Registration Dossier

Data platform availability banner - registered substances factsheets

Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Environmental fate & pathways

Phototransformation in air

Currently viewing:

Administrative data

Link to relevant study record(s)

Reference
Endpoint:
phototransformation in air
Type of information:
(Q)SAR
Adequacy of study:
key study
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
Remarks:
As the substance is a tertiary amine, the estimation may be highly uncertain.
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)
AOP v1.92

3. SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL
See section 'Test Material'.

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

5. APPLICABILITY DOMAIN
See attached QPRF.

6. ADEQUACY OF THE RESULT
- The model is scientifically valid (see attached QMRF).
- The model estimates the phototransformation in air for the uncharged molecule at 25°C. This information is not required under REACH, but can be used in environmental exposure assessment regarding environmental fate (see also attached QPRF).
- See attached QPRF for reliability assessment.
Qualifier:
no guideline followed
Principles of method if other than guideline:
Calculation using AOPWIN v1.92
GLP compliance:
no
Estimation method (if used):
PHOTOCHEMICAL REACTION WITH OH RADICALS
- Concentration of OH radicals: 500000 radicals/cm³
- Temperature for which rate constant was calculated: 25 °C
- Computer programme: SRC AOP v1.92
- Calculated t 1/2 is based on a 24 h day
Key result
DT50:
3.624 h
Test condition:
half-life calculated for the following conditions: sensitizer for indirect photolysis: OH; 0.5 E06 OH/cm³, 24h day
Remarks on result:
other: The substance is in the applicability domain of the model.
Key result
Reaction with:
OH radicals
Rate constant:
0 cm³ molecule-1 s-1
Remarks on result:
other: The substance is in the applicability domain of the model.

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

Hydrogen Abstraction      

 40.2395 E-12 cm3/molecule-sec

Reaction with N, S and -OH

 66.0000 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

 106.2395 E-12 cm3/molecule-sec

HALF-LIFE

    0.151 Days (24-hr day; 0.5E6 OH/cm3)

HALF-LIFE

    3.624 Hrs

Estimate refers to the uncharged molecule.

Description of key information

After evaporation or exposure to the air, the substance will be rapidly degraded by photochemical processes.

Key value for chemical safety assessment

Half-life in air:
3.62 h
Degradation rate constant with OH radicals:
0 cm³ molecule-1 d-1

Additional information

QSAR-disclaimer:

In Article 13 of Regulation (EC) No 1907/2006, it is laid down that information on intrinsic properties of substances may be generated by means other than tests, provided that the conditions set out in Annex XI (of the same Regulation) are met. 

According to Annex XI of Regulation (EC) No 1907/2006 (Q)SAR results can be used if (1) the scientific validity of the (Q)SAR model has been established, (2) the substance falls within the applicability domain of the (Q)SAR model, (3) the results are adequate for the purpose of classification and labeling and/or risk assessment and (4) adequate and reliable documentation of the applied method is provided.

For the assessment of Tributylamine (CAS 102-82-9) (Q)SAR results were used for phototransformation in air. The criteria listed in Annex XI of Regulation (EC) No 1907/2006 are considered to be adequately fulfilled and therefore the endpoint(s) sufficiently covered and suitable for risk assessment.

Therefore, further experimental studies on phototransformation in air are not provided.

 

Assessment:

However, photodegradation was calculated for Tributylamine (CAS 102-82-9) with AOPWIN v1.92, implemented in EPISuite v4.11. Based on an estimated OH-radical-rate constant of 106.24E-12 cm³/molecule-sec, the half-life was calculated to be 3.6 h; for this calculation a 24 -hour day as well as a sensitizer-concentration (OH-radicals) of 5E+06 molecules/cm³ were assumed (BASF SE, 2018).