Document rn5g7yddVbrm0Rr9Kvq7xn3E

FILE NAME: &'ZZ&' DATE: DOC#: &' DOCUMENT DESCRIPTION::Z/,Y , 1947 and Remarks marks so an )rkers IV). such presvalupro- VoL. 8, No. 4 INDUSTRIAL HYGIENE QUARTERLY Page 89 Health Protection in the Rubber Industry: Engineering Control WILLIAM E. McCORMICK Director of Industrial Hygiene and Toxicology B. F. Goodrich Company Ak; ,n, Ohio rTHE OLD ADAGE of "An ounce of preven- tion is worth a pound of cure" is a truism in industrial health, and the key to the prevention of occupational disease is proper engineering control. The rubber industry 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 various 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 determining 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 personnel, 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 frequently a toxic material can be replaced with a less toxic one without 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, 1347. less toxic solvents, particularly petroleum distillates in the rubber industry, might be mentioned. There are very few cases where the use of benzol as a solvent is a "must." Usually less toxic ones can be found. Numercus other examl.les can be cited such as the use of trichiorethylene 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 substitution of a less toxic compound for a more toxic one does not in every case solve the health hazard. Additional control measures may be required. However, it is the first method which should be investigated. Enclosure or Isolation VERY FREQUENTLY enclosure or even complete isolation of a hazardous operation can be effectively used as a control measure. Again, this may not in itself completely control the hazard; mechanical ventilation or personal protective equipment may be required. Recently our company had occasion to handle nil 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 the safest and cheapest method of using the material. The process was carried out in a closed system, but the isolation was necessary as a precaution in case of accidental leaks. Many chemical manufacturing operations, fortunately, can be completely enclosed. In many cases the use of eleN ated preaures 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 frequently is that of exhaust ventilation. Unfortunately it is often used incorrectly. Its Page 90 INDUSTRIAL HYGIENE QUARTERLY December, 1947 use involves more than just locating a wall measures is in the initial design of the fan in the general area and moving a large plant or process. However, one must fre- volume of air. Each process involves individual study, and the type and amount of ventilation needed carefully determined. In many cases general ventilation--either na- quently work with existing equipment. Redesign may not be economically possible. The writer recently had occasion to review a graduate engineer's paper dealing with tural or mechanical--is satisfactory. In others, usually those involving exposure to the more toxic materials, local exhaust ven- the control of a health hazard. The proposed solution was theoretically excellent, except that the manufacturer would have' tilation is a necessity. By this method the been put out of business financially in order contaminant can be controlled at its source, to effect the control measures proposed. In- a "must" in many instances. Even in those dustrial health and safety still need to be cases where general ventilation might be sold. Every opportunity should be taken adaptable, the use of local exhaust ventila- to indicate means of writing off the expen- tion is often indicated due to its utilizing ditures involved in lower compensation a much lower quantity of air. The added costs, lower absenteeism, better employee- initial cost is often times cheaper in the employer relationships, less product con- long run due to lower heat losses and lower tamination. power consumption resulting from less air 3. It must not interfere with the em- exhausted. ployee's production. This is particularly Only the most careful study of each true of those operations involving piece- individual process can determine this. The work wages. Little comment on this is type of installation made should be on the necessary. The location of exhaust hoods basis of both effectiveness and economy of and ventilating equipment must be such as control. Enclosure should be used to the not to interfere with production. Personal maximum extent with any local exhaust protective equipment particularly respira- ventilation. tory, should be used only as an adjunct to r Any industrial health control measure other control measures, or where other should be instituted on the basis of certain measures are wholly impractical. Notwith- basic industrial hygiene engineering prin- standing the fact that many commercial ciples. respirators are efficient devices, working 1. It must control the hazard. This re- personnel resist wearing them and often quires a thorough study of the process in- will do so only when actually compelled to. volved, including the raw materials, the This, of course, is usually impractical, and products and by-products, quantitative mea- frequently impossible. surements of atmospheric contaminants, 4. It must meet local and state codes. and duration of exposure of working per- This is particularly true with respect to sonnel. The control measures must be suf- maximum allowable concentrations of at- ficiently effective to maintain a safe work- mospheric contaminants, ventilation codes, T ing environment for personnel. Our pres- and the release of atmospheric contamin- ent knowledge of industrial hygiene en- ants out of doors. Little uniformity exists ables us to say that any known health between different states and municipalities hazard can be controlled. It is a question with respect to these various codes. Some II of adapting the proper measures to the spe- are only advisory; others are legal statutes. cific problem. No better proof of this than A thorough investigation should be made the manufacturing processes related to the of any existing codes before an installation atomic bomb is needed. is made. Following the installation, the 2. It must be economically practical. The necessary measurements should be made to n ideal method of instituting health control determine the effectiveness of the control. ti h d it ti tr e( c: cc.