Document 5bGzOjzm9bNw7vjBk6DGqn1je

POTENTIAL EXPOSURES IN INDUSTRY 2243 Armature Workers Lead "tinning" baths and lead pots, when small and equipped with tempera ture controls, may not present serious lead exposures. However, the larger opera tions, especially when no temperature control is in use, can offer serious exposures. Wherever there is any question of exposure, the operation should either be pro vided with mechanically induced air flow to remove or dilute the lead fumes before they can be inhaled, or else air, blood, or urine samples should be collected and analyzed for lead to establish whether ventilation is necessary. Waterproof varnishes, especially those made from cashew nutshell liquidformaldehyde resins, may cause dermatitis. This may result from contact with the wet varnish, from the varnish dust dispersed in grinding armatures, or from skin contact with dirty solvent baths for dipping and cleaning old armatures. The solvent bath should not be permitted to become badly contaminated and skin contact must be avoided. In the case of wet or dry varnish, good personal cleanli ness is an effective preventive measure, and varnish dust should be controlled by process ventilation. Protective creams and clothing may be useful in some instances. Art-Metal Casting Art-metal casts for displays, trophies, medals, and the like are usually cast from white metal or britannia metal, which are alloys of t|n, antimony, and copper, often having some zinc and bismuth, occasionally lead, and possibly arsenic. The alloys are melted in pots, temperatures rarely exceeding 300 or 400C. Burring, filing, belt "sanding," and buffing may be done and, unless con trolled, significant exposures to mechanically generated metal dusts may result. At the temperatures ordinarily employed there is little likelihood of an exposure to metal fumes, however. Where uncertainties exist, exposures should be evaluated and, when found excessive, controlled. Other possible exposures in the industry involve plating baths and cyanide dips. Soldering operations are usually at low temperatures to avoid fusing the low-melting-point alloys, and therefore are not conducive to the formation of metal fumes. Asbestos Workers Dustiness around asbestos workers is sometimes above the proposed standard of 5 million particles per cubic foot. Perhaps mining offers the greatest exposure to dust, arid in fabrication plants the operations, listed in the probable, decreasing order of dustiness, are: screening, picking, stacking, and willowing in the prepara tion room; carding, dry weaving, spinning, twisting, winding, and warping. The sawing, filing, drilling, arid grinding of brake linings is ordinarily well controlled. Grinding, mixing, and bagging asbestos cement and insulating material, and the sawing or beveling of asbestos board, are dusty operations unless properly engi neered. The asbestos content of these dusts frequently is not high but diatomaceous