Hexavalent chromium is the standard that catches employers who do not believe they work with chemicals. Nobody orders a drum of it. It is generated — by welding stainless steel, by torch cutting coated structural members, by grinding chromate primer off an aircraft part, by thermal spray. The employer buys steel and rod, and the process makes the contaminant.
The two numbers
8 CCR section 5206 sets a permissible exposure limit of 5 micrograms of chromium (VI) per cubic meter of air as an 8-hour time-weighted average, and an action level of 2.5 micrograms per cubic meter, also as an 8-hour TWA.
Both numbers are small enough that intuition is useless. There is no amount of experience that lets a supervisor look at a welding booth and estimate whether it is over 5 micrograms. The only way to know is to sample, and the standard says so.
Initial monitoring
The employer determines the 8-hour TWA exposure for each employee exposed to chromium (VI), using personal breathing zone samples in sufficient number to accurately characterize full shift exposure on each shift, for each job classification, in each work area.
Read the four qualifiers. Each shift. Each job classification. Each work area. One sample on the day shift welder does not characterize the swing shift, the grinder, or the bay on the other side of the building. Where several employees perform the same job on the same shift in the same area, sampling a representative fraction is permitted, and the representative sample is taken on the employee reasonably expected to have the highest exposure.
How often after that
- At or above the action level but at or below the PEL: monitor at least every six months
- Above the PEL: monitor at least every three months
- Below the action level: periodic monitoring may be discontinued, on the terms the standard sets
A change in the production process, raw material, equipment, personnel, work practices or control methods that may result in new or additional exposure requires the determination to be made again. Switching rod, changing base metal, or moving a booth all qualify.
Regulated areas
Where an employee’s exposure is, or can reasonably be expected to be, in excess of the PEL, the employer establishes a regulated area — demarcated from the rest of the workplace and limited to authorized persons, employee representatives observing monitoring, and persons authorized under the Act or its regulations. In a shop that has never drawn a line on the floor, this is the requirement that reorganizes the building.
Medical surveillance
Surveillance is owed to employees occupationally exposed at or above the action level for 30 or more days a year, to any employee showing signs or symptoms of the adverse health effects associated with chromium (VI) exposure, and to any employee exposed in an emergency.
Thirty days a year is a low bar in a fabrication shop. It is two and a half days a month. Employers who assume surveillance is for full-time exposure miss it routinely.
What the records have to show
Air monitoring results belong to the employee as exposure records under 8 CCR section 3204 and have to be preserved and maintained for at least thirty years. Employees and their designated representatives get access, and under section 3204(e)(1)(A) access is provided in a reasonable time, place and manner, and in no event later than fifteen days after the request. An employer who sampled once in 2019 and cannot now find the report has two problems, and the missing report is the smaller one.
Michael Karl McNeil — environmental health and safety, industrial hygiene, Cal/OSHA citation defense.
