Methylhydrazine

Distribution modelling

Administrative data

Endpoint:

distribution modelling

Type of information:

(Q)SAR

Adequacy of study:

supporting study

Study period:

not applicable (QSAR)

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

QSAR estimate by an internationally recognized QSAR, within its applicability domain, with correct recognition of the chemical family (hydrazines) and of the compound structure, and based on several experimental data (boiling point, melting point, vapour pressure) which were correctly re-estimated by this QSAR.

Justification for type of information:

QSAR prediction: migrated from IUCLID 5.6

Data source

Reference

Reference Type:

other: QSAR

Title:

EPI Suite Results For CAS 000060-34-4

Author:

Anonymous

Year:

2010

Bibliographic source:

US EPA's Office of Pollution Prevention and Toxics + Syracuse Research Corporation, Estimation Programs Interface (EPI) Suite, v4.00

Materials and methods

Model:

calculation according to Mackay, Level III

Calculation programme:

EPIsuite v4.00

Media:

other: Air - Water - Soil - Sediment

Test material

Test material information

Constituent 1

Reference substance name:

Methylhydrazine

EC Number:

200-471-4

EC Name:

Methylhydrazine

Cas Number:

60-34-4

Molecular formula:

CH6N2

IUPAC Name:

methylhydrazine

Study design

Test substance input data:

QSAR estimation by Level III Fugacity Model, based on following:
- identification data: SMILES= N(N)C, CAS= 000060-34-4 (software recognizes structure, name and ECOSAR Class= hydrazines)
- experimental input: boiling point, melting point, vapour pressure: values as in IUCLID
- direct emissions to air, water and soil at 1000 kg/h each are considered

Results and discussion

Percent distribution in media

Other distribution results:

The total persistence time and the % in each compartment depend on type of emissions (air, water and/or soil).
Degradation half-lives do not depend on emission routes:
- Air: 0.257 h (15 min)
- Water: 360 h (15 days)
- Soil: 720 h (1 month)
- Sediment: 3240 h (>4 months)

Any other information on results incl. tables

coherence of other estimates vs. experimental data:

- boiling point: 59.42°C vs. 87.5°C (8% difference when converted in °K: good)

- melting point: -57.59°C vs. -52.4°C (2% difference when converted in °K: very good)

- vapour pressure: 50 mmHg vs. 63.7 mmHg (27% difference: acceptable)

These data validate the relevance of the estimates.

Applicant's summary and conclusion

Executive summary:

The fugacity has been estimated by QSAR using EPIsuite v4.00.

The estimated half-lives indicate quick degradation in air (15 min), slower but still significant degradation in water (15 days), some persistence in soil (1 month) and a clear persistence in sediment (>4 months).

The total persistence time and the % in each compartment depend on type of emissions (air, water and/or soil). The most likely case would be direct emission to air and water since there is no direct exposure of soil based on UDS for the substance. For 1000 kg/h to air and water, the following results are obtained:

- Air: 0.1%

- Water: 94.6%

- Soil: 5.1%

- Sediment: 0.23%

- Persistence Time: 183 h (<8 days)