In January 2021, the U.S. EPA published final rules under the Toxic Substances Control Act (TCSA), restricting five PBT substances (see table below).
One of the substances, phenol, Isopropylated Phosphate (3:1) (PIP 3:1), is used in EEE for various applications and its restriction in articles is being raised as a concern for the EEE industry due to a very short restriction timeline (March 8, 2021). Several exemptions were requested and approved for PIP 3:1 when used in lubricants and fluids (e.g., for aircraft and automobiles), but there was little attention put on the substances use in imported articles.
Several industry associations have contacted the EPA for clarification, and if the substances are restricted in articles, to request an extension of the deadline. The most immediate issue being that the timeline isn’t even sufficient to check with the supply chain as to whether or not PIP 3:1 is present in parts, let alone to redesign if present.
Table 1: PBT substances restricted by U.S. EPA
| Substance name | CAS number | Typical EEE Applications | Restriction Date | Link to Final Rule |
|---|---|---|---|---|
| 2,4,6-tris(tert-butyl)phenol (2,4,6-TTBP) | 732-26-3 | Antioxidant in rubber and plastics, heat stabilizer for polyethylene, polypropylene, and high impact polystyrene | January 6, 2026 | https://www.federalregister.gov/documents/2021/01/06/2020-28690/246-tristert-butylphenol-246-ttbp-regulation-of-persistent-bioaccumulative-and-toxic-chemicals-under |
| Decabromodiphenyl Ether (DecaBDE) | 1163-19-5 | Already restricted under EU RoHS Directive | January 6, 2022 | https://www.federalregister.gov/documents/2021/01/06/2020-28686/decabromodiphenyl-ether-decabde-regulation-of-persistent-bioaccumulative-and-toxic-chemicals-under |
| Hexachlorobutadiene (HCBD) | 87-68-3 | March 8, 2021 | https://www.federalregister.gov/documents/2021/01/06/2020-28693/hexachlorobutadiene-hcbd-regulation-of-persistent-bioaccumulative-and-toxic-chemicals-under-tsca | |
| Pentachlorothiophenol (PCTP) | 133-49-3 | January 6, 2022 | https://www.federalregister.gov/documents/2021/01/06/2020-28689/pentachlorothiophenol-pctp-regulation-of-persistent-bioaccumulative-and-toxic-chemicals-under-tsca | |
| Phenol, Isopropylated Phosphate (3:1) (PIP 3:1) | 68937-41-7 | Flame retardant in flexible polyurethane foam in consumer products, lubricant, hydraulic fluid. | March 8, 2021 | https://www.federalregister.gov/documents/2021/01/06/2020-28692/phenol-isopropylated-phosphate-31-pip-31-regulation-of-persistent-bioaccumulative-and-toxic |
One of the other restricted substances (decaBDA) is already restricted under the EU RoHS Directive and should not be an issue for EEE products that are RoHS compliant.
Several of the substances have restriction dates that vary depending on the application, therefore manufacturers should check the published final rules for their specific applications.
Impact on EEE Manufacturers
Of the five restricted substances, PIP 3:1 is the highest risk for EEE manufacturers. Products with motors or other moving parts that require lubrication are a risk of containing the substances. Parts made of polyurethane foam or PVC (such as wire sheathing) should also be investigated with a request to the supplier. Additional information about other applications may emerge over the next couple months as manufacturers enquire with their supply chains. However, the March 8th deadline to identify components that contain PIP 3:1 and re-design the products to comply is not realistic.