1-butylpyrrolidin-2-one

PBT assessment

PBT assessment: overall result

Reference

Reference 1

Name:

N-Butylpyrrolidone

Type of composition:

boundary composition of the substance

State / form:

liquid

Reference substance:

N-Butylpyrrolidone

Reference 2

Name:

N-Butylpyrrolidone

Type of composition:

legal entity composition of the substance

State / form:

liquid

Related composition:

N-Butylpyrrolidone

Reference substance:

N-Butylpyrrolidone

PBT status:

the substance is not PBT / vPvB

Justification:

Persistency (v / vP properties):

In a Closed Bottle Test according to OECD Guideline 301D (Muckle 2013a), the test compound showed no significant biodegradation and based on this outcome, N-Butylpyrrolidone was assigned as not readily biodegradable. Consecutively, Muckle (2013b) investigated potential inherent biodegradation in a Zahn-Wellens Test following OECD Guideline 302B. Due to the observed long lag-Phase in this study, the standard study duration (28 days) was prolonged to 112 days. After this exposure period, a mean degradation of 81 % was observed. This result confirms that N-Butylpyrrolidone is ultimately biodegradable; after an appropriate lag-Phase a full degradation of the compound is to be expected. In the second study on the substance’s inherent biodegradability (modified MITI Test, OECD 302C) performed by Hammerfahr and Münz (2015), N-Butylpyrrolidone was found to be completely primary biodegradable after a lag phase of four weeks resulting in 100% degradation after 56 days of incubation.

Based on the available biodegradation studies as well as from experience at production site, sufficient biodegradability of N-Butylpyrrolidone is to be expected. It is concluded, that criteria for P / vP properties are not fulfilled for this compound.

Bioaccumulation (B / vB properties):

Due to the low Log Pow value of N-Butylpyrrolidone significant bioaccumulation potential is not to be expected for this compound. The detected Log Pow amounts to 1.265 in a test according to OECD Guideline 117(Johannes, 2013). This result is by far below the level (Log Pow > 4.5) which triggers the necessity of an aquatic bioacccumulation test. The lack of bioaccumulative potential is also confirmed by the low BCF (3.198) which was revealed by QSAR modeling (Chemservice S.A. 2017c). For this purpose, the BCF/BAF assessment tool of US-EPA was used and the calculation was based on the measured Log Pow (1.265). Based on these properties, a relevant bioaccumulation potential of N-Butylpyrrolidone can be ruled out.

Toxicity (T properties):

Taken into account the presented data for aquatic toxicity of N-Butylpyrrolidone, experimental short-term results are available for three trophic levels (i.e. fish, invertebrates and algae). Furthermore, long-term data are available regarding possible effects towards fish (Pimephales promelas; NOEC = 82 mg/L), Daphnia magna (NOEL = 100 mg/L) and algae (NOEC = 40 mg/L). In all tests, N-Butylpyrrolidone demonstrated only a low level of toxicity towards aquatic organisms.

Furthermore, the substance was not mutagenic, reproductive or developmental toxicant in the recent animal studies. The substance did not damage organs in the repeated dose toxicity study (OECD 408). Therefore, criteria for assigning "T" properties are clearly not fulfilled.

Likely routes of exposure:

Due to the intended uses and the low concentrations of N-Butylpyrrolidone direct or indirect release of relevant amounts to the environment are not to be expected.