What are the safe harbor levels for silica? Is it mandatory to include the warning labels on products?
Silica appears to be specific to respiratory issues during manufacturing (from the occurrences/uses section). If, after the manufacturing of the products, there is a chance of a consumer inhaling the silica above the 3 μg/m³ per day exposure threshold, then a label is likely needed. If there is no chance of exposure or it is below the 3 μg/m³ per day limit, then a label is probably not required. There is likely still a need to provide the information to workers under OSHA, but the Prop 65 warning requirement would not be applicable to the manufacturing process where end-users are not making purchases of finished goods.
Here is an excerpt from the Proposition 65 website about Silica:
- Silica (crystalline, respirable)
- Chronic REL
|Chronic Inhalation REL (μg/m3):||3|
|Chronic Target Organs:||Respiratory system|
- Manufacture of glass, abrasives, ceramics, enamels, heat insulators, fire- and acid-prove packing materials; clarifying and filtration agent, molds for castings, decolorizing and purifying oil/petroleum, industrial filler
**Article contents valid as of 2017-06-13