Reaction Mass of Triphenylthiophosphate and Tertiary Butylated Phenyl Derivatives Proposed as SVHC

Reason for Proposal

The primary reason for the Netherlands' proposal is the substance's classification as persistent, bioaccumulative, and toxic (PBT). According to the Annex XV report, the substance and its constituent, triphenylthiophosphate, demonstrate significant environmental persistence and potential for bioaccumulation in aquatic organisms. The classification is based on criteria set out in Article 57(d) of the REACH Regulation (EC) No 1907/2006.

Key Findings from the Annex XV Report

The Annex XV report provides comprehensive data on the substance's properties and potential risks:

• Persistence: The substance shows a high degree of persistence in the environment. Simulation tests conducted with triphenylthiophosphate (TPPT) in fresh surface water revealed no significant degradation over a period of 61 days. Further hydrolysis tests indicated a half-life of up to 278 days at pH 7 and 12°C, which meets the criteria for being classified as both persistent (P) and very persistent (vP).
• Bioaccumulation: Studies on aquatic organisms, specifically carp, exposed to the substance showed bioconcentration factors (BCF) exceeding 2000, indicating a high potential for bioaccumulation. The measured log Kow (octanol-water partition coefficient) value of 5.0 further supports this classification.
• Toxicity: The substance also exhibits significant toxicity. Early life stage tests with rainbow trout resulted in a no observed effect concentration (NOEC) of 1.7 µg/L, which is well below the threshold of 10 µg/L, confirming its classification as toxic (T).

Uses and Potential Risks

The "Reaction mass of: triphenylthiophosphate and tertiary butylated phenyl derivatives" is used in various industrial applications, including as additives in lubricants and hydraulic fluids. While these applications are crucial for performance, the persistent nature of the substance means it can remain in the environment for extended periods, posing long-term risks to aquatic life and possibly accumulating in the food chain.

Environmental and Health Concerns

The PBT properties of the substance raise significant environmental and health concerns. Persistent substances do not break down easily and can spread across large geographic areas, leading to widespread exposure. Bioaccumulative substances accumulate in the tissues of living organisms, potentially leading to toxic effects over time. The toxicity observed in aquatic life stages suggests that there could be broader implications for ecosystem health and biodiversity.