TRACER YELLOW D-100

Biodegradation in water: screening tests

Administrative data

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2012

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: According to OECD guideline 301B and EC test method C.4-C

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2012

Report date:

2012

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.4-C (Determination of the "Ready" Biodegradability - Carbon Dioxide Evolution Test)

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Test material form:

solid: particulate/powder

Remarks:

migrated information: powder

Details on test material:

Orange solid powder

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

sewage, predominantly domestic (adaptation not specified)

Duration of test (contact time):

ca. 28 d

Initial test substance concentration

Initial conc.:

ca. 15 mg/L

Based on:

other: molecular formula

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

CO2 evolution

Reference substance

Reference substance:

acetic acid, sodium salt

Results and discussion

Preliminary study:

D-100 was not readily biodegradable under the conditions of the modified Sturm test presently performed.

Test performance:

1. The positive control substance was biodegraded by at least 60% (69%) within 14 days.
2. The difference of duplicate values for %-degradation of the test substance was always less than 20.
3. The total CO2 release in the blank at the end of the test did not exceed 40 mg/l (66 mg CO2 per 2 litres of medium, corresponding to 33 mg CO2/l).
4. The Inorganic Carbon content (IC) of the test substance (suspension) in the mineral medium at the beginning of the test was less than 5% of the Total Carbon content (TC). Since the test medium was prepared in tap-water purified by reverse osmosis (Milli-RO water (Millipore Corp., Bedford, Mass., USA, carbon levels < 500 ppb)), IC was less than 5% of TC (mainly coming from the test substance, 12 mg TOC/l).
Since all criteria for acceptability of the test were met, this study was considered to be valid.

% Degradation

Parameter:

% degradation (CO2 evolution)

Value:

>= 69

Sampling time:

14 d

Details on results:

The positive control substance was biodegraded by at least 60% (69%) within 14 days.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

under test conditions no biodegradation observed

Conclusions:

D-100 was not readily biodegradable under the conditions of the modified Sturm test presently performed.

Executive summary:

Determination of ‘ready’ biodegradability: carbon dioxide (CO2) evolution test (modified Sturm test) with D-100.

The study procedures described in this report were based on the OECD guideline No. 301 B, 1992. In addition, the procedures were designed to meet the test methods of the Commission Regulation (EC) No. 440/2008 of 30 May 2008, Publication No. L142, Part C.4-C and the ISO International Standard 9439, 1999 and ISO Standard 10634, 1995.

D-100 was an orange powder with a purity of 99.8%. The test substance was tested in duplicate at ~ 15 mg/l, corresponding to 12 mg TOC/l. The organic carbon content was based on the molecular formula. The Theoretical CO2 production (ThCO2) of D-100 was calculated to be 2.84 mg CO2/mg.

The study consisted of six bottles:

- 2 inoculum blanks (no test substance),

- 2 test bottles (D-100),

- 1 positive control (sodium acetate) and

- 1 toxicity control (D-100 plus sodium acetate).

Since D-100 was not sufficiently soluble to allow preparation of an aqueous solution at a concentration of 1 g/l, weighed amounts were added to the 2-litres test bottles containing medium with microbial organisms and mineral components. To this end, 10 ml of Milli-RO water was added to each weighing bottle containing the test substance. After vigorous mixing (vortex) the resulting suspension was added quantitatively to the test medium. The test solutions were continuously stirred during the test, to ensure optimal contact between the test substance and the test organisms. Test duration was 28 days (last CO2-measurement on the 29th day).

The relative biodegradation values calculated from the measurements performed during the test period revealed no significant biodegradation of D-100.

In the toxicity control, D-100 was found not to inhibit microbial activity.

Since all criteria for acceptability of the test were met, this study was considered to be valid.

In conclusion, D-100 was designated as not readily biodegradable.