Document nJX2QLzgK55jVMNZMdaa7xBa

Vista Chemical Company 15990 N. barker's Lancing Rd. Post Office Bex 19029 HoustQDjpus 77224^7 __ XF:U '^-r\v%n 0 !\~y j November 22, 1985 Mr. Ron Bland Huges Drilling Fluids 10777 Northwest Freeway Houston, XX 77092 Dear Ron: This letter is to confirm our discussion regarding the labeling of Vista*s ODC Drilling Oil and our hazard determination. You are aware of the jDSHA^CarcInogenic warning labeling requiremi which applies to materials which have^ heen 'Vvaluated";under vaj testing conditions and .shown;^lgnlficant-positive.results or for those which have not been tested contain greates^Q^lj! or volume of a known' carcinogen. ^l^owi^cagc^Qeem^^are^1 def: chose chemicals listed by the" National Toxicoloi International Agency for Research on Cancer Croups I and lI, and those which OSHA regulates as a Carcinogen'. In some cases evaluation of IARC listed categories is required to determine specific chemicals. Vista ODC contains no OSHA defined carcinogens, for purposes of the Hazard Communication Standard, at levels greater than 0.12. As for the broad categories of "mineral oils", petroleum oils, or ocher generic classifications of oils which have been, indicated to have a carcinogenic potential by various studies we believe the following to be true in respect to Vista ODC. IARC Monograph, Volume 33 (portions attached) classifies petroleum derived oils based on the increasing severity of processing or refinement. This monograph deals with oils that are predominately lubricant base oils with initial boiling points exceeding 750F and carbon number distributions of 15 or greater. Vista*s ODC has an I3P of 370 F and has a carbon number distribution. Of chose oils discussed in the monograph Vista ODC is closest to the white oil (class 5) classification, for which the only evidence for carcinogenicity is of questionable significance to human exposures. Sincerely, Thomas G. Grumbles, CXH Environmental Quality Manager ajo/8 Attachment cc Dan Plummer, John Nelson, Pat Quinlan ^ OQOOl7^1-2