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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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

Adsorption / desorption

Currently viewing:

Administrative data

Link to relevant study record(s)

Referenceopen allclose all

Endpoint:
adsorption / desorption: screening
Remarks:
Calculation of log Koc for ionized molecule
Type of information:
calculation (if not (Q)SAR)
Remarks:
Estimated by calculation
Adequacy of study:
key study
Study period:
no data
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
accepted calculation method
Qualifier:
no guideline followed
Principles of method if other than guideline:
Calculation method determining the Koc for charged molecules according to Franco & Trapp (2008)
GLP compliance:
no
Type of method:
other: calculation of log Koc for ionized molecule
Media:
soil
Type:
Koc
Value:
42 dimensionless
Type:
log Koc
Value:
1.63 dimensionless

The data refer to the charged molecule.

Validity criteria fulfilled:
not specified
Conclusions:
Adsorption of maleic acid to the soild soil phase is not expected.
Executive summary:

Using a pH-corrected logKoc calculation according to a publication by Franco & Trapp (2008) a Koc of 42 and a log koc of 1.63 were determined for maleic acid. This calculation used a pKa of 1.83 and a logPow of -0.48 (both related to maleic acid) as input parameters. Due to the results, adsorption of the substance to the soild soil phase is not expected.

Endpoint:
adsorption / desorption: screening
Remarks:
Calculation of log Koc for ionized molecule
Type of information:
read-across from supporting substance (structural analogue or surrogate)
Remarks:
Estimated by calculation
Adequacy of study:
key study
Justification for type of information:
Upon contact with water, maleic anhydride hydrolyses rapidly (DT50 = 0.3 min), forming maleic acid (Bunton et al., 1963). This constitutes almost instantaneous abiotic degradation, particularly in comparison to the residence/transport times in the wastewater stream. Therefore, both sewage treatment plants and subsequently surface waters will be exposed to maleic acid (if at all) instead of maleic anhydride. Accordingly, read-across of environmental effects from maleic acid to maleic anhydride is justified.
Reason / purpose for cross-reference:
read-across source
Type:
Koc
Value:
42 dimensionless
Type:
log Koc
Value:
1.63 dimensionless

The data refer to the charged molecule.

Validity criteria fulfilled:
not specified
Conclusions:
Adsorption of maleic acid to the soild soil phase is not expected.
Executive summary:

Using a pH-corrected logKoc calculation according to a publication by Franco & Trapp (2008) a Koc of 42 and a log koc of 1.63 were determined for maleic acid. This calculation used a pKa of 1.83 and a logPow of -0.48 (both related to maleic acid) as input parameters. Due to the results, adsorption of the substance to the soild soil phase is not expected.

This information for maleic acid is used in a read-across approach in the assessment of the target substance maleic anhydride.

Upon contact with water, maleic anhydride hydrolyses rapidly (DT50 = 0.3 min), forming maleic acid (Bunton et al., 1963). Therefore, read-across from maleic acid to maleic anhydride is justified.

Endpoint:
adsorption / desorption: screening
Remarks:
adsorption
Type of information:
(Q)SAR
Adequacy of study:
supporting study
Study period:
no data
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
accepted calculation method
Qualifier:
no guideline required
Principles of method if other than guideline:
calculated
GLP compliance:
no
Type of method:
other: model calculation
Media:
soil
Type:
Koc
Value:
6.314 dimensionless
Type:
log Koc
Value:
0.8 dimensionless
Note: KOC may be sensitive to pH!
Validity criteria fulfilled:
not applicable
Conclusions:
No adsorption to soil is expected.
Executive summary:

The log Koc of 0.8, calculated by means of SRC PCKOCWIN (v1.66, 2009)

for the uncharged molecule of maleic acid suggests that the substance will probably not adsorb to soil particles.
Endpoint:
adsorption / desorption: screening
Remarks:
adsorption
Type of information:
read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
supporting study
Justification for type of information:
Upon contact with water, maleic anhydride hydrolyses rapidly (DT50 = 0.3 min), forming maleic acid (Bunton et al., 1963). This constitutes almost instantaneous abiotic degradation, particularly in comparison to the residence/transport times in the wastewater stream. Therefore, both sewage treatment plants and subsequently surface waters will be exposed to maleic acid (if at all) instead of maleic anhydride. Accordingly, read-across of environmental effects from maleic acid to maleic anhydride is justified.
Reason / purpose for cross-reference:
read-across source
Type:
Koc
Value:
6.314 dimensionless
Type:
log Koc
Value:
0.8 dimensionless
Note: KOC may be sensitive to pH!
Validity criteria fulfilled:
not applicable
Conclusions:
No adsorption to soil is expected.
Executive summary:

The log Koc of 0.8, calculated by means of SRC PCKOCWIN (v1.66, 2009)

for the uncharged molecule of maleic acid suggests that the substance will probably not adsorb to soil particles.

This information for maleic acid is used in a read-across approach in the assessment of the target substance maleic anhydride.

Upon contact with water, maleic anhydride hydrolyses rapidly (DT50 = 0.3 min), forming maleic acid. Therefore, read-across from maleic acid to maleic anhydride is justified.

Description of key information

Adsorption to the solid soil phase is not expected.

Key value for chemical safety assessment

Koc at 20 °C:
42

Additional information

In the presence of water, maleic anhydride rapidly hydrolyzes forming maleic acid (DT50 = 0.3 min, Bunton et al., 1963). The log Koc of 0.8, calculated for the uncharged molecule of maleic acid suggests that the substance will probably not adsorb to soil particles. However, the pKa value calculated for maleic acid indicates that the molecule will primarily exist as an anion in the environment. The PCKOC-model may miscalculate adsorption to organic carbon since the ionic structure of the substance is not considered in the calculation. Therefore, a corrected logKoc based on the degree of ionisation and the formula of Franco & Trapp (2008) was used for correction. The degree of ionisation is calculated based on the following formula:

 

% ionised = 100/(1 +10(pka-pH)). (See also IUCLID chapter 4.21)

 

Using a pH-corrected logKoc calculation according to a publication by Franco & Trapp (2008) a Koc of 42 and a log koc of 1.63 were determined for maleic acid. This calculation used a pKa of 1.83 and a logPow of -0.48 (both related to maleic acid) as input parameters. Due to the results, adsorption of the substance to the soild soil phase is not expected.