires of small size may be expected. These may include

extinguishing effectiveness at a temperature of plus

offices, schoolrooms, churches, assembly halls,

70 . by nationally recognized testing laboratories.

telephone exchanges, etc.

This is based upon the preceding classification of fires

b. An ordinary hazard is a situation where the

and the fire extinguishment potentials as determined by

amount of combustibles or flammable liquids present is

fire tests.

such that fires of moderate size may be expected.

6-4