Electrical hazards protection against

FPN No. 1) It is important that the authority having Jurisdiction be familiar with recorded industrial experience as well as with standards of the National Fire Protection Association, the American Petroleum Institute, and the Instrument Society of America that may be of use in the classification of various locations, the determination of adequate ventilation, and the protection against static electricity and lightning hazards. 

The reaction of Lead Azide (LA) with Cu (see Table) deserves special comment, Although this reaction is relatively slow, even in the presence of w, some forms of Cu Azide are so sensitive that they create a serious hazard even in minute quantities, particularly when in contact with LA. For this reason, AJ and stainless steel containers are now used exclusively. PicArsn requires that all new fuze designs contain no Cu or Cu alloys, with the possible exception of the electrical system. Even here, the Cu must be coated for protection against the formation of hydrazoic acid. Another prohibition involves the use of Pb thiocyante in contact with A1 (Refs 4, 5 6)... 

In areas where dry powder is handled, the buildup of static electricity presents a safety hazard. A static charge could possibly ignite or detonate propellant in the dry state. For this reason, materials used in these areas are conductive and properly grounded. Flooring and footwear must also be conductive as outlined in the Department of Defense Safety Manual. Conductivity tests are made periodically to insure that there is proper protection against static charge buildup. 

Retention of a required level of electrical Insulation to protect against electrical breakdown, arcing, etc., with the associated dangers and hazards of electrical fires, and human safety. 

Street shoes may not be appropriate in the laboratory, where both chemical and mechanical hazards may exist. Substantial shoes should be worn in areas where hazardous chemicals are in use or mechanical work is being done. Clogs, perforated shoes, sandals, and cloth shoes do not provide protection against spilled chemicals. In many cases, safety shoes are advisable. Shoe covers may be required for work with especially hazardous materials. Shoes with conductive soles are useful to prevent buildup of static charge, and insulated soles can protect against electrical shock. 

The pH meters used for continuous industrial measurement commonly have a standard 4-20 mA output. The amplifier unit will usually drive a separate display element remote from the measurement point. The pH electrode needs to be close to the amplifier since the electrode has very high impedance and hence requires short leads and careful screening. The amplifier will need to be protected against its environment and also the environment will need to be protected from the electrical hazard posed by the amplifier. Suitable intrinsically safe pH amplifier systems can be obtained commercially. Only the electrodes and the amplifier need to be located in the hazardous area where the measurement is taking place whereas the other equipment and display element can be located in a safe area. 

Refer to 29 CFR 1910.135 for information about OSHA head protection. Ensure workers wear appropriate head protection that can resist penetration and absorb the shock of blows. Evaluate the need for using protective hats to protect against electric shock. OSHA requires head protection hats to meet the requirement of ANSI Z-89.1, Industrial Head Protection, and Z-89.2, Requiranents for Industrial Protective Helmets for Electrical Workers. Each type and class of head protector must provide protection against specific hazardous conditions. An understanding of these conditions will help in selecting the right hat for the particular situation. 

OSHA has proposed 71,000 in fines against a contractor performing demolition work for failure to protect employees from electrical hazards. 

Electrical hazard shoes — Offer protection against shock hazards from contact with exposed circuits. 

Sturdy safety shoes should have impact-resistant toes and heat-resistant soles to protect against hot work surfaces common in roofing, paving, and hot metal industries. The metal insoles of some safety shoes protect against puncture wounds. Safety shoes may also be designed to be electrically conductive to prevent the buildup of static electricity in areas with the potential for explosive atmospheres, or noncon-ductive to protect workers from workplace electrical hazards. All safety shoes must comply with the ANSI standard(s) mentioned above. In addition, depending on the types of worker exposures, there may be a need to provide specially designed safety shoes such as conductive or electrical-hazard safety shoes. 

Electrical hazard, safety-toe shoes are nonconductive and will prevent employees feet from completing an electrical circuit to the ground. They can protect employees against open circuits of up to 600 volts in dry conditions. Electrical hazard, safety-toe shoes should be used in conjunction with other insulating equipment and precautions to reduce or eliminate the potential for employees bodies or parts of their bodies to provide a path for hazardous electrical energy. Note Nonconductive footwear must not be used in explosive or hazardous locations in such locations, electrically conductive shoes are required. Train employees to recognize that the insulating protection of electrical hazard, safety-toe shoes may be compromised if... 

Note to paragraph (d) IEEE Std 80-2000, IEEE Guide for Safety in AC Substation Grounding, contains guidelines for protection against hazardous differences in electric potential. 

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