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Environmental fate & pathways

Phototransformation in air

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Reference
Endpoint:
phototransformation in air
Type of information:
(Q)SAR
Adequacy of study:
key study
Study period:
2019-03-20
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
results derived from a valid (Q)SAR model and falling into its applicability domain, with adequate and reliable documentation / justification
Justification for type of information:
1. SOFTWARE
Estimation Programs Interface (EPI) Suite for Microsoft Windows, v4.11 (US EPA, 2012)

2. MODEL (incl. version number)
AOPWIN v1.92a

3. SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL
O=C1CCCN1, See also section 'Test Material'.

4. SCIENTIFIC VALIDITY OF THE (Q)SAR MODEL
See attached QMRF.

5. APPLICABILITY DOMAIN
See attached QPRF.
Guideline:
other: REACH Guidance on QSARs R.6
Principles of method if other than guideline:
- Software tool(s) used including version: EpiSuite v4.11
- Model(s) used: AOPWIN v1.92a
- Model description: see field ''Attached justification'
- Justification of QSAR prediction: see field 'Attached justification'
Specific details on test material used for the study:
O=C(NCC1)C1
Estimation method (if used):
Photochemical reaction with OH radicals
Concentration of OH radicals: 1.5 x E6
Degradation rate constant: 11.9334 E-12 cm3/molecule-sec
Temperature for which rate constant was calculated: 25 °C
Assuming a 12-hour day
Light source:
sunlight
DT50:
0.896 d
Test condition:
QSAR calculation
Reaction with:
OH radicals
Rate constant:
11.933 cm³ molecule-1 s-1

SMILES : O=C(NCC1)C1

CHEM   : 2-Pyrrolidinone

MOL FOR: C4 H7 N1 O1

MOL WT : 85.11

------------------- SUMMARY (AOP v1.92): HYDROXYL RADICALS (25 deg C) --------

Hydrogen Abstraction       =   6.4334 E-12 cm3/molecule-sec

Reaction with N, S and -OH =   5.5000 E-12 cm3/molecule-sec

Addition to Triple Bonds   =   0.0000 E-12 cm3/molecule-sec

Addition to Olefinic Bonds =   0.0000 E-12 cm3/molecule-sec

Addition to Aromatic Rings =   0.0000 E-12 cm3/molecule-sec

Addition to Fused Rings    =   0.0000 E-12 cm3/molecule-sec

  OVERALL OH Rate Constant =  11.9334 E-12 cm3/molecule-sec

  HALF-LIFE =     0.896 Days (12-hr day; 1.5E6 OH/cm3)

  HALF-LIFE =    10.756 Hrs

------------------- SUMMARY (AOP v1.91): OZONE REACTION (25 deg C) -----------

              ******  NO OZONE REACTION ESTIMATION ******

              (ONLY Olefins and Acetylenes are Estimated)

Experimental Database:  NO Structure Matches

Validity criteria fulfilled:
yes
Conclusions:
Rapid degradation of the test substance in air is estimated by QSAR (DT50 = 10.76 hours)
Executive summary:

QSAR - Calculation with EPI-WIN tool of US-EPA (AOPWIN v1.92) was performed. For 2 -pyrrolidone an overall OH rate constant (gas-phase reaction constant) of 11.9334 E-12 cm3/molecule-sec and a half-life of 0.896 days (10.756 hours; based on a 12 -h day) was calculated. No ozone reaction as well as no nitrate reaction is estimated for the desired chemical.

Description of key information

The tropospheric half-life of 2-Pyrrolidone was estimated based on a calculation with the scientifically accepted EPI-Win software tool of US-EPA (AOP-Win, v.1.92; Chemservice S.A., 2010, updated 2019). In the atmosphere 2-pyrrolidone is expected to be indirectly photodegraded with a half life of ca. 10.8 hours. The calculation indicates a rapid degradation of 2-pyrrolidone when potentially entering the atmosphere. It is not to be expected that 2-pyrrolidone will accumulate in the air or be transported in the gaseous phase over long distances. Hence, air will not be an environmental compartment of concern for the compound.

Key value for chemical safety assessment

Half-life in air:
10.8 h

Additional information