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Adsorption / desorption

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Endpoint:
adsorption / desorption: screening
Remarks:
adsorption
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
Principles of method if other than guideline:
QSAR estimation by KOCWIN v2.00, using two methods (MCI and log Kow) 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
GLP compliance:
no
Remarks:
QSAR
Type of method:
other: QSAR
Media:
soil
Computational methods:
QSAR methods: MCI and equation using log Kow
Type:
log Koc
Value:
1.124
Remarks on result:
other: MCI method (QSAR)
Type:
log Koc
Value:
0.323
Remarks on result:
other: Kow method (QSAR)
Validity criteria fulfilled:
not applicable
Executive summary:

The soil adsorption coefficient of MMH was estimated by QSAR by KOCWIN v2.00 inside EPIsuite v4.00, as Log Koc = 1.124 (using MCI method) or 0.323 (based on log Kow). Therefore adsorption is negligible and enables high mobility in soils.

The relevance of these estimates is confirmed by the coherence of three other estimates with available experimental data.

Endpoint:
adsorption / desorption: screening
Data waiving:
study scientifically not necessary / other information available
Justification for data waiving:
the study does not need to be conducted because the physicochemical properties of the substance indicate that it can be expected to have a low potential for adsorption

Description of key information

In agreement with Annex VIII point 9.3.1, the study does not need to be conducted because the substance can be expected to have a negligible potential for adsorption due to its negative experimental log Kow (-1.05) and its extremely high water solubility.

Nevertheless, the soil adsorption coefficient of MMH was estimated as a supportive information, using QSAR by the mean of KOCWIN v2.00 inside EPIsuite v4.00. The following outputs have been found for the substance:

- Log Koc = 1.124 (using MCI method)

- Log Koc = 0.323 (based on log Kow).

Therefore adsorption is negligible and enables high mobility in soils.

The relevance of these estimates is confirmed by the coherence of three other estimates with available experimental data.

Key value for chemical safety assessment

Koc at 20 °C:
1.124

Additional information