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FILE NAME: BF Goodrich (BFG) DATE: 1947 DOC#: BFG053 DOCUMENT DESCRIPTION: Journal Article - Industrial Hygiene Quarterly 197 and Re marks marks !so an trkers IV). such presvalupro- i of * M !U . Ji I l i : i n u. ! OO; II! Sgi g a; i=s5Si . 'O Vol. 8, No. 4 INDUSTRIAL HYGIENE QUARTERLY Page 89 Health Protection in the Rubber Industry: Engineering Control _ W ILLIA M E. M cC O R M IC K Director of Industrial Hygiene and Toxicology B. F. Goodrich Company * Ak; m, Ohio The old adage of "An ounce of preven tion is worth a pound of cure" is a truism in industrial health, and the key the prevention of occupational disease is proper engineering control. The rubber in dustry has always been, by its very nature, a user and processor of chemicals, but it has been within the past few years that this has become especially true. As an industry we are now processors and, in some cases, manufacturers of huge quantities of many different chemicals. In order to properly safeguard the health of working personnel and concomitantly protect the best interests of the company, the necessary methods for using safely these various materials must be followed. With possibly very few exceptions, the industrial health hazards of greatest import to the rubber industry are those accruing from inhalation of toxic vapors, dusts, and fumes, and from dermatitis effects of var ious compounds. We have learned much during the past few years with respect to the proper handling of these materials. It is not so much now the question of deter mining the "know how" for safely using these items, as it is to see that accepted control measures are being used. From the standpoint of number of per sonnel, possibly exposure to solvent vapors constitutes the largest health problem. Both for this reason, and because time does not permit a more lengthly discourse, reference will.be made to the general industrial health control methods which are applicable to this group of materials. Fortunately the bulk of the solvents used are of the less toxic type. The control measures which can be generally used are substitution, enclosure, and ventilation. Substitution Quite repl freq aced uently with a a l tox ess i c to ma xic t eria one l ca wit n h be out loss of productivity. As an almost classical example now, the replacement of benzol by Presented before the Rubber Section of the National Safety Congress, October, 1947. less toxic solvents, particularly petroleum distillates in the rubber industry, might tobe mentioned. There are very few cases where the use of benzol as a solvent is a "must." Usually less toxic ones can be found. Numerous other exam;.'.es can be cited such as the use of trichlorethylene or perchlorethylene in place of more toxic carbon tetrachloride, tetrachlorethane, or ethylene dichloride; also, the use of ethyl alcohol in place of methyl. It should be remembered of course that the mere sub stitution of a less toxic compound for a more toxic one does not in every case solve the healih hazard. Additional control mea sures may be required. However, it is the first method which should be investigated. Enclosure or Isolation T^Tery frequently enclosure or even comv plete isolation of a hazardous operation can be effectively used as a control mea sure. Again, this may not in itself com pletely control the hazard; mechanical ven tilation or personal protective equipment may be required. Recently our company had occasion to handle on a pilot plant scale one of the more toxic compounds. After investigating the various possibilities of control, it was found that the construction of a small temporary building completely isolated from the remainder of the plant, was safest and cheapest method of us ing the material. The process was carried out in a closed system, but the isolation was necessary as a precaution in case of acci dental leaks. Many chemical manufacturing operations, fortunately, can be completely enclosed. In many cases the use of ele\ated pressures make this mandatory, and, thus, to a large degree controls any incident health hazards. In other cases, particularly at the institution of process, enclosure can be effectively and economically used. Ventilation The type of control one finds most fre quently is that of exhaust ventilation. Un fortunately it is often used incorrectly. Us Page 90 INDUSTRIAL HYGIENE QUARTERLY December, 1947 use involves more than just locating a wall fan in the general area and moving a large volume of air. Each process involves indi vidual study, and the type and amount of ventilation needed carefully determined. In many cases general ventilation--either na tural or mechanical--is satisfactory. In others, usually those involving exposure to the moi'e toxic materials, local exhaust ven tilation is a necessity. By this method the contaminant can be controlled at its source, a "must" in many instances. Even in those cases where general ventilation might be adaptable, the use of local exhaust ventila tion is often indicated due to its utilizing a much lower quantity of air. The added initial cost is often times cheaper in the long run due to lower heat losses and lower power consumption resulting from less air exhausted. Only the most careful study of each individual process can determine this. The type of installation made should be on the basis of both effectiveness and economy of control. Enclosure should be used to the maximum extent with any local exhaust ventilation. Any industrial health control measure should be instituted on the basis of certain basic industrial hygiene engineering prin ciples. 1. It must control the hazard. This re quires a thorough study of the process in volved, including the raw materials, the products and by-products, quantitative mea surements of atmospheric contaminants, and duration of exposure of working per sonnel. The control measures must be suf ficiently effective to maintain a safe work ing environment for personnel. Our pres ent knowledge of industrial hygiene en . ables us to say that any known health hazard can be controlled. It is a question of adapting the proper measures to the spe cific problem. No better proof of this than the manufacturing processes related to the atomic bomb is needed. 2. It must be economically practical. The ideal method of instituting health control measures is in the initial design of the plant or process. However, one must fre quently work with existing equipment. Re design may not be economically possible. The writer recently had occasion to review a graduate engineer's paper dealing with the control of a health hazard. The pro posed solution was theoretically excellent, except that the manufacturer would have* been put out of business financially in order to effect the control measures proposed. In dustrial health and safety still need to be sold. Every opportunity should be taken to indicate means of writing off the expen ditures involved in lower compensation costs, lower absenteeism, better employeeemployer relationships, less product con tamination. 3. It must not interfere with the em ployee's production. This is particularly true of those operations involving piece work wages. Little comment on this is necessary. The location of exhaust hoods and ventilating equipment must be such as not to interfere with production. Personal protective equipment particularly respira tory, should be used only as an adjunct to other control measures, or where other measures are wholly impractical. Notwith standing the fact that many commercial respirators are efficient devices, working personnel resist wearing them and often will do so only when actually compelled to. This, of course, is usually impractical, and frequently impossible. 4. It must meet local and state codes. This is particularly true with respect to maximum allowable concentrations of at mospheric contaminants, ventilation codes, and the release of atmospheric contamin ants out of doors. Little uniformity exists between different states and municipalities with respect to these various codes. Some are only advisory; others are legal statutes. A thorough investigation should be made of any existing codes before an installation is made. Following the installation, the necessary measurements should be made to determine the effectiveness of the control.