National Institute for Occupational Safety & Health Report on Diesel Exhaust Fume Exposure
Several studies over the past five years indicate that workers exposed to diesel exhaust over a number of years are more likely to contract lung cancer in addition to other maladies.
Earlier studies had only identified irritation of eyes and temporary breathing problems as being related to inhalation of diesel smoke, due to the difficulty of isolating the many other factors which contribute to other, more serious ailments. These include asbestos exposure and cigarette smoking. More recent studies controlled these factors and found a statistically significant number of cancers and tumors among such workers. Also, recent experiments in which rats and mice were exposed “confirm an association between the induction of cancer and exposure to whole diesel exhaust.” The consistency in the findings of the worker histories and the animal experiments “suggests that a potential occupational carcinogenic hazard exists in human exposure to diesel exhaust.”
Not only is the particulate matter associated with cancer: the gases in diesel exhaust are suspect as well. According to NIOSH Current Intelligence Bulletin 50, “The emissions from diesel engines consist of both gaseous and particulate fractions. The gaseous constituents include carbon dioxide, carbon monoxide, nitric oxide, nitrogen oxide, oxides of sulfer, and hydrocarbons (e.g., ethylene, formaldehyde, methane, benzene, phenol, 1, 3-butadiene, acrolein, and polynuclear aromatic hydrocarbons). Particulates (soot) in diesel exhaust are composed of solid carbon cores that are produced during the combustion process and that tend to form chain or cluster aggregates. More than 95% of these particulates are less than one micrometer in size. Estimates indicate that as many as 18,000 different substances from the combustion process can be absorbed onto diesel exhaust particulates. The absorbed material constitutes 15% to 65% of the total particulate mass and includes such compounds as polynuclear hydrocarbons (PAHs) several of which are carcinogens.”
On the basis of these studies, NIOSH recommends that whole diesel exhaust be regarded as “a potential occupational carcinogen.” Although current experimental data is not sufficient to quantify the risk one runs of contracting cancer from diesel exhaust, NIOSH assumes that reductions in exposure to diesel exhaust in the workplace would reduce the excess risk.” NIOSH recommends that users of diesel-powered equipment inform their workers and that professional and trade associations and unions inform their members of the new findings of potential carcinogenic hazards of exposure to diesel engine emissions, and that all available preventitive efforts be vigorously implemented to minimize exposure of workers to diesel exhaust.”
Those interested in receiving Current Intelligence Bulletin 50, entitled “Carcinogenic Effects of Exposure to Diesel Exhaust” may contact NIOSH at 513-533-8287 from 8:30 am – 4:40 pm (EST).
OSHA Publishes Rules Governing Exposure to Hex Chrome
The Occupational Safety and Health Administration has published a final standard for exposure to hexavalent chromium (hex chrome). The standard covers occupational exposure to hex chrome.
“OSHA has worked hard to produce a final standard that substantially reduces the significant health risks for employees exposed to hexavalent chromium. Our new standard protects workers to the extent feasible, while providing employers, especially small employers, adequate time to transition to the new requirements,” said Jonathan L. Snare, acting assistant secretary for occupational safety and health.
Hexavalent Chromium: What It Is Hexavalent Chromium Cr(VI) is a metal particle that can occur naturally in rocks but is most commonly produced by industrial process. It has the ability to gain electrons from other elements (a strong oxidizer), which means it can react easily with them. Because of its ability to react with other elements, it can produce hard coatings, which is why it is used in paints for cars, boats and airplanes. This property is also what makes hexavalent chromium a health hazard. Hexavalent chromium is often referred to as Hex Chrom, Hex Chrome, Chromium 6, HexaChrom, Cr(VI), HexChrome, etc.
OSHA Standard Overview On February 28, 2006, the Occupational Safety and Health Administration (OSHA) published the final Hexavalent Chromium Cr(VI) Standard. The new permissible exposure limit (PEL) for Cr(VI) is 5µg/m3 (micrograms per cubic meter). There are three standards for different industries: General Industry, Construction, and Shipyards. The respiratory protection requirements for the three standards are similar. A respiratory protection program, including respirator selection, is required to follow OSHA 1910.134.
Main Industries and Applications Affected The primary industries affected, according to OSHA, are Stainless Steel Fabrication, Heavy Duty Coatings and Paints (Automobile, Train Car, Airplane, Boats, Ships), electroplating and producers of chrome-based pigments. Welding (especially on stainless steel), spraying heavy-duty coatings and paints, and chrome plating are the primary applications affected.
Monoxivent products providing capture of hex chrome include: Portable (PHS/HEPA) Welding Arms, 15000 Series Arms, MNX Collectors with HEPA After Filter
OSHA Fact Sheet (PDF) for Hex Chrome: click here
Additional detailed information is available at www.osha.gov