BPA (bisphenol A), detected in the urine of over 92% of the general population. is used primarily in making polycarbonate plastic and some epoxy resins. The general population is exposed to BPA mainly through diet. Trace levels of BPA may be present in food or beverages in contact with polycarbonate containers or epoxy resins coatings on the inside of cans.
In addition to BPA’s use in making polycarbonate and epoxy resins, BPA is used in making phenolic resins and certain specialty waxes used in the “lost wax” process for casting metal parts. Resins made with BPA contain only trace levels of BPA; that is, nearly all of the BPA has been chemically-reacted in making the resin. Therefore, under normal conditions of use, touching products such as polycarbonate safety glasses does not lead to BPA exposure. By contrast, BPA remains intact in waxes and thermal paper made with BPA; that is the percentage of BPA used in making the wax or paper remains in the final product.
Neither NIOSH, the Occupational Safety and Health Administration (OSHA,) nor the American Conference of Governmental Industrial Hygienists (ACGIH) have occupational exposure limits for BPA.
As good practice and as part of continuous improvement efforts, NIOSH encourages companies to review work processes and practices for ways to minimize worker exposure to BPA by following the hierarchy of controls.
Exposure reduction steps could include:
- Eliminating BPA or substituting other chemicals for BPA. In applications where BPA is an essential building block (component) of a material, such as in polycarbonate plastic, substitution may not be an option;
- Containing BPA dust and vapor emissions with either full enclosures or local exhaust ventilation;
- Minimizing the time workers spend in BPA production areas;
- Cleaning surfaces in production areas, offices, and lunch rooms regularly to remove BPA residues;
- As a last resort, using personal protective equipment (PPE) and assuring that PPE is properly fitted, worn, maintained, and cleaned. PPE may include respirators, chemically-resistant gloves and suits, and eye and face protection; and
- Implementing a sampling program for BPA to evaluate the efficacy of controls and surface decontamination efforts.