Isopropyl benzoate

PBT assessment

PBT assessment: overall result

PBT status:

the substance is not PBT / vPvB

Justification:

The substance exhibited ready biodegradability in CO₂ evolution test; mineralisation of 85% was achieved in 28 days, and the 10-day window was met. Therefore, the substance has been determined to be “not persistent” (“not P”) and “not very persistent” (“not vP”), based on screening criteria. 

Aquatic bioaccumulation testing was not conducted on the substance, and therefore the bioaccumulative properties of the substance cannot be definitively determined. However, the predicted octanol-water partition coefficient (log K_ow) of 2.93 is substantially below the screening criterion (log K_ow≤ 4.5) for the determinations of both “not bioaccumulative” (“not B”) and “not very bioaccumulative” (“not vB”).  Additionally, the substance’s demonstrated rapid biodegradability in the environment indicates that the substance has a low potential for aquatic bioaccumulation; substances that degrade rapidly in the environment “are likely to be rapidly metabolized in organisms” in accordance with ECHA guidance (ECHA, Guidance on information requirements and chemical safety assessment, Chapter R.7C, Endpoint-specific guidance, Section R.7.10.3.4, p. 26, November 2012). Therefore, although a definitive determination has not been made, the substance is considered to be “presumably not B” and “presumably not vB”. 

A definitive determination regarding aquatic toxicity cannot be made, due to the absence of data from long-term aquatic studies. The evaluation of short-term aquatic toxicity tests indicate that the lowest reported toxicity value was the 96-h LC50 of 23 mg/L, based on read across from an acute fish toxicity study of methyl benzoate, a member of a chemical category established for the substance. This LC50 of 23 mg/L is substantially above the definitive criterion of < 0.01 mg/L and the screening criterion of < 0.1 mg/L, below which a substance is considered to be toxic with respect to aquatic endpoints. Thus, based on screening criteria, the substance is “presumably not toxic” (“presumably not T”) with respect to aquatic organisms. The substance does not exhibit the properties of a carcinogenic, mutagenic or reproductive toxicant (CMR), nor does the substance exhibit specific target organ toxicity in a repeated-dose study (STOT-RE). These results provide a definitive determination that the substance is “not toxic” (“not T”) with respect to mammalian endpoints. Therefore, the substance is “not T” based upon the available information for both aquatic toxicity and mammalian toxicity endpoints.

Although a complete definitive determination cannot be made with respect to the bioaccumulation endpoint, it has been shown by definitive data that the substance is “not P”, “not vP”, “presumably not B”, “presumably not vB” and “not T”. It is not necessary to have definitive criteria for all five endpoints to make the determinations as to whether the substance is “not PBT” and “not vPvB”. The determination only requires that “each of the three properties persistency, bioaccumulation and toxicity need to be considered in conjunction” (Chapter R.11, “PBT Assessment”, Guidance on information requirements and chemical safety assessment, ECHA, November 2012, Section R.11.1.2.2, p. 15). In summary, based on data available to date, the substance is “not PBT” (not P, presumably not B, and not T) and is “not vPvB” (not vP, presumably not vB).