Maleic anhydride

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2010-04-08 - 2010-06-18

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)

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch number of test material: Batch No. LPMS3A1015
- Expiration date of the lot/batch: Oct. 2013

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: ambient (18-36°C)

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure): Community Sewerage Plant Bharath Electronics Limted, Vidyaranyapuram, Bangalore, INDIA
- Laboratory culture: The effluent was allowed to settle for one hour and decanted. The decanted effluent was then used in the test
- Method of cultivation: The bacterial population in the inoculum was determined as colony forming units (CFU/mL) by diluting the inoculum up to 10-4 dilution and then plating on nutrient agar plates

Duration of test (contact time):

29 d

Initial conc.:

33.33 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

TEST CONDITIONS
- Composition of medium: as described in the guideline

TEST SYSTEM
- Culturing apparatus: Conical flasks 5 L capacity each fitted with an aeration tube reaching nearly to the bottom of the flask and an outlet
- Number of culture flasks/concentration: 4
- Method used to create aerobic conditions: continous gas flow
- Details of trap for CO2 and volatile organics if used: The amount of CO2 produced was calculated from the amount of base remaining in the absorption bottle. When 0.0125 M Ba(OH)2 was used as the absorbent, the amount remaining is assessed by titrating with 0.05 M HCl (thus, 50 mL HCl would be needed to titrate 100 mL Ba(OH)2).

SAMPLING
- Sampling frequency: every 3-4 days

CONTROL AND BLANK SYSTEM
- Inoculum blank: yes
- Toxicity control: yes
- Other: inhibition control

Reference substance:

benzoic acid, sodium salt

Parameter:

% degradation (CO2 evolution)

Value:

> 90

Sampling time:

25 d

Remarks on result:

other: 10-day window reached

Results with reference substance:

86.95 % degradation after 14 days and 98.19% after 29 days.

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Conclusions:

Based on the results of the CO2 evolution test, maleic acid is considered readily biodegradable.

Executive summary:

The biodegradation of maleic acid was studied in the CO₂ evolution test according to the OECD test guideline 301 B with activated sludge from a domestic sewage treatment plant. Maleic acid was applied with 33.3 mg/L. The experiment was conducted in compliance with the OECD GLP standards.

The cumulative CO₂ production in the reaction vessels was measured over the complete experimental phase of 28 days. Maleic acid was biodegraded by 13.24 %, 68.15 %, 75.33 %, and 97.08 % after 2, 10, 14, and 28 days, respectively.

Substances are considered to be readily biodegradable in this test if CO₂ production is equal to or greater than 60 % of the theoretical value. This value has to be reached in a 10-d window after reaching 10 % of the CO₂ production and within the test period. Since 97.08 % degradation was achieved during the test period of 28 days, maleic acid is considered to be readily biodegradable.

Reference 2

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

read-across from supporting substance (structural analogue or surrogate)

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

Duration of test (contact time):

d

Parameter:

% degradation (CO2 evolution)

Value:

> 90

Sampling time:

25 d

Remarks on result:

other: 10-day window reached

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Conclusions:

Based on the results of the CO2 evolution test, maleic acid is considered readily biodegradable.

Executive summary:

The biodegradation of maleic acid was studied in the CO₂ evolution test according to the OECD test guideline 301 B with activated sludge from a domestic sewage treatment plant. Maleic acid was applied with 33.3 mg/L. The experiment was conducted in compliance with the OECD GLP standards.

The cumulative CO₂ production in the reaction vessels was measured over the complete experimental phase of 28 days. Maleic acid was biodegraded by 13.24 %, 68.15 %, 75.33 %, and 97.08 % after 2, 10, 14, and 28 days, respectively.

Substances are considered to be readily biodegradable in this test if CO₂ production is equal to or greater than 60 % of the theoretical value. This value has to be reached in a 10-d window after reaching 10 % of the CO₂ production and within the test period. Since 97.08 % degradation was achieved during the test period of 28 days, maleic acid is considered to be readily biodegradable.

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.

Reference 3

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

no data

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

Only limited information on test performance available.

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 E (Ready biodegradability: Modified OECD Screening Test)

GLP compliance:

no

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Duration of test (contact time):

21 d

Parameter followed for biodegradation estimation:

DOC removal

Details on study design:

TEST SYSTEM
- Number of culture flasks/concentration: 2

CONTROL AND BLANK SYSTEM
- Inoculum blank: yes

Parameter:

% degradation (DOC removal)

Value:

93

Sampling time:

21 d

Details on results:

Degradation % after:
7d: 86/83
14d: 76/68

Validity criteria fulfilled:

not specified

Interpretation of results:

readily biodegradable

Conclusions:

Maleic acid is readily biodegradable.

Executive summary:

The biodegradation of maleic acid was studied in the Modified OECD Screening Test according to OECD Guideline 301 E with activated sludge from a domestic sewage treatment plant. The substance was incubated for 21 days, biodegradation was followed by DOC removal.

After 21 days, the substance was degraded by 93 %. In conclusion maleic acid is considered to be readily biodegradable.

Reference 4

Endpoint:

biodegradation in water: ready biodegradability

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

Parameter:

% degradation (DOC removal)

Value:

93

Sampling time:

21 d

Details on results:

Degradation % after:
7d: 86/83
14d: 76/68

Validity criteria fulfilled:

not specified

Interpretation of results:

readily biodegradable

Conclusions:

Maleic acid is readily biodegradable.

Executive summary:

The biodegradation of maleic acid was studied in the Modified OECD Screening Test according to OECD Guideline 301 E with activated sludge from a domestic sewage treatment plant. The substance was incubated for 21 days, biodegradation was followed by DOC removal.

After 21 days, the substance was degraded by 93 %. In conclusion maleic acid is considered to be readily biodegradable.

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.

Reference 5

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

no data

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 301 C (Ready Biodegradability: Modified MITI Test (I))

GLP compliance:

no

Oxygen conditions:

aerobic

Inoculum or test system:

mixture of sewage, soil and natural water

Details on inoculum:

- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure): In March, June, September, and December, sludge was sampled at the following 10 places in Japan: 1. Fukogawa city sewage plant, 2. Fukashiba industry sewage plant, 3. Nakahama city sewage plant, 4. Ochiai city sewage plant, 5. Kitakami river, 6. Shinano river, 7. Yoshino river, 8. Lake Biwa, 9. Hiroshima bay, 10. Dookai bay; sampling: 1. City sewage: Returned sludge from sewage plants was taken. 2. Rivers, lake and sea: Surface water and surface soil which were in contact with atmosphere were collected.
- Method of cultivation: About 30 minutes after ceasing aeration to the sludge mixture, supernatant corresponding to about 1/3 of the whole volume was removed. Then the equal volume of dechlorinated water was added to the remaining portion and aerated again, followed by addition of synthetic sewage at a concentration of 0.1% (w/v). This procedure was repeated once every day. The culturing was carried out at 25 ± 2 °C. 5 L of the filtrate of the supernatant of old activated sludge was mixed with 500 mL of the filtrate of the supernatant of new sludge and cultured at pH 7.0 ± 1.0 under sufficient aeration using prefiltered open air. During the cultivation, appearance of the supernatant, precipitability, formation of flock, pH, dissolved oxygen concentration in the solution and temperature were checked and necessary adjustments were made, Microflora in the activated sludge was microscopically observed and sludge with no abnormal symptom was used for the test.
- Concentration of inoculum: 30 mg/L

Duration of test (contact time):

14 d

Initial conc.:

100 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

TEST CONDITIONS
- Composition of medium: 3 mL each of four stock solutions, as described in JIS K 0102-1986-21, are diluted to 1000 mL with purified water
- pH: 7.0
- pH adjusted: yes
- Suspended solids concentration: determined according to Method Japanese Industrial Standards (JIS) K 0102-1986-14.1

TEST SYSTEM
- Culturing apparatus: Closed system oxygen consumption measuring apparatus (Coulometer: Ohkura Electric Co., Ltd.); 300 mL vessel, absorbent for evolving carbon dioxide Soda lime No .l (extra pure reagent, Wako Pure Chemical Industries, Ltd.).
- Number of culture flasks/concentration: 1
- Measuring equipment: Coulometer, Okhura Electric Co., Ltd.
- Test performed in open system: no
- Details of trap for CO2 and volatile organics if used: soda lime, extra pure, Wako Pure Chemical Industries, Ltd.)

CONTROL AND BLANK SYSTEM
- Inoculum blank: yes
- Abiotic sterile control: yes
- Toxicity control: no

Reference substance:

aniline

Parameter:

% degradation (O2 consumption)

Value:

55

Sampling time:

14 d

Validity criteria fulfilled:

not specified

Interpretation of results:

readily biodegradable

Conclusions:

Maleic anhydride was degraded by 55 % after 14 days of incubation; the substance is presumably readily biodegradable.

Executive summary:

The biodegradation of maleic anhydrides was studied in the Modified MITI Test (I) according to OECD Guideline 301 C with inoculum from a mixture of sewage, soil and natural water. Biodegradation of the test item was followed for 14 days by measurement of oxygen consumption.

After 14 days, the substance was degraded by 55 %. In conclusion maleic anhydride is presumably readily biodegradable.

Reference 6

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

2001

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study without detailed documentation

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)

Principles of method if other than guideline:

Maleic anhydride hydrolyzes under test conditions. As a result, maleic acid and its salts are believed to be the test materials investigated in this study.

GLP compliance:

yes

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, non-adapted

Details on inoculum:

Innoculum source: Wareham (Massachusetts, USA) Wastewater Treatment Plant
Innoculum type, concentration: Activated sludge, diluted to 30 mg suspended solids/mL

Duration of test (contact time):

28 d

Initial conc.:

10 mg/L

Based on:

other: C

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

No pre-adaptation phase

Reference substance:

benzoic acid, sodium salt

Test performance:

Protocol deviations:
Temperature was found to reach 31ºC on day 8, but excursion was believed to have lasted only a few hours.
The pH ranged from 7.32 to 7.61 on day 0 and pH 7.54 to 7.60 on Day 28 in test medium.

Parameter:

% degradation (CO2 evolution)

Value:

7.6

Sampling time:

2 d

Parameter:

% degradation (CO2 evolution)

Value:

61.6

Sampling time:

4 d

Parameter:

% degradation (CO2 evolution)

Value:

87.4

Sampling time:

8 d

Parameter:

% degradation (CO2 evolution)

Value:

93.2

Sampling time:

11 d

Parameter:

% degradation (CO2 evolution)

Value:

78.9

Sampling time:

29 d

Remarks on result:

other: test termination

Details on results:

Control/reference substance: 87.1 % at 29 days (test termination)
Achieved a “10-day window"
Lag time: 2 days
No inhibition observed

Maleic anhydride is classified as readily biodegradable, based on the results of the Modified Sturm protocol test. Over 87 % biodegradation was achieved by day 8, using non-adapted activated sludge from a public wastewater treatment plant. Biodegradation of the reference material (sodium benzoate) was about 76 % on day 8. Initial carbon loadings were 10g carbon/L and test temperature was 19-22 ºC.  Given the rapid hydrolysis of maleic anhydride to maleic acid in aqueous systems, these results most likely reflect biodegradation of maleic acid.  

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Conclusions:

Maleic anhydride is readily biodegradable (93% in 11 days).

Executive summary:

The biodegradation of maleic anhydride was studied in a study conducted according to OECD Guideline 301 B (CO₂ evolution test) with non-adapted sewage sludge. Biodegradation of the test item was followed for 28 days. Initial carbon loadings were 10g carbon/L and test temperature was 19-22 °C.  

The 10% threshold was reached between days 2 and 4, with over 80% biodegradation achieved by day 8. The maximum degradation was observed as 93% on day 11. Biodegradation of the reference material (sodium benzoate) was about 76 % on day 8.

In conclusion, maleic anhydride is readily biodegradable.

Reference 7

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

no data

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

Only limited information on test performance available but with sufficient data for scientific evaluation.

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 E (Ready biodegradability: Modified OECD Screening Test)

GLP compliance:

no

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Duration of test (contact time):

28 d

Parameter followed for biodegradation estimation:

DOC removal

Details on study design:

TEST SYSTEM
- Number of culture flasks/concentration: 2

CONTROL AND BLANK SYSTEM
- Inoculum blank: yes

Parameter:

% degradation (DOC removal)

Value:

>= 73 - <= 81

Sampling time:

28 d

Details on results:

Degradation % after:
7d: 8/49
14d: 69/64
21d: 23/67
28d: 73/81

Validity criteria fulfilled:

not specified

Interpretation of results:

readily biodegradable

Conclusions:

Maleic anhydride is readily biodegradable.

Executive summary:

The biodegradation of maleic anhydride was studied in the Modified OECD Screening Test according to OECD Guideline 301 E with activated sludge from a domestic sewage treatment plant. The substance was incubated for 28 days, biodegradation was followed by DOC removal.

After 28 days, the substance was degraded between 73 and 81 %; the 10-day window was met. In conclusion maleic anhydride is considered to be readily biodegradable.

Description of key information

Maleic anhydride is considered to be readily biodegradable according to OECD criteria.

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable

Type of water:

freshwater

Additional information

Several studies investigating the biodegradability of maleic anhydride are available. Since maleic anhydride rapidly hydrolyses in contact with water (DT50 = 0.3 min, Bunton et al., 1963), the study results most likely refer to maleic acid as the product of hydrolysis.

The biodegradability of maleic anhydride was tested in a study following OECD guideline 301 B using domestic activated sludge as inoculum. After 25 days of incubation a degradation rate > 90 % was determined (Bopanna, 2010). Thus, the substance is considered as readily biodegradable according to OECD criteria.

This result is supported by another study according to OECD guideline 301B, reporting 93 % biodegradation in 11 days (OECD SIDS, Maleic Anhydride and Maleic Acid, 2004).

The conclusion is also supported by a study conducted in compliance with OECD guideline 301 E investigating the biodegradability of maleic anhydride and maleic acid separately. Maleic anhydride was degraded by 70–80 % after 28 days, whereas a degradation rate of 93 % was detected for maleic acid after 21 days (Trenel and Kuehn, 1982).  

Comparable results were determined in a study testing the biodegradability of maleic anhydride in compliance with OECD guideline 301 C. A biodegradation rate of 55 % was detected after 14 days of incubation (MITI, 1992).