Diphosphoric acid, zinc salt, compd. with 1,3,5-triazine-2,4,6-triamine (1:1:2)

Biodegradation in water: screening tests

Administrative data

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:

other: Study conducted to OECD guidelines and GLP

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2011

Report date:

2011

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 (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Reaction products of 1,3,5-triazine-2,4,6-triamine and zinc bis(dihydrogen phosphate)

EC Number:

690-512-6

Cas Number:

1271172-98-5

Molecular formula:

Zn(C3H7N6)2(P2O7)

IUPAC Name:

Reaction products of 1,3,5-triazine-2,4,6-triamine and zinc bis(dihydrogen phosphate)

Test material form:

solid: particulate/powder

Remarks:

migrated information: powder

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, non-adapted

Details on inoculum:

- Activated sludge taken from a sewage treatment plant treating predominately domestic waste.
- Source: The sludge was taken from the activation basin of the ESN (Stadtentsorgung Neustadt)sewage treatment plant, Im Altenschemel , NW-Lachen Speyerdorf.
- The sludge was filtered washed with tap water twice, then washed and re-suspended in test medium. It was then aerated for > 12 hours. The dry matter was determined with 4540 mg suspended solids/L.

Duration of test (contact time):

ca. 28 d

Initial test substance concentration

Initial conc.:

ca. 137 mg/L

Based on:

DOC

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

See table in 'Any other information on materials and methods incl. tables' for information on the test setup. Additionally to this, two procedural control flasks (containing media only) and two controls (containing media and inoculum) were also included.

The test was aimed to be maintained at 19 - 20.5°C throughout (although measured as slightly lower than this, the validity criteria were met and as such this deviation is considered uncritical). A nominal starting concentration of 20 mg organic carbon/L was applied.

All test vessels were aerated with purified, CO2-scrubbed, moistened air. The scrubbing of carbon dioxide was achieved by bubbling the purified air through a flask containing 1.5 m-NaOH. To control the absence of CO2, the air was then led through a flask containing a solution of Ba(OH)2 before reaching the test vessels. Magnetic stirrers were used to prevent deposition of inoculum. The emitting CO2 was trapped 0.25-m-NaOH. Two scrubbers containing 100 mL each were connected in series to the test vessels.

Reference substance

Reference substance:

aniline

Results and discussion

Test performance:

From the biodegradation based on DOC (< 1%), it can be concluded that the test substance is not readily biodegradable.

% Degradation

Parameter:

% degradation (CO2 evolution)

Value:

< 1

Sampling time:

28 d

BOD5 / COD results

Results with reference substance:

The positive control vessels (vessels containing the reference substance aniline) were greater than 60% by the end of the test (mean value of 84% by the end of the test). As such, the activity of the sludge was shown to be satisfactory.

Degradation in the toxicity flask was >25% by Day 14 and 34.6% by the end of the test indicating test validity.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

under test conditions no biodegradation observed

Conclusions:

It is concluded that the test substance was not readily biodegradable under the conditions of the test.