2-dimethylaminoethanol

Phototransformation in air

Link to relevant study record(s)

Reference

Endpoint:

phototransformation in air

Type of information:

(Q)SAR

Adequacy of study:

key study

Study period:

2019-04-10

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
CN(C)CCO, See also 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).
- See attached QPRF for reliability assessment.

Guideline:

other:

Version / remarks:

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:

CN(C)CCO

Estimation method (if used):

Photochemical reaction with OH radicals
Concentration of OH radicals: 0.5 x E6,
assuming a 24-hour day
Degradation rate constant: 65.5296 E-12 cm3/molecule-sec
Temperature for which rate constant was calculated: 25°C

Light source:

sunlight

Reference substance:

no

DT50:

0.192 d

Reaction with:

OH radicals

Rate constant:

0 cm³ molecule-1 s-1

SMILES : CN(C)CCO

CHEM   :

MOL FOR: C4 H11 N1 O1

MOL WT : 89.14

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

Hydrogen Abstraction       =  17.2345 E-12 cm3/molecule-sec

Reaction with N, S and -OH =  66.1400 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 =  83.3745 E-12 cm3/molecule-sec

  HALF-LIFE =     0.192 Days (24-hr day; 0.5E6 OH/cm3)

  HALF-LIFE =     4.618 Hrs

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

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

              (ONLY Olefins and Acetylenes are Estimated)

Experimental Database Structure Match:

 Chem Name :  2-Dimethylaminoethanol

 CAS Number:  000108-01-0

 Exper OH rate constant   :  90  E-12  cm3/molecule-sec

   Exper OH Reference:  ATKINSON,R (1989)

 Exper Ozone rate constant:  ---  cm3/molecule-sec

 Exper NO3 rate constant  :  ---  cm3/molecule-sec

Validity criteria fulfilled:

yes

Conclusions:

QSAR-Calculation with EPI-WIN tool of US-EPA (AOPWin, v1.92) was performed. For dimethylaminoethanol an overall OH rate constant (gas-phase reaction constant) of 83.3745 x E-12 cm3/molecules-sec and a half-life of 0.192 days (4.618 hours) was calculated. No ozone reaction as well as no nitrate radical reaction is estimated for the substance. 

Executive summary:

QSAR-Calculation with EPI-WIN tool of US-EPA (AOPWin, v1.92) was performed (Chemservice S.A., 2019). For dimethylaminoethanol an overall OH rate constant (gas-phase reaction constant) of 83.3745 x E-12 cm3/molecules-sec and a half-life of 0.192 days (4.618 hours) was calculated. No ozone reaction as well as no nitrate radical reaction is estimated for the substance. 

Description of key information

Degradation rate constant with OH radicals: 83.3745 x E-12 cm³/molecules-sec (Chemservice S.A., 2010, updated 2019).

Key value for chemical safety assessment

Half-life in air:

4.618 h

Degradation rate constant with OH radicals:

0 cm³ molecule-1 s-1

Additional information

The tropospheric half-life of 2 -dimethylaminoethanol was estimated based on a calculation with the scientifically accepted EPI-WIN software AOPWINv1.92 (Chemservice S.A., 2010, updated 2019). The calculation indicates a rapid degradation of the test substance when potentially entering the atmosphere, indicated by a half-life of 0.192 days (4.618 hours) for a 24 h day and 0.128 days (1.539 hours) for a 12 h day. However, the worst case value of 4.618 hours for the 24 h day is included as the key value for chemical safety assessment. It is not expected that the substance will accumulate in the air or be transported in the gaseous phase over long distances. The gas-phase reaction constant (also called overall OH rate constant) is calculated as 83.3745 x E-12 cm³/molecules-sec. For 2 -dimethylaminoethanol no nitrate as well as no ozone reaction is expected.