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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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

Biodegradation in water: screening tests

Currently viewing:

Administrative data

Link to relevant study record(s)

Referenceopen allclose all

Endpoint:
biodegradation in water: inherent biodegradability
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
guideline study with acceptable restrictions
Remarks:
non GLP study
Qualifier:
according to guideline
Guideline:
OECD Guideline 302 C (Inherent Biodegradability: Modified MITI Test (II))
GLP compliance:
no
Oxygen conditions:
aerobic
Inoculum or test system:
activated sludge, non-adapted
Details on inoculum:
Fresh activated, non-adapted municipal sewage. Temperature of incubation 21 +/- 1°C
Duration of test (contact time):
28 d
Initial conc.:
30 mg/L
Based on:
test mat.
Parameter:
% degradation (O2 consumption)
Value:
43
Sampling time:
28 d
Details on results:
43% after 28 days
Parameter:
BOD5
Value:
ca. 1 other: mg/l
Results with reference substance:
77% biodegradation of aniline after 4 days.

Under these test conditions, 4,4'-MDA showed some degradation (43%) after 28 days.

Validity criteria fulfilled:
yes
Interpretation of results:
inherently biodegradable, fulfilling specific criteria
Endpoint:
biodegradation in water: ready biodegradability
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
guideline study with acceptable restrictions
Qualifier:
according to guideline
Guideline:
OECD Guideline 301 F (Ready Biodegradability: Manometric Respirometry Test)
GLP compliance:
not specified
Inoculum or test system:
activated sludge (adaptation not specified)
Details on inoculum:
Sewage sludge from sewage treatment plant of Kurume City, Japan. Sampled June 12, 1993.
Mixed liquor suspended solids (MLSS) =1940 mg/l
Duration of test (contact time):
28 d
Initial conc.:
100 mg/L
Based on:
other: Activated sludge concentration used in test = 30mg MLSS/litre
Details on study design:
At the end of the test pH, DOC and residual amount (by HPLC of the solution) of MDA measured.
Experiment done in triplicate.
Test temperature 25 +/- 1 °C
Reference substance:
aniline
Parameter:
other: BOD & residual amount
Value:
0
Sampling time:
28 d
Remarks on result:
other: 1st & 2nd replicate
Parameter:
% degradation (DOC removal)
Value:
0
Sampling time:
28 d
Remarks on result:
other: 1st & 2nd replicate
Parameter:
other: BOD
Value:
19
Sampling time:
28 d
Remarks on result:
other: 3rd replicate
Parameter:
% degradation (DOC removal)
Value:
34
Sampling time:
28 d
Remarks on result:
other: 3rd replicate
Parameter:
other: residue analysis
Value:
37
Sampling time:
28 d
Remarks on result:
other: 3rd replicate
Details on results:
After 28 d, two of three replicates gave 0% biodegradation by BOD, DOC and residue analysis.
After 28 d, in the third replicate there was some biodegradability of 19% by BOD, 34% by DOC and 37% by residue analysis.
Parameter:
BOD5
Value:
ca. 0 other: mg.oxygen
Results with reference substance:
Aniline gave 49.6, 64.4, 67.7 and 69.5mg BOD after 7, 14, 21 and 28 days respectively.

MDA is not readily biodegradable but there is the possibility that MDA may be inherently biodegradable.

Interpretation of results:
other: not readily biodegradable
Conclusions:
MDA is not readily biodegradable.
Endpoint:
biodegradation in water: ready biodegradability
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to guideline
Guideline:
OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)
GLP compliance:
yes (incl. QA statement)
Oxygen conditions:
aerobic
Inoculum or test system:
activated sludge, domestic, non-adapted
Details on inoculum:
Municipal activated sludge from the wastewater treatment plant Mannheim/Baden Württemberg (Germany) was collected on 06 July 2007 from the aeration tank of the plant and aerated in the laboratory until further use. A suitable aliquot of the activated sludge suspension was sieved using a finely woven mesh with a mesh size of about 1 mm. After settling, the supernatant was discarded and the sludge suspension was filled up with tap water. This washing procedure was repeated three times. The suspended solids concentration of the resulting sludge suspension will be determined, and a suitable portion was used to inoculate the mineral medium at a final suspended solids concentration of 30 mg/L. The inoculum was pre-adapted to the test conditions by stirring and aeration with CO2-free air at the test temperature for about five days. After this adaptation period, the inoculated mineral medium (1.5 L) was dispensed into the various test vessels.

Reason for the choice of the biological test system: The test guideline recommends the usage of activated sludge from a wastewater treatment plant, treating municipal sewage.
Duration of test (contact time):
28 d
Initial conc.:
ca. 500 µg/L
Based on:
other: corresponding to a total radioactivity of about 11 microCi in the test assay.
Parameter followed for biodegradation estimation:
radiochem. meas.
Details on study design:
Test temperature 22+/-2 degree C
Reference substance:
aniline
Parameter:
% degradation (radiochem. meas.)
Value:
46
St. dev.:
3.96
Sampling time:
28 d
Details on results:
46% biodegradation after exposure of 28 days
53% (standard deviation +/-3.54%) after exposure of 63 days.
Parameter:
BOD5
Value:
other: unknown
Results with reference substance:
66% degradation after 14 days (%CO2/ThCO2)

The test substance was partly or moderately biodegradable. The study was based on OECD Guideline 301B and measured the evolution of CO2 to determine the degree of biodegradation. Therefore, no BOD was determined.

Validity criteria fulfilled:
yes
Interpretation of results:
not readily biodegradable

Description of key information

On the basis of available biodegradation tests it is not possible to conclude that the substance is biodegraded under environmental conditions.

Key value for chemical safety assessment

Additional information

Results from the ready biodegradation studies clearly indicate that MDA is not readily biodegradable. In the Schwarz (2009) study 0.5mg/l radiolabeled MDA was used in the OECD 301B test. At this very low concentration of test substance and where inhibition of the microbial population would not be expected, only 46% biodegradation was recorded after 28 days exposure. The Yakabe (1994) study confirmed that MDA is not readily biodegradable in the OCED 301F test.


 


In the Caspers et al (1986) study using activated sludge from a predominantly municipal source, the inherent biodegradation of MDA was found to be only 43% after 28 days. In a further inherent biodegradation study (BASF, 1988), using activated sludge from an industrial wastewater treatment plant, MDA was found to undergo 95% degradation after 14 days, and 97% after 21 days.


 


A Coupled Units Test (OECD 303A, Baumann 1986) with activated sludge produced from a mixed inoculum (secondary effluent, Rhine-water, suspension of garden soil) with an adaption phase of 25 days indicated only 6.5% biodegradation after 34 days.


 


These results clearly show that 4,4'-MDA is not readily biodegradable and fulfills the criteria for inherent biodegradation only if an adapted industrial inoculum is used. From the Coupled Units Test it can be deduced that an adaptation time of 25 days is not sufficient. Therefore 4,4'-MDA has to be considered as inherently biodegradable in industrial wastewater treatment plants (WWTPs) only. Degradation in municipal WWTPs cannot be deduced from these results.


A publication of Mei et al. 2015 assessed the biodegradation potential of MDA in experimental studies according to 4 different guidelines and found the test item readily biodegradable in most of the tests, due to missing information these studies were rated as reliable with restriction. Studies with a higher reliability and complete documentation contradict these results.


 


On the basis of available biodegradation tests it is not possible to conclude that the substance is biodegraded under environmental conditions.