Document xjBeD9XwwRZRBK29p1Kq1bK7Q

APPENDIX D 1910.93q Vinyl Chloride * * * (f) Monitoring < (1) Every regulated area shall be continually se quentially monitored for levels of vinyl chloride. (2)(i) Probes shall be so located in every regulated area as to provide a statistically valid sample of the workplace atmosphere. Analysis shall be conducted on samples obtained from each probe in a sequential manner so that the atmosphere at each site is analyzed. (ii) The validity of the location of the probes and frequency of analysis of the samples obtained from each probe shall be assured by comparison of the results obtained by the area monitoring system with those obtained by personnel monitoring conducted at the same time for periods of at least four hours, and preferably longer. After the validity of a new continual sequential monitoring system has been established, it shall be similarly re-validated at intervals not exceeding three months. (iii) The analytical instruments shall be checked and re-calibrated to assure proper functioning at intervals not exceeding one month. The analytical instruments must be capable of measuring the vinyl chloride concentration in air at concentrations in the range of 5 - 100 ppm with an accuracy of + 10% of the measured value. For calibration and "referee" purposes, a gas chromatograph equipped with a flame ioni zation detector shall be used, and certified calibration gas mixtures shall be used as standards. (iv) The monitoring equipment shall produce an audible and visible alarm in any plant area when the concen tration of vinyl chloride in that area exceeds- the limit set forth in paragraph (b). (v) The monitoring equipment shall also produce an audible and visible alarm, readily distinguishable from that required by (f)(2)(iv) in any plant area when the concentration of vinyl chloride in that area exceeds 100 ppm. k ic 'k GENC 009538