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An exposure assessment survey of an isothiazolinone-based biocide among power plant workers.

Cook C
American Industrial Hygiene Conference and Exposition, May 19-23, 1997, Dallas, Texas. Fairfax, VA: American Industrial Hygiene Association, 1997 May; :77-78
In September 1995, the National Institute for Occupational Safety and Health (NIOSH) conducted an industrial hygiene survey at a manufacturing plant to assess power plant workers' exposures to biocide containing 1.5% isothiazolinones. After isothiazolinone-based biocide was first introduced at the plant in 1987, workers reported dermatitis, skin rash, eye and upper respiratory irritation while performing maintenance duties on water cooling towers. Employees became particularly concerned about the known mutagenicity properties of the biocide. Isothiazlinones are heterocyclic organic compounds present in several chlorinated and unchlorinated forms. Isothiazolinones are nonoxidizing antimicrobial agents that are effective against gram-positive and gram-negative bacteria, as well as fungi, yeast, algae, and Legionella pneumophila. Isothiazolinones are used industrially as antibiofoulants and slimicides in metalworking fluids, paper mills, swimming pools, leather and fabric, and water cooling towers. Sixteen personal breathing zone (PBZ) samples (13 full-shift, three 15-minute short-term) and 21 area air samples for isothiazolinones were collected. Analyses of PBZ samples revealed none-detectable levels. A 15-minute area air sample collected above a biocide storage tank measured isothiazolinone concentration of 0.92 milligrams per cubic meter (mg/m3), exceeding a chemical manufacturer's recommended 15-minute short-term exposure limit (STEL) of 0.30 mg/m3. A second area air sample revealed a trace concentration at an employee break area. Currently, there are no occupational exposure criteria established by NIOSH or the Occupational Safety and Health Administration (OSHA) for isothiazlinones. NIOSH concluded a potential for short-term exposure above a manufacturer's exposure criteria of 0.30 mg/m3. Dermal exposure to the biocide may also pose a health hazard if proper protective clothing is not worn during its use. Recommendations were made to help prevent worker exposure to the biocide during water cooling tower maintenance.
Industrial-hygiene; Workers; Work-environment; Exposure-levels; Biocides; Dermatitis; Skin; Skin-exposure; Skin-irritants; Skin-sensitivity; Eye-irritants; Eyes; Respiratory-irritants; Respiratory-system-disorders; Mutagenicity; Heterocyclic-compounds; Chlorides; Chlorine-compounds; Bacteria; Fungi; Yeasts; Metalworking-fluids; Paper-mills; Leather-industry; Fabrics; Breathing-zone; Air-samples; Hazards; Health-hazards
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American Industrial Hygiene Conference and Exposition, May 19-23, 1997, Dallas, Texas
Page last reviewed: May 11, 2023
Content source: National Institute for Occupational Safety and Health Education and Information Division