Table 5-6. - OSHA Safety Color Codes OSHA SAFETY COLOR CODES Red Fire protection equipment and apparatus: portable containers of flammable liquids: emergency stop buttons; switches Yellow Caution and for marking physical hazards. waste containers for explosive or combustible materials; caution against starting. using. or moving equipment under repair: identification of the starting point or power source of machinery Orange Purple Green Dangerous parts of machines; safety start buttons; the exposed parts (edges) of pulleys, gears, rollers. cutting devices. and power

jaws Radiation hazards Safety; location of first aid equipment (other than fire fighting equipment)

Figure 5-39. - Technique for taping a solderless connector.

The following list gives the four common types of fire. Each type of fire is designated by a class.

Class A fires occur in wood. clothing, paper, rubbish, and other such items. This type of fire usually can be handled effectively with water. (Symbol: green triangle.)

Class B fires occur with flammable liquids, such as gasoline, fuel oil, lube oil, grease, thinners, paints, and so forth. The agents required for extinguishing this type of fire are those that will dilute or eliminate the air by blanketing the surface of the tire. Foam. CO₂ , and dry chemicals are used. but not water. (Symbol: red square.)

Class C fires occur in electrical equipment and facilities. The extinguishing agent for this type of fire must be a nonconductor of electricity and provide a smothering effect. CO₂ and dry chemical extinguishers may be used, but not water. (Symbol: blue circle.)

Class D fires occur in combustible metals. such as magnesium. potassium. powdered aluminum. zinc. sodium, titanium, zirconium, and lithium. The extinguishing agent for this type of fire must be a dry-powdered compound. The dry-powdered compound must create a smothering effect. (Symbol: yellow star.)

Figure 5-40 shows the symbols that are associated with the four classes. One or more of these symbols should appear on each extinguisher. Because all fire extinguishers cannot be used on all types of fires, the electrician should be aware of how to identify which fire extinguisher should be used.

Always read the operator's instructions before using an extinguisher. Also, never use water against electrical or chemical fires. Water also should not be used against gasoline, fuel, or paint fires, as it may have little effect and only spread the fire. Figure 5-41 shows some common fire extinguishers and their uses.

Fire extinguishers are normally red. If they are not red, they should have a red background so they can be easily located.

If the tire department is called, be ready to direct them to the fire. Also, inform them of any special problems or conditions that exist, such as downed electrical wires or leaks in gas lines.

In this chapter we have discussed various aspects of interior wiring (above and below grade), bending conduit. conduit support and installation. soldering and splicing, and electrical and fire safety. Each of these areas was briefly discussed and reference given to where you could find additional specific information. To understand the material discussed, you must study these references.