Rhamnolipids: fermentation products of glucose with Pseudomonas putida, Pseudomonadaceae

PBT assessment

PBT assessment: overall result

PBT status:

the substance is not PBT / vPvB

Justification:

The criteria given in the “Guidance on information requirements and chemical safety assessment, chapter R.11: PBT Assessment” (ECHA, 2014c) are used as information to decide whether the target substance Rhamnolipids: fermentation products of glucose with Pseudomonas bacteria, and the source substance employed may potentially fulfil the PBT or vPvB criteria.

Persistence Assessment

Based on the available data, Rhamnolipids: fermentation products of glucose with Pseudomonas bacteria is readily biodegradable based on experimental data, as a mean degradation rate of 106 % was observed after 28 days in a ready biodegradability assay. Thus, as a conclusion can be reached based on available information and in the absence of additional information to make a definitive determination, it may be presumed that the substance is not "persistent” (potentially “P”) and potentially very persistent (potentially “vP”).

Bioaccumulation Assessment

The bioaccumulation potential of Rhamnolipids: fermentation products of glucose with Pseudomonas bacteria is expected to be high. This assumption is based on the following:

The screening-level determinations that the substance is not bioaccumulative ("B") based on an experimentally-determined log Kow of -0.247, which is substantially below the screening criterion (log Kow >= 4.5) for both “B” and “vB”.

Toxicity assessment

The determinations that the substance is “not CMR” and “not T, R48” or “Xn, R48” under the DSD/DPD classification, and are not carcinogenic (category 1A or 1B), germ cell mutagenic (category 1A or 1B), toxic for reproduction (category 1A, 1B or 2) or exhibit chronic toxicity (STOT-RE category 1 or 2) under the CLP Regulation, are definitive determinations of “not T” with respect to human health endpoints. The short-term screening-level data for aquatic toxicity determined EC50 (daphnids) > 196 mg/L which is > then the cut-off limit for determining T properties (> 0.1 mg/L). An acute toxicity study (OECD 203) test on the effects of Rhamnolipids: fermentation products of glucose with Pseudomonas bacteria on Rare Minnow was conducted. At the end of the test, the cumulative mortalities of the nominal concentration of 10.0 mg/L, 17.8 mg/L, 31. 8 mg/L, 56.2 mg/L and 100 mg/L test groups were 0%, 0%, 0% and 100%, respectively. Hence the effects of the test substance to Rare Minnow described as the 96 h median lethal concentration (LC50), the lowest concentration causing 100% mortality (LC100) and the highest concentration causing 0% mortality are: LC50 75 mg/mL, LC100 mg/L and LC0 56.2 mg/L. Thus, the LC50 (96h) is Rhamnolipids: fermentation products of glucose with Pseudomonas bacteria 75 mg/L. In addition, a guideline study on the toxicity of the substance to a freshwater alga (Pseudokirchneriella subcapitata) was conducted, and from which the 72 h ErC10 and 72 h ErC50 values were derived as >185 mg a.i./LA guideline study on acute toxicity of the substance on Daphnia magna was conducted and the value EC50 (48 h) >196 mg/L was derived. A semi-static reproduction test with Daphnia magna was conducted according to OECD 211 in order to investigate the chronic effects of the test item on daphnids. In the present study, five nominal concentrations (1.05, 3.36, 10.76,

34.42, and 110.13 mg test item (TI)/L, corresponding to 0.95, 3.05, 9.77, 31.25 and 100.0 mg active ingredient (a.i)./L (measured concentrations). The EC10 was determined to be 34.27 mg/L, based on the reproduction.

All together the experimental data indicate that the substance is “presumably not T” with respect to aquatic toxicity.

Therefore, although a complete definitive determination cannot be made with respect to three endpoints (P, vP, and T), screening level criteria indicate that the substance is potentially “P”, potentially “vP”, “not B”, “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 based on screening criteria 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, May 2008, Section R.11.1.2.2, p. 13).The source substance 11 is already registered under Regulation (EC) No 1907/2006 and the PBT/vPvB Assessment as part of the Chemical Safety Assessment (CSA, Annex I) indicated that they are not PBT/vPvB¹.

1 Information is based on the data publically available in the database on registered substances on ECHAs website.