Document q47dRNrREpGjDGgRkwJy40Vq

INDUSTRIAL CHEMICALS DIVISION SHELL CHEMICAL COMPANY A DIVISION Of SHELL OIL COMPANY ONE SHELL PLAZA HOUSTON, TEXAS 77002 oi-vtyfcvc- Sr## Gentlemen: The necessity for limiting and controlling human exposure to high concentrations of vinyl chloride has been long recognized by industry. A 500 ppm ceiling value is specified by the Department of Labor, under the Occupational Safety and Health Act, as the permitted employee exposure level to vinyl chloride. The most recent Manufacturing Chemists Association safety data sheet for vinyl chloride reports this value. A copy of this data sheet is enclosed for your information. In June of 1972, the American Conference of Governmental Industrial Hygienists (ACGIH) adopted an eight hour time weighted average Threshold Limit Value (TLV) of 200 ppm (vol/vol) for vinyl chloride. Documentation covering the considerations leading to the adoption of this value may be obtained by request to the Chairman, TLV Committee, American Conference of Governmental Industrial Hygienists, P. 0. Box 1937, Cincinnati, Ohio 45201. While the ACGIH adopted a 200 ppm level for vinyl chloride, the TLV Documentation cites studies which recommend levels from 50 ppm to 500 ppm. As you may be aware, the Manufacturing Chemists Association has contracted with independent consultants, on behalf of a group of vinyl chloride producers and consumers to conduct animal exposure stud;as and a comprehensive epidemiology study of vinyl chloride workers. It is hoped that results from these studies will aid in clarifying what exposure limitation would be most appropriate. However, until these results are available and in view of the range in recommendations, we considered it prudent in our operations to establish a vinyl chloride TLV of 50 ppm; further, measurements indicate that this is a feasible level for us. We urge you to give consideration to the vinyl chloride exposure levels which may be appropriate for your operations. 000021295 AS I We would be pleased to make available our techniques for measuring low concentrations of vinyl chloride if you would consider them helpful. Very truly yours, SHELL CHEMICAL COMPANY R. 0. Reynolds Manager, Vinyl Chloride Business Center Attachment: MCA Safety Data Sheet SD-56 (1972 Version) f/ool(ei~ <*0. po c^'c. firte* G p- Gc'ecQ-'U cJ<<. P Pc, p'f fe u.-e. ( -fi h e. c<^j ( hbiUcs c^.[) AS! 000021296