mancozeb (ISO); manganese ethylenebis(dithiocarbamate) (polymeric) complex with zinc salt  

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1995

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)

Version / remarks:

Annex of Directive 92/69/EEC Part C4-C

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

The source of test organisms is activated sludge freshly obtained from the aeration tank of the waste water treatment plant treating predominantly domestic sewage. On arrival at the laboratory, the mixed liquor is aerated for 4 hours. Then, 3 000 mL of the mixed liquor is homogenised and allowed to settle for 30 minutes. The clear supernatant is decanted to provide sufficient volume for a 1 % inoculum in each carboy.

Duration of test (contact time):

36 d

Initial conc.:

10 mg/L

Parameter followed for biodegradation estimation:

CO2 evolution

Parameter followed for biodegradation estimation:

TOC removal

Parameter followed for biodegradation estimation:

DOC removal

Details on study design:

The test systems were 5-L brown glass bottles connected to absorber bottles containing activated sewage sludge as the inoculum in high quality water and nutrient solution. They were purged with CO2-free air. Sancozeb 800 WP (mancozeb 800 g/kg) and additional water were added to two bottles to give a final concentration of 9.16 mg C/L in 3 L of mixture. A reference substance (aniline) and water were added to a third bottle to give a final concentration of 10 mg C/L. Two other bottles were made to volume with water as controls. The mixtures were continually stirred and CO2-free air bubbled through the mixture for 36 days. Exit air was passed through the absorber bottles, three per system, containing 100 mL of 0.0125M Ba(OH)2. The absorber bottle next to the test bottle was periodically removed for titration with 0.05M HCl and a new absorber bottle added furthest away from the test bottle. On the last day of the test the pH of the test mixture was measured and 1 mL of concentrated HCl added to drive inorganic carbonate. The vessels were aerated overnight and samples removed for dissolved organic carbon (DOC) analysis.

Reference substance:

aniline

Test performance:

Due to the physical nature of the test product, % DOC removal could not be measured. There was 96% DOC removal from the aniline reference and 94% biodegradation (% of theoretical CO2). The biodegradation of Sancozeb 800 WP was 5 and 6% in the two test vessels. An intense smell of H2S came free during the titration of the absorber solutions of the Sancozeb 800 WP test system.

Key result

Parameter:

% degradation (CO2 evolution)

Value:

>= 5 - <= 6

Sampling time:

36 d

Details on results:

Biodegradation (% of ThCO2): 5% and 6% for both samples

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

The biodegradability test with Sancozeb 800 WP using activated sewage sludge as the inoculum resulted in 5 – 6% biodegradation in 36 days. Therefore, Sancozeb 800 WP is not readily biodegradable.

Executive summary:

The biodegradation of Mancozeb was tested in a study with a CO2 evalution test accorinding to OECD 301B.

The test systems were 5-L brown glass bottles connected to absorber bottles containing activated sewage sludge as the inoculum in high quality water and nutrient solution. They were purged with CO₂-free air. Sancozeb 800 WP (mancozeb 800 g/kg) and additional water were added to two bottles to give a final concentration of 9.16 mg C/L in 3L of mixture. A reference substance (aniline) and water were added to a third bottle to give a final concentration of 10 mg C/L. Two other bottles were made to volume with water as controls. The mixtures were continually stirred and CO₂-free air bubbled through the mixture for 36 days. Exit air was passed through the absorber bottles, three per system, containing 100 mL of 0.0125M Ba(OH)₂. The absorber bottle next to the test bottle was periodically removed for titration with 0.05M HCl and a new absorber bottle added furthest away from the test bottle. On the last day of the test the pH of the test mixture was measured and 1 mL of concentrated HCl added to drive inorganic carbonate. The vessels were aerated overnight and samples removed for dissolved organic carbon (DOC) analysis.

Due to the physical nature of the test product, % DOC removal could not be measured. There was 96% DOC removal from the aniline reference and 94% biodegradation (% of theoretical CO₂). The biodegradation of Sancozeb 800 WP was 5 and 6% in the two test vessels. An intense smell of H2S came free during the titration of the absorber solutions of the Sancozeb 800 WP test system.

The biodegradability test with Sancozeb 800 WP using activated sewage sludge as the inoculum resulted in 5 – 6% biodegradation in 36 days. Therefore, Sancozeb 800 WP is not readily biodegradable.

Description of key information

The biodegradability test with Sancozeb 800 WP using activated sewage sludge as the inoculum resulted in 5 – 6% biodegradation in 36 days. Therefore, Sancozeb 800 WP is not readily biodegradable.

Key value for chemical safety assessment

Biodegradation in water:

not biodegradable

Type of water:

freshwater

Additional information

The biodegradation of Mancozeb was tested in a study with a CO2 evalution test accorinding to OECD 301B.

The test systems were 5-L brown glass bottles connected to absorber bottles containing activated sewage sludge as the inoculum in high quality water and nutrient solution. They were purged with CO₂-free air. Sancozeb 800 WP (mancozeb 800 g/kg) and additional water were added to two bottles to give a final concentration of 9.16 mg C/L in 3L of mixture. A reference substance (aniline) and water were added to a third bottle to give a final concentration of 10 mg C/L. Two other bottles were made to volume with water as controls. The mixtures were continually stirred and CO₂-free air bubbled through the mixture for 36 days. Exit air was passed through the absorber bottles, three per system, containing 100 mL of 0.0125M Ba(OH)₂. The absorber bottle next to the test bottle was periodically removed for titration with 0.05M HCl and a new absorber bottle added furthest away from the test bottle. On the last day of the test the pH of the test mixture was measured and 1 mL of concentrated HCl added to drive inorganic carbonate. The vessels were aerated overnight and samples removed for dissolved organic carbon (DOC) analysis.

Due to the physical nature of the test product, % DOC removal could not be measured. There was 96% DOC removal from the aniline reference and 94% biodegradation (% of theoretical CO₂). The biodegradation of Sancozeb 800 WP was 5 and 6% in the two test vessels. An intense smell of H2S came free during the titration of the absorber solutions of the Sancozeb 800 WP test system.

The biodegradability test with Sancozeb 800 WP using activated sewage sludge as the inoculum resulted in 5 – 6% biodegradation in 36 days. Therefore, Sancozeb 800 WP is not readily biodegradable.