11-265/266). by titration or any method. The Agency proposed a PEL of 0.2 ppm (1.5 mg/m 3) as a ceiling for this substance to protect workers against the significant risk of eye and skin irritation, as well as kidney and liver damage; this limit is consistent with that of the ACGIH. CDC is not responsible for Section 508 compliance (accessibility) on other federal or private website. A study by Moskowitz and Grabois (1950, as cited in ACGIH 1986/Ex. Ft. @ 10 Mil. Methyl Ethyl Ketone Peroxide (MEKP) is the chemical hardener used with polyester resin. In addition, this commenter stated that information is lacking as to what concentrations of MEKP currently exist in the workplace, how to measure MEKP in the occupational environment, and the feasibility of engineering controls to regulate exposures to MEKP (Ex. 11-265/266). HE 79-132-673; HE 76-000-066; and HE 78-003-555). Fluid Ounce. 1-783) demonstrated that MEKP is significantly more toxic than benzoyl peroxide (TLV-TWA of 5 mg/m3) and resembles hydrogen peroxide (TLV-TWA of 1.4 mg/m3) in terms of its potential to cause irritation on an acute basis. In the low-production facility, all MEKP sampling results for gel-coat and lamination workers were below 1.5-mg/m3 for MEKP (Ex. CC Oz. of Catalysts to be Used with Polyester Resins MEKP - Number of oz. ), (Last column is the number of square feet a given volume will cover at a thickness of 10 Mil (.010") wet. Inhalation of MEKP vapors produced petechial and gross hemorrhages of the lungs in rats after four-hour exposures; liver and kidney damage was also observed (Floyd and Stokinger 1958/Ex. At the third site, a total of 20 short-term samples were taken over a three-day period to determine airborne MEKP exposures during the construction of fibrous glass reinforced products utilizing the styrenemodified polyester resin sprayup process and a MEKP catalyst; eight of these short-term samples exceeded the 1.5-mg/m3 (0.2-ppm) level (NIOSH Health Hazard Evaluation Determination Report No. New email subscribers will receive a 10% off Promo Code! As discussed in Section VII of the preamble, OSHA’s entire costing methodology is based on a process approach that assumes multiple chemical exposures and the use of a system of engineering controls designed to control the exposures of all employees involved in the process. Thorough mixing of catalyst into resins and gelcoat is very important. CC Oz. One plant was a high-volume facility that produced approximately 24 boats per day, while the other plant produced only two to three boats per day. 1-3, p. 396), this study demonstrated that MEKP was “20- to 50-fold more acutely toxic than di-t-butyl peroxide by all routes tested.” The consequences of exposure to this substance ranged from skin and eye irritation to gross hemorrhage of the lung and liver and kidney damage; OSHA notes that these effects were observed even after short-term exposures. Specific gravity  MEK peroxide seq. Also the correct additions should be observed to maintain good results. 8-86 and 155). Ft. @ 10 Mils), Catalyst Concentration by CC (Volume of Catalysts to be Used with Polyester Mr. Schumacher (Ex. OSHA believes that the higher reading at the second facility is accounted for by the high rate of production at that site; controlling exposures at a high-volume facility requires the implementation of additional controls to compensate for the increase in production. For example, the Floyd and Stokinger study reports that MEKP is “20- to 50-fold more acutely toxic than di-t-butyl peroxide by all routes tested”; however, there is no PEL or TLV for d-t-butyl peroxide for OSHA to use as a basis for the PEL.