N-ethyl-o(or p)-toluenesulphonamide

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Endpoint:

biodegradation in water: screening test, other

Remarks:

Inherent test: shake flask carbon dioxide evolution test ASTM E35.24 (2/80)

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

1983

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

test procedure in accordance with national standard methods with acceptable restrictions

Remarks:

study performed according to guideline and reviewed for compliance with GLP, however relevant and detailed information is lacking in the report, but a reference of where the info can be retrieved is given.

Qualifier:

according to guideline

Guideline:

other: American Society for Testing Materials, Proposed Standard Practice for the Determination of the Ultimate Biodegradability of Organic Chemicals, Draft No. 3, ASTM E35.24 Subcommittee, Aquatic Biotransformati on Task Group, 2/80

Version / remarks:

Identical to that described in ASTM Draft No.3 for the Proposed Standard Practice for the Determination of the Ultimate Biodegradability of Organic Chemicals

GLP compliance:

yes

Remarks:

page 5 of the report indicates review for compliance with GLP

Specific details on test material used for the study:

Santicizer 8 (log #1916320), mixture of N-ethyl-o-toluene sulfonamide and N-ethyl -p-toluene sulfonamide, H3C-C6H4-S02NHC2H5, QH-18 , %C = 54.55

Oxygen conditions:

aerobic

Inoculum or test system:

mixture of sewage, soil and natural water

Remarks:

mixture of soil, raw sewage and activated sludge mixed liquor.

Details on inoculum:

mixture of soil, raw sewage and activated sludge mixed liquor

Duration of test (contact time):

35 d

Initial conc.:

25.4 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

an acclimated inoculum is prepared by the stepwise addition of test compound to a defined medium over a 14-day period. This medium is derived·from soil , raw sewage, and activated sludge mixed l i quor. At the conclusi on of the acclimati on period, 100 ml of inoculum are mixed with 900 ml of minimal salts media in a fluted 2-liter Erl enmeyer flask. After aerati ng the mi xture with 70% oxygen in ni trogen, a known quantity of the test compound is added to each flask. An open reservoi r contai ning 10 ml of 0.15N bari um hydroxi de is suspended via a glass tube inserted in a neoprene stopper . Provisions for removal and addition of the bari um hydroxide and for sampling the aqueous media are provided. After sealing, the flasks are agitated on a rotary shaker in the dark at ambient temperature. Periodic removal , e.g., (3, 7, 1 4, 21 , 28, and 35 days) and titration of the barium hydroxide solution are used to determine the C02 evolved. Fresh bari um hydroxide is added back at each sampling point. C02 evol ution values obtained with the control are subtracted from values for the test compound.

Quadruplicate flasks for controls and each plasticizer product were employed. A positive control, sodium citrate, in triplicate flasks was used to monitor biological activity.

Reference substance:

other: sodium citrate

Test performance:

The carbon dioxide evolution for the positive control fell in the expected 70-95 percent range.

Key result

Parameter:

% degradation (CO2 evolution)

Value:

3

St. dev.:

3

Sampling time:

35 d

Results with reference substance:

The carbon dioxide evolution for the positive control fell in the expected 70-95 percent range.

Validity criteria fulfilled:

not specified

Remarks:

the positive control result was valid

Interpretation of results:

under test conditions no biodegradation observed

Conclusions:

Santicizer 8 is slowly biodegraded.

Executive summary:

Ultimate biodegradation screening using the shake flask carbon dioxide evolution test (according to ASTM E35.24, GLP) was carried out for two specialty plasticizer products, Santicizer 8 and Santicizer 9. 14d Acclimated inoculum was exposed to 25 mg/L test substance for 35 days. The degree of conversion to carbon dioxide for both products was not significant ranging from 3 to 13 percent of theory, indicating relatively slow biodegradation or slight alteration of the parent molecules. Results of the refernce substance was in the expected range, indicating proper test procedures.

Description of key information

Ultimate biodegradation screening using the shake flask carbon dioxide evolution test (according to ASTM E35.24, GLP) was carried out for two specialty plasticizer products, Santicizer 8 and Santicizer 9. 14d Acclimated inoculum was exposed to 25 mg/L test substance for 35 days. The degree of conversion to carbon dioxide for both products was not significant ranging from 3 to 13 percent of theory, indicating relatively slow biodegradation or slight alteration of the parent molecules. Results of the refernce substance was in the expected range, indicating proper test procedures.

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed

Type of water:

freshwater