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RHODt ISLAND LUNG ASSOCIATION Monographs on Occupational Health V, one of a series 1983 WIRE and CABLE MANUFACTURING Toxic Air Contaminants , *''CDE ISLAND LUNG ASSOCIATION I ' 2 7 Wes tries ter y.all, Prcviderc C29C3 n^<v uprr^.^rt a (t.V'tM5 JWJt? I * . TABLE'OF CONTENTS INTRODUCTION . THE WIRE AND CABLE INDUSTRY IN RHODE ISLAND OCCUPATIONAL INJURY AND ILLNESS DATA FOR RHODE ISLAND STUDIES OF WORKER HEALTH . WIRE AND CABLE MANUFACTURING PROCESSES . WIRE DRAWING TINNING AND ELECTROPLATING INSULATION OF HIRE AND CABLE ASBESTOS RUBBER AND PLASTIC COMPOUNDING 1 STRAINING AMD MILLING RUBBER DUSTING RUBBER AND PLASTIC EXTRUSION SPARK TESTING BRAZING MEDICAL MONITORING OF WORKER HEALTH . PAGE 1 1 1 2 3 3 4 5 5 6 14 14 15 16 17 IB POTENTIAL HEALTH HAZARDS IN THE HIRE AHO CABLE INDUSTRY PROCESS AGENT HAZARD Wire Drawing Tinning Electroplating Heavy reels of wire and cable Hoise Lubrl cants Tin Mists of acids and bases Insulation of wire Asbestos and cable with asbestos Insulation of wire and cable with rubber and plastic compounds Dusts and vapors from a variety of chemicals listed on pages 7-15. Stripping of lead Lead cables Rubber dusting Talc Asbestos Mica Zinc Stearate Back injury as the result of lifting or moving heavy reels Hearing Impai rtnent Dermatitis Nondebilitating emphysema Skin irritation and bums Lung Irritation, inflammation, and possibly, bronchitis or permanent lung damage Lung Cancer lung Fibrosis (Asbestosis) Mesotheliomas (cancers on the membranes lining the lungs and abdominal organs) Cancers and damage to various organs including lungs, liver, kidneys, and bladder due to in halation, ingestion or absorp tion of chemicals through the skin. Interference in the formation of red blood cells, anemia, gastrointestinal problems, cen tral nervous system damage Pulmonary Fibrosis... lung Cancer,Asbestosis, Mesotheliomas Pulmonary Fibrosis Pulmonary Fibrosis Spark Testing Brazing Ozone (low concentration) Ozone (high concentration) Brazing fumes from flux materials including fluorides, cadmium, zinc, copper, brass Throat irritation, bronchitis Irreversible lung damage Irritation of skin, eyes, and respiratory tract and possibly cancer Fetal Fume Fever Toxic Air Contaminant Hazards Associated with the Manufacture of Electrical Wire and Cable INTRODUCTION Many potentially hazardous chemicals are used In the manufacture of electrical wire and cable. The vast majority of these chemicals are employed In the production of rubber and plastic Insulating materials. Because such a wide variety of wire and cable products is manufactured, it Is not possible to talk In concrete terms about toxic chemical hazards throughout the industry. Each type of wire Is manufactured to meet specific needs and can require the use of different compounds. Therefore, it is hoped that this report will serve as a general guide to potential air contaminant hazards and their control, as well as a starting point for further shop specific evaluation. v. THE WIRE AND CABLE INDUSTRY IN RHODE ISLAND Rhode Island has one of the highest concentrations of wire and cable firms In the United States. Its 12 firms manufacture a wide variety of wire and cable 'products Including appliance wire, building wire, power transmission wire, under ground cable, power supply cords, extension cords, heater cords, automotive wire, and telephone wire. According to the Bureau of Labor Statistics, In 1980 approximately 5000 workers were enployed In Rhode Islands electrical wire and cable firms, accounting for about of the state's total manufacturing labor force. Most of the firms are unionized with the majority of workers belonging to either the International Brotherhood of Electrical Workers (IBEM) or the United Steel Workers of America (USWA). OCCUPATIONAL INJURY AND ILLNESS CflTA FOR RHODE ISLAND One way to analyze the health status of wire and cable workers Is to look at the Bureau of Labor Statistics' (BLS) occupational injury and Illness data. This Information must be carefully interpreted since it is widely recognized that many illnesses go unreported and are difficult to link to job conditions, while occupational injuries are much more obvious. BLS data is primarily useful in providing a relative comparison of injury rates among Industrial categories. Injury and illness data for 1980 showed that no work related Illnesses were reported in Rhode Island's wire drawing industries. However, the number of workers who lost days due to work-related Injuries was higher than for Rhode Island manufacturing Industries in general, and for wire workers nationwide. In addition, injured workers were out about twice as many days as workers in the same industry nationwide, twice as many days as workers in manufacturing in Rhode Island, and about three times as many days as workers in manufacturing nationwide. Back injuries account for most of the lost time from work in the wire and cable industry. 2 STUDIES OF WORKER HEALTH Very few studies have been conducted on the health of workers in the wire and cable Industry. Those that have been done involved wire and cable firms in England. The major concern in these studies was the effect of exposure to a certain antioxidant contalnlnq alpha and beta naphthylamines used in the produc tion of rubber Insulated wire. Production of the antioxidant ceased in England In 1949. Neither alpha nor beta naphthylamlne has ever been banned in the United States, although there has been no production of beta naphthyl amine In the past 10 years. Alpha naphthylamlne Is still comnercially available. The early British studies revealed that rubber workers in both the rubber and cablemaking Industries who were exposed to the antioxidant were at an in creased risk for contracting and dying from tumors of the bladder. Today, both alpha and beta naphthylamlne are regarded as bladder carcinogens. While few studies have been conducted concerning the health of workers in the wire and cable Industry, many studies have been done on workers In the rub ber industry. In 1970, the United Rubber Workers Union contracted with six U.S. rubber companies to have comprehensive studies done to determine the ad verse health effects of employment In the rubber industry. Since many of the chemicals that are used in the rubber Industry are also used In the wire and cable industry, the results of these studies should be mentioned. Studies conducted on workers in the rubber Industry have shown that these workers experience excess deaths from certain types of cancers and from several other diseases. A review of the literature reveals a wide range of diseases associated with employment in the rubber industry including cancers of the bladder, prostate, cervix, lymphatic system, central nervous system, bowel, and stomach, as well as leukemia, heart disease and stroke. It has been shown that for many of these diseases, workers employed In the rubber processing divisions are at the greatest risk. The processing divisions include rubber compounding, mixing, milling, extrusion, calendaring, cement mixing, and rubberized fabric operations. In general, rubber processing workers are at greatest risk for developing chronic respiratory disease, cancers of the stomach, large intestine, liver and biliary passages, as well as leu kemia. Rubber processing has been further broken down by researchers into front and back processing. A 1932 study showed that the risk for certain diseases is different depending on the division in which a worker is employed. Front processing workers are those who are involved in rubber compounding, mixing, and milling. They are at the greatest risk for cancers of the stomach and large intestine. Back processing v/orkers are involved in extrusion, calendaring, cement mixing, and rubberized fabric operations. They have been found to be at greater risk for leukemia and emphysema. lany of the diseases associated with employment in the rubber industry have long latent periods, meaning that it may take many years after an occupational exposure before a disease develops. For example, the latent period for prostate cancer is about 30 years. It has been determined that workers at the greatest risk for contracting prostate cancer were employed in the rubber industry 3 between 1940 and 1947. Therefore, even though many potentially hazardous chemicals are no longer being used, workers exposed years ago may still be at risk for developing an occupationally-related disease as a result of past exposures. It should also be noted that studies have shown that-SMOKING INCREASES THE RISK OF OCCUPATIONALLY-RELATED LUNG DISEASES. More research is needed to determine which chemicals used in the manu facture of rubber products are the cancer causing agents and whether or not employment In certain departments is actually causal. HIRE AND CABLE MANUFACTURING PROCESSES The following discussion examines the various processes Involved in the manufacture of electrical wire and cable and highlights the major health hazards and methods of control associated v/ith each. WIRE DRAWING In the wire drawing process, metal rods are reduced in diameter by pulling them through a series of industrial dies within a wire drawing machine. Often a series of machines containing dies of decreasing size is required to reduce the rods to wire of a desired thickness. . Rods usually consist of either copper or aluminum, however, alloys of other metals are occassionally used. Copper and aluminum as received at the wire and cable plant present few health hazards. Some sensitive individuals may develop dermatitis (a skin disorder) from handling copper rods, but this condition disappears when the exposure ceases. The wearing of gloves is an effective control measure. ' There appear to be few problems in terms of chemical exposures during the wire drawing process. The only potential problem involves the use of lubricants in the wire drawing machines to facilitate passage of the wire through the dies. Lubricants are supplied in diluted form to each set of dies by pumping action from a central reservoir. It is unlikely, however, that enough of the lubricants would become airborne under normal operating conditions to cause any adverse health effects due to their inhalation. If inhaled in enough quantity, the fatty materials contained in some lubricants could cause lipoid pneumonia. Con tact dermatitis, or skin irritation, is a possibility should the lubricants touch the skin. The wearing of gloves and regularly cleaned work clothing should prevent this problem. HOISE A major hazard involved in wire drawing, although not an air contaminant hazard, is noise. Excessive exposure to noise can cause permanent hearing impairment. Many plants have well over a hundred wire drawing machines which, without any controls, can produce noise levels well over the OSHA standard of SO dBA averaged over an 0 hour day. Noise levels can be reduced by fitting the machines with sound absorbing enclosures, especially around the gear boxes. In addition, metal gears can be replaced with nylon ones* If engineering controls are not sufficient and noise levels still exceed the standard, vrorkers should be provided with some form of effective, yet comfortable, ear protection. It nay be necessary to limit the amount of time each worker spends in noisy areas. Pre-employment, as well as regular audiometric tests (hearing tests) should be performed to determine whether or not workers are experiencing any hearing impairment. Other machines for which these controls minht also be anollcable Include stranders and braiders which twist several strands of wire together to make thicker more pliable wire and cable. BACK USURIES Another major hazard related to the wire drawing processes the possibility of back injury from moving or redirecting heavy spools of wire by hand. Rack injuries account for most of the lost work time associated with employment in the wire and cable industry. Spools often weigh up to 1300 pounds and should be moved by forklift. Forklifts should operate on natural or liquid petroleum gas rather than gasoline or diesel fuel to avoid carbon monoxide build-up inside the plant. Carbon monoxide (CO) reduces the oxygen carrying canacity of the blood affecting the ability to think and perform manual tasks which can increase accidents. Inhalation of enough CO can result in death by asphyxiation. Where spools must be redirected by hand, metal plates can be set into the concrete floor to make It easier for workers to move the spools. In parts of the plant where other heavy objects must be lifted and where forklifts are impractical, overhead mechanical hoists on ceiling tracks can he installed. Hoists that operate by suction can also be employed to lift heavy bags of chemicals. TIHHiriG AMD ELECTROPLATING Before copper wire can be insulated with natural or synthetic rubber, it is usually necessary to apply a separator between the wire and the insulation. Examples of separators include cotton, paper, and tin. The separator serves several purposes. It prevents the sulfur vulcanizinq agent and other sulfur additives from tarnishing the copper and the cooper from deteriorating the rubber insulation. The tin separator also facilitates subseouent soldering of the wire. . There are two methods of applying the tin separator on the wire; the "hot dip method, and electroplating. "HOT DIP" OR TKmiUG _ . .TMe "hot dip" method requires passing the wire through a bath containing 1 iquid flux and then through a bath of molten tin. Since the flux'is not heated, u re uS chance for it to become an air contaminant hazard. The tin, on the other hand, is heated enough to cause it to melt. While tin is not very toxic, the( inhalation of tin fumes nay cause the development of stannosis, usually a harmless accumulation of tin in the luno tissue. It is only rarely associated with localized ennhysema, a non-debilitating destruction of air sacs. 5 Despite the lack of serious disease threat, local exhaust ventilation over the tin bath is recommended. Enclosing the bath with a hinged canope hood Is the preferred method. This method also reduces energy costs by preventing heat from the bath from escaping Into the workplace and makes the work environ ment more thermally comfortable. Personal protective equipment should include face shield or goggles, leather apron, and leather boots to prevent the molten tin from coming In con tact with the workers* eyes and skin. Electroplating In the electroplating process, wire Is pulled through a series of chemical baths. Basic (or alkaline) and acid baths containing such potentially toxic compounds as sodium hydroxide, sulfuric acid, and hydrochloric acid, serve to clean the wire before It passes Into the electroplating tank., Inorganic tin compounds Including sodiun stannate, stannous chloride, and stannous fluoride present in the electroplating tank provide the source of tin used to coat the wire. Since all of the tanks are heated, fine airborne mists of acids, bases, and inorganic tin compounds are generated at their surfaces. Acids and bases are mucous membrane Irritants affecting lungs as well as eyes. They may also cause skin Irritation and burns. A major danger from repeated Inhalation of these chemicals Is Inflammation of the delicate lung tissue that can, In time, lead to bronchitis or permanent irreversible lung tissue damage. Inorganic tin compounds have not been found to cause systemic effects from occupational exposures, however, some can cause skin and eye Irritation. This Is primarily due to the production of acids and bases upon their reaction with water. Stannous chloride and water, for example, results in the formation of a strong acid, while sodium stannate and water results in the formation of a strong base. ' # Therefore, heated cleaning and electroplating tanks should be equipped with local exhaust ventilation. The use of antifoaming agents and surfactants can be used to reduce misting. In addition to adequate ventilation, the worker should be provided with a face shield or goggles, rubber gloves, rubber apron, rubber boots, and regularly cleaned work clothing in order to avoid any contact with the chemicals. Showering after each work shift is strongly recommended. INSULATION OF MIRE AMD CABLE Hire and cable products are insulated with one of three types of materials: asbestos, rubber, and plastic. ASBESTOS Asbestos is the fibrous form of certain silicates. Uhile not used quite as extensively now as in the past, it is still used by several firms as an in sulating material for wire and cable products due to its noncombustible pro perties. Asbestos may also be found as a contaminant in some types of talc, a rubber dusting agent. 6 It cannot be emphasized enough that asbestos 1$ a definite health hazard. In every major study of asbestos workers, exposure to asbestos, regardless of type, has produced excess mortality from lung cancer. The risk for lung cancer Is the greatest among asbestos workers who smoke and appears to occur 10 to 20 years after the first exposure, peaking at about 30 years. Exposure to asbestos has also been shown to cause asbestosls (lung fibrosis) as well as cancers on the membrane lining the lung (pleura) and abdominal organs (peritoneum) known as mesotheliomas. Symptoms of asbestosls Include shortness of breath and some chest pain. A complete exposure history together with pulmonary function tests and a chest x-ray are required for diagnosis. The control of worker exposure to asbestos Is extremely Important since reducing the exposure reduces the risk of developing an asbestos-related disease. Control of asbestos exposure should be aimed at the prevention of dust dispersion and Include the enclosure of storage, weighing, and mixing pperatlons. local exhaust ventilation should be provided wherever asbestos may escape Into the workplace. The use of face masks or air supplied respirators Is recommended for high level exposures of short duration. Whenever asbestos Is used, regular monitoring of dust levels should be done. . OEFINITIOHS OF RUBBER MID PLASTIC MATERIALS Rubber and plastic materials consist of natural and synthetic polymers which are organic compourdsof high molecular weight made up of simpler molecules, or monomers, bonded together. Both rubber and plastic compounds are tech nically considered plastic materials. Rubber is a thermosetting type of plastic material, while '`traditional" plastics are thermoplastic materials. Thermo setting materials require heat in order to be formed Into a permanent shape and may not be reshaped. Thermoplastics also require heat in order to be formed Into shape, however, they may be resoftened and reshaped if heated again. RUBBER AND PLASTIC COMPOUNDING 8efore wire and cable products can be insulated with rubber and plastic compounds, many potentially toxic chemicals must be added to these basic com pounds in order to make them more suitable as insulating materials. Most of these chemicals are in fine powder form and can present health hazards from in halation or ingestion. Many of these compounds have been shown to cause adverse health effects in cluding Irritation of eyes, respiratory tract, and skin, damage to lungs, liver, and kidneys, as well as cancers of various organ systems. ^ The processes of rubber and plastic compounding require that chemicals which are stored in bags, drums, and bins, be weighed, transferred, and dumped into large mixing machines. In the case of rubber compounding, the mixing machines are known as banburies. Plastic compounding is done in various types of equipment including plasti ficators. Many Rhode Island firms engaged in plastic insulating purchase premixed compounds from custom mixers, however, a few of the larger firms mix their own compounds. 7 Two opportunities exist for exposure to toxic chemicals during rubber and plastic compound mixing: 1) during the initial hand transfer of chemicals from storage containers to bins where they are weighed, and ?.) when the contents of the bins are dumped into the top of the mixers. Since weighing and dumping operations are quite dusty, weighing stations and mixing machines should have local exhaust ventilation. If particularly toxic chemicals must he scooped from bags or drums, workers should also v/ear the appropriate type of respirator. The most effective way of reducing chemical exposures during rubber and plastic compounding operations Is to pump chemicals directly from their storage containers into the mixing machines. In cases where this Is not possible, conveyor systems which automatically dump chemicals into mixers Is preferred over hand dumping. In addition to engineering controls and the use of personal protective equipment like respirators, gloves, and aprons, a good way to minimize dust inhalation is to purchase and use additives In slab or oil-wetted form whenever available. - Decause of the wide variety of toxic exposures during compounding, THERE SHOULD BE NO EATING OR SMOKING IN HORK AREAS. Clean work clothing should be used regularly, and showering before changing into street clothes is strongly recommended. listed below are examples of chemicals used within the wire and cable industry which fall into the various categories of rubber and plastic polymers and additives. Beside each chemical name is a short summary of its potential health effects. This list Is by no means exhaustive, but it is hoped that it will be helpful in itself, and as a start for anyone wishing to further research health hazards associated with rubber and plastic compounding chemicals. RUBBER. POLYMERS A*!t? ADDITIVES Most rubber enters the wire and cable plant in neutral colored bales, some of it natural rubber, and some synthetic polymers such as acrylonitrile-butadiene, ethylene-propylene, and styrene-butadiene; polychloroprene or Neoprene and Hypalon (R) arrive in bags in the form of chips. Many rubber monomers, including chloroprene and acrylonitrile are considered to be hazardous to human health and are regulated by CSHA. Since only the polymeric form of rubber compounds are used in the wire and cable industry and only trace amounts of monomer should remain, health hazards from rubber polymers are thought to be minimal. Residual monomer has been monitored in several firms and not found to be a problem. Still, more research is needed on the health effects of rubber polymers. _ Before rubber can be used as an insulating material, it nust be mixed with a variety of chemicals including fillers, pigments, accelerators, antioxi dants and vulcanizing agents. ' 8 FILLERS Fillers are Inert mineral powders which are added to rubber and plastic mixtures to provide stiffness and hardness. They also serve as extenders which help decrease costs. The following are the fillers used most frequently in the wire and cable Industry. Carbon Black - The health effects of carbon black are controversial. Some authorities regard It as a non-toxic nuisance dust, however, others believe it may cause transient and permanent lung damage, heart problems, and skin irrita tion. It has been shown that workers manufacturing the substance experienced excess lung fibrosis, a hardening of the lung tissue. Certain types of carbon black contain cancer causing polycyclic hydrocarbons which are adsorbed onto it during manufacture. Laboratory animal studies have demonstrated excess cancer from exposure. Human cancer studies are Inconclusive. With multiple chemical exposures often the case. It Is difficult to determine whether or not carbon black Is the causative agent. N1CSK recommends wearing full body clothing including gloves, shoes and goggles when handling the material. Calcium Carbonate (whiting) - Calcium carbonate itself Is non-toxic, however, it is often treated with chemicals whose composition Is not known. Clay - Depending on the geological origin of the clay, it may contain crystalline silica. Crystalline silica refers to silica whose molecules are In a fixed pattern as opposed to a random arrangementdefined as amorphous silica. The inhalation of silica can cause silicosis, a fibrous hardening of the lung tissue which Is often debilitating and sometimes fat 1. Diatomaceous Earth - Diatomaceous earth, like clay, may also contain crystalline silica, and therefore, cause silicosis. The specific type of diatomaceous earth used by wire and cable firms should be evaluated for its crystalline silica content. Lead Oxides - Exposure to lead is one of the more serious hazards associated with wire and cable manufacture. Lead is quite toxic. It can be ingested from con taminated hands, or if heated, inhaled as fumes. Lead is eliminated from the body slowly so even small doses over time can build to toxic levels. The main effect of lead is to Interfere with the formation of red blood cells that carry oxygen to the tissues, resulting in anemia, fatigue, and gastrointestinal problems. High body concentrations can cause nerve damage. Magnesiurn Oxide - Magnesium oxide is a white powder and considered to be a non-toxic nuisance dust. However, high concentrations can cause the lungs* defense mechanisms to become overloaded. The inhalation of newly generated magnesium oxide fumes upon heating can cause metal fume fever and associated blood disorders. Metal Fume Fever is characterized by sudden onset of thirst, a metallic taste in the mouth, high fever, sweating, muscular aches, headache and general feeling of weakness. Symptoms may be delayed for 10 to 12 hours after exposure and are usually worst on days following time away from work, for example, on Monday after a nonworking weekend. Metal fume fever is not a chronic disease. All symptoms subside within 24 to 36 hours after onset. There are no specific tests to detect it and no treatment is known. Other oxides which cause metal fume fever include 2inc, copper, and in some cases, cadmium, iron, tin, manganese, nickel, selenium, and antimony. . 9 Silica - Most of the silica used In rubber Is amorphous rather than crystalline and is regarded as a non-toxic nuisance dust. However, the specific type of silica should be determined for each shop because crystalline silica can cause silicosis, a fibrous hardening of the lung tissue. Zinc Oxide - There appear to be few hazards from zinc oxide dust Inhalation. In rare cases zinc oxide has caused eczema, a crackinn and scaling of the skin. If heate&.zlnc oxide fumes may lead to metal fume fever described above. PIGHEHTS AND COLORADTS Azo Dyes - Many azo dyes have been found to cause cancer of the liver and bladder in animals. Benzidine Based Pigments - Benzidine Is a recognized carcinogen and has been linked to bladder cancer In humans as well as liver, bladder', and colon cancer in rats. It may enter the body as the result of inhalation,Mngestlon, or ab sorption through the skin. Benzidine based pigments may contain significant amounts of residual benzidine. They may also release benzidine when metabolized in the body. OSHA and HIOSH have reconroended discontinued use of these dyes or at least reduction of exposure to the lowest possible levels where discontinued use Is not practical. The use of liquids, pastes, and oil-wetted forms of the dyes are preferable to powdered forms to reduce inhalation of dusts. Good ventila tion should be provided whenever these dyes are in use. Cadmium Compounds - Cadmium compounds are recognized cardnoqefls and have been reported as causing an increased incidence of prostate cancer in men. In addition, they may cause irritation of lungs, coughing, chest pains, sweating, chills and weakness. Long term exposures may result in destruction of lung tissue characteristic of emphysema as well as damage to liver and kidneys. Chromates - Certain chromium compounds, including lead chromate and zinc chromate, are regarded as cancer causing agents. They may also cause skin disorders as well as liver and kidney damage. j-Md Based Pigments - Examples of lead based pigments include yellow and oranae pigments. See page 8 under Lead Oxides for further discussion of lead's hazards. Perylene - Perylene is highly toxic and a suspected carcinogen. Titanium Dioxide - Titanium dioxide is a mild irritant that can cause slight fibrosis (hardening) of the lung tissue without disabling injury. Potential hazards of pigment use to workers can be reduced by the use of "color masterbatches", consisting of physical mixtures of a base rubber, oil, or wax with therequired pigment. The additional cost of these nasterbatches is often justified by the cleaner environment that results from their use. Adequate ventilation, gloves, and protective clothing should be provided and goodpersonal hygiene observed when handling pigments to avoid their inhala tion or ingestion on contaminated hands or smoking materials. 10 ACCELERATORS Accelerators, which are usually organic compounds, reduce the time necessary for the vulcanization or curing of natural or synthetic rubber while Improving aging and other physical properties. Diphenyl Guanidine (DPG) - Animal experiments suggest this accelerator is toxic, but effects on humans are unknown. Ethylene Thiourea (ETU) - This commonly used accelerator for Neoprene compounds has been the subject of considerable Investigation as an industrial cancer risk. Studies have shown It causes cancer and birth defects in laboratory animals. The powdered chemical is no longer distributed for rubber use, but It Is still marketed as a "wetted powder" (oil-treated) and also in combination with rubber materials forming a putty-like substance. The latter form would appear to be the safer of the two, reducing both the chance of Inhalation and ingestion of ETU. Marcaptobenzothlazole (CAPTAX, KBT) - This commonly used accelerator has a very offensive odor. Is a rat poison, and may also cause nausea and.'headaches. It is particularly Irritating to the eyes and may also cause skin irritation and sensitization. Pentaerythritol (PE-200) - This Hypalon accelerator is considered to be a nuisance dust of low toxicity. Elemental Tellerlum (TELLOY) - Elemental tellerium is an accelerator and vulcani zing agent. It is of relatively low toxicity, but may cause a garlic-like odor to the breath, drowsiness, and loss of apetite. __Tetramethyl Thiuram Disulfide (Tl'.TD, THIRAtt, THIURAD, TUEX, ttETHYL TUADS) - This chemical is an irritant to eyes and skin. Dermatitis in the form of eczema, has occurred on hands, forearms, and feet of exposed workers. Tf-TD is closely related to Antabuse, a drug used to establish a conditioned reflex of a fear of alcohol In the treatment of alcoholics, and therefore, may cause an adverse reaction upon consumption of alcohol. The skin reaction portion of this reflex has been ob served in rubber workers who were exposed to TMTD after drinking alcoholic bever ages. Further hazards such as liver, kidney, and brain damage have been reported in experimental animals, but not confirmed in humans. In addition 7T1TD has been found to cause chromosomal damage in several biological systems. It may also adversely affect the activity of certain prescription drugs. letrgjnethyl Ihjuram Monosulfide (MOMEX, UNADS) - Like T!*TD, Monex is an irritant to eyes and skin. It may cause an adverse reaction with consumption of alcohol and affect the activity of certain prescription drugs. It has also been found to cause chromosomal damage In bacteria, but not in mouse lymphoma cells. Tetraethyl Thjuram Disulfide (ETHYL TUADS, ETHYL TUEX) - Ethyl Tuex is irritating to eyes, nose, throat and skin. Like TMTD and Nonex, it may cause adverse re actions with alcohol and some prescription drugs. A National Cancer Institute study concluded that it is not carcinogenic, but that it enhances the carcino genicity of ethylene dibromide. Therefore, the two chemicals should not be used at the same time. 2inc Dimethyldithiocarbanate (ZIRAtf, VAHCIDE) - This accelerator is irritating to eyes, nose, and throat. It has also caused cancer in mice and rats. Other accelerators which may be irritating to eyes and skin include benzotniazyl disulfide, N-tert-butyl-z-benzothia2ole sulfenamide, and butyraldehyde (VA.h'AX). 11 ANTIOXIDANTS Antioxidants are organic compounds added to rubber to slow Its deterioration and retard the aging process. Nickel Di-N-Butyldithiocarbamate (NBC) - This antioxidant is very toxic and a recognized carcinogen. Alpha-Naphthyl amine - This antioxidant is considered to be a',0|*} ^nt0 cause urinary bladtfer cancer. It is readily absorbed Into the body t. ,1oha. and through inhalation. Researchers have had difficulty determining whether alpha naphthyl amine alone or Its beta Impurities are responsible for the bladder cancers. Beta-Haphthvl amine (BNA) - Beta-naphthyl amine is a recognized bladder carc'fn9en and like alpha-naphthyl amine, it Is readily absorbed through the skin and by in halation. There has been no production of beta-naphthylamlne In the U.S. In t e past 10 years, and It was banned In England in 1949. The use of beta-naphthyla. was widespread In both the U.S. and England in the 1940 s. ` Phenyl-Beta-Naphthylamlne (PBNA, NEOZONE D, AGERITE POWDER) - This developed in the IMfl's to replace beta-naphthylamlne after studies linked It to bladder cancer. Commercial PBNA is not only contaminated with BNA, but in tne body, PBNA is metabolized to BNA. There have been no studies linking PB,\A to cancer in humans, but one mouse study showed an increased incidence of nver ... tumors, and another found increased incidence of all tumors. In 1973, 4.9 million pounds of PBNA were produced in the U.S. Currently there is little or no com mercial production. Workers who have been exposed to any of the naphthyl amine antioxidants should have regular cytologic examinations of the urine performed in order to detect early signs of bladder cancer. ADDITIONAL CHEMICALS USED 111 THE MANUFACTURE OF RUBBER INSULATING MATERIALS, Antimony Trioxide - Antimony trioxide is used as a flame retardant and is a fairly powerful irritant of eyes, respiratory tract, and skin. It causes a type of derma titis known as "antimony spots" characterized by intense itching followed by skin eruptions. Antimony trioxide is also a suspected carcinogen. Organic Peroxides - These chemicals are used as crosslinking agents for some types of rubber. They can cause skin irritation and burns as well as severe eye damage. Organic peroxides tend to be unstable and fires or explosions can result from improper storage and handling. Many of these hazards can be minimized by using them in diluted form, such as 40% strength mixtures with clay. Solvents - Solvents are used in certain auxiliary wire and cable processes, for example, coating operations, bonding of rubber insulating materials to wire and cable, special cord set operations, assembly and harness work. A wide variety of solvents are used including printing ink thinner (consisting of methyl ethyl ketone (i'lEK) and cyclohexanone), also xylene, toluene, and acetone which are of low toxicity. Effects of solvent exposure include headache, dizziness, drying of the skin, and eye irritation. Areas where solvents are used should be well ventilated and 12 the processes should be enclosed if possible. Workers should be provided with such personal protective equipment as goggles or glasses, gloves, and respirators for high exposures of short duration. Stearic Acid - Stearic acid Is an accelerator or activator used in rubber com pounding. It Is a white amorphous solid of slight toxicity. Sulfur - Sulfur is a vulcanizing agent and Is of low toxicity. If heated sufficiently It will emit irritating sulfur oxide fumes. PLASTIC POLYMERS AND ADDITIVES The most commonly used plastic polymers In the wire and cable industry are polyvinyl chloride (PVC), polyethylene, polypropylene, and nylon. Polyvinyl Chloride (PVC) - PVC resin Is used as the basis of vinyl compounds and has been "the subject of considerable investigation. It is produced through the polymerization of vinyl chloride monomer (VCM), a gas. In 1974, VCM was found to cause a rare form of liver cancer known as angiosarcoma in workers exposed to high concentrations. Subsequently, it was shown to cause cancer in animals as well. While industry has made tremendous strides in reducing the amount of residual VCM In PVC resins, some still remains. VCM may be released from PVC In storage and more rapidly when It is heated. Therefore, PVC should be stored and handled in v/ell ventilated areas. Whenever PVC is heated sufficiently to cause mass melting, OSHA regulations require that the workplace be monitored for ambient concentrations of VCM to ensure they are in keeping with OSHA standards. Various limits have been proposed for the residual VCM in the resin. Warning labels stating that PVC contains residual VCM, a cancer suspect agent, must be affixed to each package of PVC resin, and it is reconmended that resin users re quest a statement of the analysis of residual VCM from each prospective resin supplier. One of the greatest hazards associated with PVC, as with other plastic compounds, occurs when it Is heated. When plastics, in general, are heated to sufficiently high temperatures, they emit potentially hazardous combustible and noncombustible gases as well as particulates. If plastics are burned, they can create a toxic atmosphere of carbon monoxide and fumes of other plastic decomposi tion products. These products differ depending on the type of plastic. . For most plastics, the temperature at which decomposition products are released is v/ell above the softening temperature-the normal operating temerature for the production of plastic insulated wire and cable. This is true of polyethylene, polypropylene, and nylon. Decomposition products of these plastics include carbon monoxide, carbon dioxide, and water. The exception is PVC. Hydrogen chloride gas (HC1) begins to be released from PVC at normal operating tempera tures of about 300-350'F. Appreciable amounts of HC1 are released upwards of 375F. The major effects of acute exposure to MCI are usually limited to irritation of the upper respiratory tract and are sufficiently severe to warrant prompt withdrawal of persons from the area. Exposure to the gas immediately causes cough ing, burning of the throat, and a choking sensation. Above 650'F, plasticized PVC 13 may release other decomposition products Including carbon monoxide, carbon di oxide, ethane, ethylene, benzene, toluene, and methane. Polyethylene - The toxicity and health effects of polyethylene are unknown, al though it is a suspected carcinogen. It Is produced through the polymerization of ethylene monomer, a gas, which Is moderately narcotic, but of low toxicity. Few, if any health problems would be expected as the result of exposure to re sidual ethylene monomer at concentrations present in wire and cable manufacturing plants. Exposure to heated polyethylene mixed with other plastic additives may result In irritation of eyes and respiratory tract due to two decomposition products; formaldehyde and acrolein. Polypropylene - The toxicity of polypropylene is not known. Propylene, which is used In the manufacture of polypropylene, Is a simple asphyxiant and anaesthetic. It is doubtful that residual amounts of propylene would cause a significant health threat at concentrations present in the wire and cable Industry. Nylon - The health hazards associated with nylon are unknown. FILLERS Calcium Carbonate Clay Carbon Black Silica For all, see discussion under rubber fillers. PLASTICIZERS Plasticizers are used to make plastics soft and flexible. Pthalates - Pthalates are the most commonly used plasticizers, and generally are of low acute toxicity. Prolonged exposure to hot mist or fees may produce irri tation to eyes, skin, and mucous membranes. Di-2-ethylhexylphthalate (DEtiPl - This compound has been found to be a liver toxi cant in primates. When it is metabolized it forms an extremely toxic agent. It has been shown to have cumulative toxic effects in mice. DEHP and dimsthoxyphthalate have produced chromosomal damage and caused antifertility effects in mice. Dimethyl, Dimethoxyethyl, Diethyl, Dibrtyl, Dimethobutyl, Dfoctyl, P.utylcarboxymethyl, and Di-2-ehthylhexyl phthalctes have caused teratogenic effects (birth defects) in animals. Tricresylohosphate (TCP) - TCP is used infrequently and can irr*>3te mucous mem branes. Careless or ^-.`cnged use c:n cause serious effects Inc'iwCtag certain types of paralysis. `HP is also a suspected carcinogen. 14 . STABILIZERS Stabilizers serve to prevent the decomposition of plastic compounds and are among the most hazardous chemicals used In plastic compounding. Barium Compounds - Barium compounds are often combined with either lead or cadmium compounds Into a stabilizer "blend". The toxicity of the barium alone Is not well known. Some soluble barium compounds are Irritating to eyes, nose, throat, and skin, and are toxic if Ingested. Blsphenol A (2,2 - bis (4 hydroxyphenyl propane)) - This stabilizer is of low toxicity, but can cause skin Irritation and Is a serious hazard to eyes. It Is suggested that workers who use it wear goggles. Cadmium Compounds - Inhalation of dust or fumes from these chemicals may cause dryness of the throat, cough, headache, shortness of breath, and vomiting. In addition, cadmium compounds are recognized carcinogens of the, connective tissue, lungs, and liver. Long term exposures may destroy lung tissue, resulting in emphysema. Cadmium based stabilizers are sometimes in liquid form, minimizing inhalation. Lead Compounds - Exposure to lead stabilizers is more hazardous than to metallic lead or lead oxide because the powders are readily inhaled and deposited on the hands. 011-wetted forms of the stabilizers provide a reduction of inhalation, hazards and pumpable slurries, if equipment is available to handle them, should eliminate most of the exposure hazard. Health effects of lead are covered on page 0 under Lead Oxides. Adequate ventilation, attention to personal hygiene, the use of regularly cleaned work clothing, and the prohabition of eating or smoking while working are indicated v/hen stabilizers are used. P1GI1ENTS OR COLORANTS See discussion on Rubber Polymers and Additives STRAINING AND MILLING After rubber compounding, the rubber is sent to either a strainer extruder, which takes out impurities, or to a mill to be further masticated, pressed, and cooled. In both machines the rubber compound is hot allowing potentially hazardous volatile components including any residual monomer, antioxidants, process oils or waxes, accelerators, and peroxides to be released into the workplace. There fore, local ventilation is recommended. Discussion of health hazards associated with specific chemical components of rubber insulating materials can be found in the section entitled Rubber Polymers and Additives. RUBBER DUSTING Dusting agents are commonly used to separate adjacent slabs of mixed rubber as well as cured or uncured rubber insulated wire and cable. Frequently used dusting agents include talc, mica, and zinc stearate. 15 Talc (soapstone) - Talc, or powdered hydrous magnesium silicate, is frequently used1 for both of the above mentioned purposes, and Its use often leads to air contamination In the area, the amount depending on the method of application. In the case of slab dusting, air contamination can be lessened by replacing talc with a "slab dip" or slurry consisting of a clay or zinc stearate suspension in water. Application of talct) rubber-covered wire Is ordinarily done by passing the wire through a "talc-box", which should be covered as well as possible to reduce the concentration of talc In the air. It Is well established that commercial talcs can contain substantial amounts of asbestos, which Is a definite hazard to lungs, producing pulmonary fibrosis and/or cancer. Certain grades of talc, however, contain little or no asbestos. To determine the extent of the health hazard, it is Important to determine the asbestos content of the talc. Talc itself may cause pulmonary fibrosis. Mica - Mica Is occassionally used for dusting rubber insulations, and while It Is a nonflbrous silicate, it can cause chronic fibrosis, a restrictive lung disease characterized by chronic coughing, weakness and weight loss. Zinc Stearate - This white powder Is sometimes used as a dusting agent for pur poses that require Its melting and absorption by the lubber. The inhalation of zinc stearate can cause pulmonary fibrosis. Adequate ventilation should be provided when these dusting agents are In use. RUBBER AHD PLASTIC EXTRUSION After the rubber and plastic compounds have been made into suitable in sulating materials, they must be applied to the wire. This is done primarily through the use of some type of extruder. Insulation is applied either as a "single shot" integral insulation and jacket, or as an insulation to be later combined with other "singles" into a multiconductor group and covered with an overall jacket. RUBBER EXTRUSION As the rubber Is being extruded onto the wire, it is cured in a continuous vulcanizing (CV) tube filled with high pressure steam. Little opportunity exists for inhalation of toxic chemicals in this process since it is all enclosed. An alternate method of extrusion for some cables involves feeding both the cable and the rubber compound into a lead press which then applies a lead sheath over the jacket of the cable. The lead press holds the rubber in a round shape and cures it. In some cases the sheath is left on, while in others it is removed with a stripping machine, melted and reused later. The stripping process releases small particles of lead into the workplace. These particles can be inhaled or ingested from contaminated hands. Because the lead is heated in order to melt it, exposure to lead fumes is another potential hazard. See discussion of lead hazards on page 8 under Lead Oxides. PLASTIC EXTRUSION Plastic compounds must be heated in the extruder before they can be formed around the wire. In nonautomated systems, the head of the extruder sits at working level about 4 feet from the floor and is uncovered so that it nay be attended by 16 the operator. As a result, operators may be exposed to plastic fumes. In automat ed systems, plastic compounds In the form of pellets are pumped directly Into the extruder reducing exposures to plastic chemicals. Even with automated systems, fumes may escape Into the workplace at the point where the newly insulated wire exits the extruder. Plastic fumes from compounds heated to normal extrusion temperatures of about 3D0-350F consist primarily of the plasticizer portion of the compound. Trace amounts of monomer may be present and could be given off during extrusion, but It would be expected that the mixing operation would have removed the major portion of such volatiles. The metallic salts present as stabilizers should be fully Incorporated into the compound and of no further concern at this point. The organic portions of these stabilizers may, however, be released. Hydrogen chloride (HGIl gas can be evolved from vinyl compounds during ex trusion, although it is expected that only small amounts of HCl would be given off at normal operating temperatures. Y There can also be exposure to purging compounds, usually ground plastic materials, or styrene, which are used to clean extruder screws of charred vinyl compounds. If heated too high, these compounds can release potentially toxic and irritating fumes. The process of bleeding the machine of a plastic compound of one color to replace it with one of another color also results in the release of potentially toxic substances. Therefore, for the above mentioned reasons, it is recoircnended that plastic extruders be equipped with local exhaust ventilation. SPARK TESTING Rubber insulated wire is passed through a high voltage electrode in order to locate faults in the insulation in a process called spark testing. Ozone gas can be generated by the electrode, the amount depending on the voltage used. Under 10 KV would not produce much ozone, but higher voltages produce greater amounts. It is not likely that much ozone would be produced during normal fault finding procedures since the^ectrode does not spark continously and ozone is self destructing. Any ozone that would be generated would disappear fairly quickly. However, when wire is tested in the laboratory to determine the adequacy of the insulation, significant amounts of ozone may be released if high voltage dielectric testing devices are left on for long periods of time. Operators of the devices should not be in the area if significant amounts of ozone are generated, and they should not return until the ozone has been exhausted. Ozone - The effects of ozone range from throat irritation at low concentrations to severe pulmonary edema (excess fluid in the lungs) at high concentrations. Very high concentrations of ozone may cause bronchitis characterized by persistent cough and excessive mucous production. In addition, animal experiments have shown that ozone at levels less than industrial health standards significantly affect the animals' antibacterial defenses. 17 BRAZING The purpose of brazing Is to join short lengths of wire through the use of some type of heated flux or solder. The procedure takes about 1% to 2 minutes for each braze and is done approximately 10 to 20 times per day. Depending on the type of flux or solder used, brazing may result in the release of potentially toxic fumes. One commonly used brazing material is silver solder which contains silver, zinc, and sometimes copper, brass, fluorides and cadmium. Silver Is Irritating to skin and mucous membranes and causes the skin to turn grey. However, it is not know to cause disability. When heated, fumes of zinc, brass, and copper may cause metal fume fever described on page 8. These metals, as well as fluoride and cadmium, may be Irritating to skin, eyes, and respiratory tract. Cadmium is a recognized carcinogen and long term exposure may result In destruction of lung tissue as well as liver and kidney damage. Fluorides have the potential for causing permanent lung damage. Local ventilation at the workbench Is recomnended to exhaust brazing fumes. Personal protective equipment should include safety goggles or shield, and gloves to protect workers from sparks or spatterings of brazing materials. 18 MEDICAL MONITORING Qf HQWSEB. HEALTH While many workers who are exposed to potentially hazardous substances will not develop a health-related problem. It Is very Important for exposed workers to seek medical attention. Medical monitoring of worker health, can often detect problems early enough to prevent them from becoming debilitating or life threatening. Since each worker is exposed to different agents depending on the type of job he/she does, there is no one set of medical tests which is suitable for everyone. Because different exposures can result In different health effects, each worker should see his or her physician for an individualized medical examination. There are, however, specific tests which can be performed to detect problems arising from particular exposures. 1) Anyone exposed to noise levels In excess of OSHA standards* for example wire drawers should be given pre-employment audiometry (hearing tests) to detect pre employment levels of hearing Impairment followed by annual audiometric tests to determine subsequent levels of impairment. 2) Pre-employment medical evaluations are advisable for workers who will be exposed to pulmonary irritants or agents causing pulmonary fibrosis such as asbestos, talc, mica, zinc stearate, silica (for example in clay or diatomaceous earth), and carbon black. The purpose of these evaluations is to determine the" existence of pre-employment pulmonary disease and to provide baseline data for future medical test comparisons. A chest X-ray after one year of employment is recommended to detect workers having early reactions to pulmonary irritants and fibrotic agents. The frequency of subsequent chest X-rays is controversial with recommendations ranging from 3 to 5 years. In addition to periodic chest X-rays, annual Pulmonary Function Tests (PFT's) should be performed on workers exposed to these substances. 3) Workers exposed to potential carcinogens should have thorough annual medical evaluations. These evaluations should include a complete blood count, a stool examination for the detection of occult blood, and a urinalysis. In particular, workers exposed to the following substances should have specific tests performed. a) Asbestos, - Chest X-Ray, Pulmonary Function Tests, Sputum Cytology. Special attention should be paid to the pulmonary, gastrointestinal, and cardiovascular systems. b) Benzidine, A20 Dyes, Naphthylamines - Annual Cytoscopy of the Urine. Special attention should be paid to people who are taking steroid prepara tions, cytologic drugs, or who smoke or are pregnant since they have an increased risk of contracting bladder cancer. 19 c) Cadmium - Pulmonary Function Tests, Chest X-Ray, Urinalysis with a quantitative analysis of protein In the urine. Special attention should be paid to the pulmonary and urinary systems. d) Chromates - Chest X-Ray, Pulmonary Function Tests, Urinalysis. Special attention should be paid to the skin as well as the pulmonary and urinary systems. e) Nickel Compounds - Chest X-Ray. Special attention should be paid to the examination of the nasal cavities, skin and pulmonary system. 4) Workers who are exposed to lead should receive annual physical examinations with special attention paid to the central nervous system as well as the gastro intestinal, urinary, and circulatory systems. Annual tests such as a complete blood count, urinalysis, and blood lead - Free Erythrocyte Protoporphyrin Testshould be performed. For more information about medical surveillance procedures, individual workers, unions, and management are encouraged to call one of the following occupational health medical testing facilities in the greater Providence area. 1) Rhode Island Hospital's Industrial and Environmental Medicine Clinic Providence, Rhode Island Andrew Rosner - Clinic Coordinator (401) 277-5723 2) Program of Occupational Medicine Brown University Michael Passero, M.D. - Director (401) 456-2060 3) Occupational Health Service, Sturdy Memorial Hospital Attleboro, Massachusetts Robert McCunney, M.D. - Medical Director (617) 222-5200 Ext. 3294 or 3295 4) The Rhode Island Poison Center, Rhode Island Hospital Providence, Rhode Island (401) 277-5727 20 WIRE AND CABLE REPORT AUTHORS. REVIEWERS AND INFORMATION SOURCES The principal authors are Robert Cones, Program Associate, Rhode Island Lung Association and Marilyn Vine, candidate for Master's Degree In Public Health, Yale University, Technical guidance regarding wire and cable chemistry and processes was provided by Gilbert Enser, While the responsibility for content Is that of the Lung Association, many knowledgeable individuals supplied information and/or reviewed report drafts for accuracy. We acknowledge the contributions made by the following: Labor Union Representatives Teresa Asselin United Steel Workers of America, Local 6224 Miller Electric Co. ` Woonsocket, RI David Barbosa United Rubber Workers, Local 339 Kaiser Aluniman and Chemical Corp. Portsmouth, RI John Donahue International Brotherhood of Electrical Workers, Local 1098 Collyer Insulated Wire Co. Lincoln, RI James Kearns International Brotherhood of Electrical Workers, Local 1196 - ITT Royal Electric Pawtucket, RI . Manuel Pimental International Brotherhood of Electrical Workers, Local 1780 R.I. Insulated Wire Co. Cranston, RI Thomas Steele International Brotherhood of Electrical Workers, Local 1542 Marragansett Wire Co. Pawtucket, RI Industrial Management Representatives John Hutton ITT Royal Electric Pawtucket, RI Milton Lyons Narragansett Wire Company Pawtucket, RI Apex Alkali Products Company Philadelphia, PA Associated Lead, Inc. Philadelphia, PA E. I. Dupont De Nemours and Co., Inc. Wilmington, Del. G. Whitfield Richards Co. Philadelphia, PA Hercules Inc. Wilmington, Del. R. T. Vanderbilt Co., Inc. Norwalk, Conn. Uni royal Chemical Naugatuck, Conn. Ware Chemical Stratford, Conn. 21 Other Reviewers and Information Sources Charles Andrews, P.E. Air Filter Systems East Providence, RI Sidney Braman, MO D1rector, Division of Pulmonary Diseases Rhode Island Hospital Providence, RI Steven Cohen, KD Yale University New Haven, Conn. William M. Corrao, MO Director of Pulmonary Function Laboratory . Division of Pulmonary Diseases Rhode Island Hospital Providence, RI Grace Donnelly, Ph.D. Biospec Inc. Providence, RI Germaine Dennaker RI Cancer Control Program Providence, RI Gilbert Enser Lincoln, RI James Hickey RI Dept, of Health Division of Occupational Health Providence, RI John T. Kaemmerlen, MD Veterans Administration Medical Center Providence, RI Cathy Kiley, MD Roger 111 11 lams General Hospital Office at Olneyville Providence, RI Herbert Kilgus RI Dept, of Health Division of Occupational Health Providence, RI Horace Martin, MD Rhode Island Hospital Division of Pathology Providence, RI James Nelson The Travelers Insurance Companies Providence, RI Michael Passero, MD Roger Williams General Hospital Division of Allergy and Occupational Medicine Providence, RI John Pella, MD St. Joseph's Hospital Pulmonary Division Providence, RI Margaret QuInnV Harvard School of Public Health Occupational Health Program Cambridge, MA Peter Rogtji Shawnee Chemical Company Plalnsboro, NJ Barkev Slroonian U.S. Dept, of Labor -- OSHA Boston, MA David Snapp RI Committee on Occupational Safety and Health Providence, RI Ellis Sokolov, P.E. Eco-Systems, Inc. Providence, RI Ues Straub National Institute for Occupational Safety and Health Boston, f*A Nicholas Tslongas, MD Kent County Memorial Hospital Warwick, RI Robert Ueisberg, Ph.D Midland Chemical Company Central Falls, RI V References Arnaud, A.."Polyvinyl Chloride Pneumoconiosis/ Thorax, 1978, 33, 19-25. Babbit, Robert 0. ed..The Vandertilt- Rubber Handbook- Norwalk: R.T. Vanderbilt Company, Inc., 1978. Brumbaugh, James E.. Welders Guide. Theodore Audel and Company: Indianapolis, 1973. Chest. 1980 78:2 Aug. Suppl. p. 374. . Clayton, G. and Clayton, F. eds..Patty's Industrial Hygiene and Toxicology 3rd Revised ed.. New York: 0. Wiley and SonsT Inc., 1981. Cordasco, E.H., M.D. et al.. "Pulmonary Manifestions of Vinyl and Polyvinyl Chloride (Interstitial Lung Disease)*; Chest, 78:6, December 1980, 828-834. "Cutting Oils and Coolants are Chief Culprits in Worker Skin Problems", Occupa tional Health and Safety., Sept. 1976, p. 16-21. y. Davies, Joan M., M.A. Oxon, Dip. P.S.A.. "Bladder Tumors in the Electric-cable Industry, '' lancet, 2 143-146- Delzell, Elizabeth S.D. and Richard R Monson, M.D.. "Mortality Among Rubber Workers: V. Processinq Workers," Journal of Occupational Medicine, vol. 24, no. 7, July 1982, 539-545. Eckardt, Robert E. M.D. Ph.D. and Richard Hlndin. "The Health Hazards of Plastics,1' Journal of Occupational Medicine, Vol. 15 No. 10 October 1973, 808-819. Fox, A.J. et. al.. "A Survey of Occupational Cancer in the Rubber and Cablemaking Industries: Results of five-year analysis, 1967-1971," British Journal of of Industrial Medicine, 1974, 31, 140-151. Fox, A.J. et al.. "A Survey of Occupational Cancer in the Rubber and Cablemaking Industries: Analysis of Oeaths occuring in 1972-1974/ British Journal of Industrial Medicine, 1976, 33, 249-264. Gloag, Daphne. "Asbestos, can it be used safely?'1, British Medical Journal. Vol. 282, H Feb. 1981. ---------------------------------------- Goldsmith, David F. H.S.P.H. et al.. "A Case Control Study of Prostate Cancer Within a Cohort of Rubber and Tire Workers/ Journal of Occupational Medicine, Vol 22 No 8 August 1980, 533-541. Hamilton, A. and H. Hardy, Industrial Toxicology. Acton: Publishing Sciences Group, 1974. . International Labor Office, Encyclopedia of Occupational Health and Safety. McGraw Hill Book Company: New York, 1972. Key, Marcus M. et.al. eds. Occupational Diseases - A Guide to Their Recognition. Washington, D.C.: U,S. Department of Health, Education and Welfare, 1977. Lilis, Ruth, M.D.. "Vinyl Chloride and Polyvinyl Chloride Exposure and Occupational Lung Disease," Chest, 78:6, December, 1980, 826-827.