Health hazard evaluation report: HETA-2000-0020-2793, U.S. Forest Service, Coconino National Forest, Flagstaff, Arizona.
In October 1999, the National Institute for Occupational Safety and Health (NIOSH) received a health hazard evaluation request from a management representative of the United States Forest Service (USFS). The USFS sought to evaluate the potential hazards associated with using petroleum-based tree-marking paint (TMP) to paint various wooden structures within the National Forest system. On December 14, 1999, NIOSH industrial hygienists went to the Coconino National Forest near Flagstaff, Arizona, to evaluate worker exposures to various volatile organic compounds (VOCs) and metals during the application of petroleum-based TMPs to the exterior of a wooden building in the park. Paint mixing, painting, and clean-up activities were monitored. Personal breathing zone and area samples were collected for metals, methyl ethyl ketone (MEK), methyl isobutyl ketone, toluene, and total hydrocarbons (using stoddard solvent as the standard). No over exposures were documented during this survey; contaminant levels were generally more than one order of magnitude below their most conservative exposure criterion. Bulk paint samples of the tree-marking paint and acrylic stain were collected for metals and hydrocarbon analysis. Major hydrocarbon constituents of the paints were C9-C12 aliphatics and C9-C10 alkyl benzenes, and included toluene, xylene, MEK, undecane, and decane. Based on the USFS Draft Specification 2400-400 (May 2000), none of the paints used during this survey would have passed the USFS criteria for metals content. There was not a health hazard either from the VOCs or metals present in the TMP. Sufficient precautions are being taken by the USFS in preparing the painters to use the TMP. These precautions include conducting a job hazard analysis discussion before painting, using personal protective equipment during paint mixing, painting, and cleanup; mixing the paint and cleaning up outdoors; and minimizing the aerosolization of the paint during its application. Analysis of bulk paint samples demonstrated that paints used during this survey would not have met the current USFS Draft TMP Specification for metals content.