Document oL5n87G5NLnpbxvy9yqB25wE

able where a vendor comes into the plant with a trailer completely equipped and stocked to fit and sell safety shoes These shoes are normally offered at an industrial price It is difficult to determine when manage ment should pay the cost of personal pro tective equipment and when workers should Factors are the probability and expected severity of injury, the willingness of work ers to wear the equipment, its length of life, and the degree to which it may be depreci ated by nonoccupational use For example, the welder's helmet is almost universally supplied by management, for the job could not be performed at all without it Work gloves sometimes must be purchased by the user On the other hand, welder's or other special purpose gloves are usually considered as being a necessary part of the job work tools and are issued free No matter what decision is made, it remains management's responsibility to develop and enforce the program This is one of the mam themes in the first eight chapters of this Manual Head Protection Although every worker should be encour aged to use his head to absorb knowledge-- he should not use it to absorb blows Men exposed to head hazards must be provided with head protection Safety hats Safety hats (or helmets) are ngid headgear of varying matenals designed to protect the workman's head--not only from impact but from flying particles and electric shock or any combination of the three Helmets (see Fig 38-2) have been classi fied into two types (a) full bnmmed, and (b) brimless with peak The types have been further broken down into four classes Class A, limited voltage resistance for general ser vice, Class B, high voltage resistance, Class C, no voltage protection (metallic helmets). Class D, limited protection for fire fighters service All helmets that meet American Standards Z89, Standard for Industrial Protective Hel met, shall be identified on the inside of the helmet shell with the manufacturer's name, American Standard designation, and class (A, B, C, or D) Matenals used m the construction of Class A and B helmet shells should be water re sistant and slow burning Matenals m Class D helmets shall be fire resistant (self-exbnguishing when tested m accordance with ASTM Standard D-635), and nonconductors of electncity Class B (utility service) headgear do not have holes in the shell or any metal parts at all The headpieces designed for use around electrical hazards meet voltage tests of20,000 volts AC (rms), 60 cps, for three minutes and leakage currents not exceeding nine ma The other classes have a less stnct require ment 2200 volts AC (rms), at 60 cps for one minute with no more than 9 milhamperes leakage The breakdown threshold for all helmets is the same 30,000 volts The thinnest section of Class A and B hel met shells will not bum at a rate greater than 3 m per minute After a 24-hr immersion test, water absorption of the shell will be no more than 5 0 per cent (by weight) for Classes A and D, and 0 5 per cent for Class B All helmets are designed to transmit a maximum average force of not more than 850 lb when tested m accordance with Ameri can Standard 89 No individual helmet shall transmit a force of more than 1000 lb When used properly, these hats will greatly reduce injury from falling objects as well as exposure to electric bums See Edison Elec tric Institute publication AP-1-1961, Speci fications for Electrical Workers lnsulattng Safety Headgear Metal helmets do not afford the high impact resistance of plastic ones, but because of their lighter weight, they are preferred by some workers Metal helmets should never be used where electrical hazards or substances corrosive to aluminum are present (see Amer ican Standard Z89) Weight and shape of hat American Stand ard Z89 specifies the weight for Class A and C helmets shall not exceed 15 oz, including suspension but excluding winter liner and chin strap Class B helmets can go as heavy as 15Vi oz A bnm all around the helmet (Fig 38-2d) provides the most complete protection for 1145