Occupational exposure limits for novel work schedules

Work schedules other than 7 to 8 hr/day and 40 hr/week are being introduced in many industrial operations. Novel work schedules, such as four 10-hour workdays per week or three 12-hour workdays per week for three weeks followed by four 12-hour workdays for three weeks and several other plans are presently being used. The Threshold Limit Values (TLV) do not apply to such novel schedules. Modified occupational limits, which are calculable from the methods suggested in this report, estimate the needed reduction in the TLV to provide protection for exposed workers. A simple system is suggested, but should be cautiously applied with good medical surveillance. Industrial hygiene experience with novel work schedules will ultimately provide the real requirements for acceptable exposures under such work conditions.