7a-ethyldihydro-1H,3H,5H-oxazolo[3,4-c]oxazole

PBT assessment

PBT assessment: overall result

PBT status:

the substance is not PBT / vPvB

Justification:

The available evidence on degradation, bioaccumulation potential, and toxicity for 7a-ethyldihydro-

1H,3H,5H-oxazolo[3,4-c]-oxazole (CS-1246) indicates that the screening criteria for persistence (P),

bioaccumulation potential (B), and toxicity (T) are not met. Based on the information described below

for the relevant endpoints, CS-1246 is considered as not PBT/vPvB.

Table 45: Summary conclusion on PBT or vPvB properties

Constituent	P/vP	B/vB	T
7a-ethyldihydro- 1H,3H,5H-oxazolo[3,4-c]- oxazole EC no. 231-810-4 CAS no. 7747-35-5	Rapidly hydrolyzes (halflife <4 hours at pH 4, 7, and 9 at 25°C (The Dow Chemical Company, 2003) Conclusion: Not P/vP based on definitive criteria.	Measured log Pow is -0.32 at 25°C (Sudworth, 2007) Conclusion: Not B/vB based on screening criteria.	LC50/EC50 values96 hour= 130 mg/LLepomis macrochirus(The Dow Chemical Company, 1982) LC50/EC5048 hour= 16.9 mg/L forDaphnia magna(The Dow Chemical Company, 2007) EC5072 hr.= 1.08 mg/L NOEL72 hr.= 0.513 mg/L Selenastrum capricornutum (The Dow Chemical Company, 2002) Conclusion: Not T based on screening criteria
Degradation Product	P/vP	B/vB	T
2-amino-2-ethyl-1,3- propanediol CAS no. 115-70-8	AEPD degraded >90% in 7 days in inherent biodegradation test (The Angus Chemical Company, 1996) Conclusion: Not P/vP based on screening criteria.	Estimated log Pow is –0.60 (KOWWIN version 1.67) Conclusion: Not B/vB based on screening criteria.	LC50/EC50 values96 hour= 460 mg/L Leuciscus idus melanotus L. (Institut für gewerblische Wasserwirtschaft und Luftreinhaltung e.V.,1991) This measured value is consistent with predicted ecotoxicity endpoints which are greater than the toxicity threshold for T. Predicted acute toxicity LC50/EC50values for algae, water fleas, and fish range from 8 to 770 mg/L (ECOSAR version 1.00) Conclusion: Not T based on screening criteria.
Formaldehyde CAS no. 50-00-0	Formaldehyde is readily biodegradable, with 91% biodegradation based on BOD in 28 days in OECD 301C test (National Institute of Technology and Evaluation, Japan (1989) Conclusion: Not P/vP based on screening criteria	Log Pow is 0.35 at 25°C. (J. Sangster.1989. Octanol- Water Partition Coefficients of Simple Organic Compounds. J. Phys. Chem. Ref. Data, 18 (3), 1163) Conclusion: Not B/vB based on screening criteria.	Alga is most sensitive species for acute toxicity of formaldehyde: Desmodesmus subspicatus, 72h-ErC50of 4.89 mg/L (Eisenträger A, Dott W, Klein J, Hahn S (2003) Comparative studies on algal toxicity testing using fluorometric microplate and Erlenmeyer flask growthinhibition assays. Ecotoxicol Environ Safety 54: 346-354 Conclusion: Not T based on screening criteria.