Pyridinium, 2,6-dihydroxy-4-methyl-1-[3-(methylamino)propyl]-, sulfate (1:1)

Biodegradation in water: screening tests

Administrative data

Endpoint:

biodegradation in water: inherent biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

August 1992

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study without detailed documentation

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1992

Report date:

1992

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 302 C (Inherent Biodegradability: Modified MITI Test (II))

GLP compliance:

no

Remarks:

not necessary

Test material

Test material information

Constituent 1

Reference substance name:

2,6-dihydroxy-4-methyl-1-[3-(methylazaniumyl)propyl]pyridin-1-ium sulfate

EC Number:

931-673-7

Cas Number:

1333469-72-9

Molecular formula:

C10 H18 N2 O6 S1

IUPAC Name:

2,6-dihydroxy-4-methyl-1-[3-(methylazaniumyl)propyl]pyridin-1-ium sulfate

Test material form:

liquid

Study design

Inoculum or test system:

activated sludge, adapted

Details on inoculum:

- Inoculum: A mixed population of activated sewage sludge micro­ organisms.
- Source: Activated sewage was prepared by sampling 10 different sites around the UK in accordance with OECD Guideline No. 302C.
- Preparation: The mixed sludge was fed daily with a 0.1% synthetic sewage and maintained on a constant aeration at 25 ± 2°C.
- Usage rate: Equivalent to 100 mg dry weight/L.
- Agitation: by magnetic stirrers
- Temperature: 25 ± 1ºC.
- Lighting: The test was carried out in darkness.

Duration of test (contact time):

28 d

Initial test substance concentration

Initial test substance concentration 1

Initial conc.:

30 mg/L

Based on:

test mat.

Initial test substance concentration 2

Initial conc.:

100 mg/L

Based on:

other: aniline

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

O2 consumption

Reference substance

Reference substance:

aniline

Results and discussion

% Degradation

Parameter:

% degradation (O2 consumption)

Value:

0

Sampling time:

28 d

BOD5 / COD results

Results with reference substance:

42% biodegradation after 7 days and 70% after 14 days

Any other information on results incl. tables

 

Day	% Biodegradation
	HYMAP	Aniline
1	0	0
2	0	0
3	0	3
4	0	5
5	3	26
6	7	33
7	16	42
8	20	43
9	13	48
10	8	50
11	3	54
12	3	61
13	2	67
14	0	70
15	2	72
16	0	72
17	0	73
18	0	74
19	0	76
20	0	78
21	0	80
22	0	85
23	0	87
24	0	87
25	0	94
26	0	94
27	0	95
28	0	95

 

*All% Biodegradation values have been corrected for blank values.

 

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

A COD value of 0.50 mg O2/mg was obtained for the test material. HYMAP attained 0% degradation after 28 days calculated from oxygen uptake (% of COD).

Executive summary:

HYMAP attained 0% degradation after 28 days calculated from oxygen uptake (% of Th0D) and so, therefore, cannot be considered as inherently biodegradable under the strict terms and conditions of the OECD Guidelines. The percentage degradation values for Days 7, 8 and 9 for the test material are considered to be the result of experimental variation between the controls and test material vessels especially when the very low carbon content of the test material is taken into account.

Aniline attained 42% biodegradation after 7 days and 70% after 14 days thereby confirming the suitability of the inoculum and culture conditions.

Total organic carbon analysis of the test media at Day 0 and Day 28 showed that aniline attained 99% degradation after 28 days and HYMAP attained 32% degradation after 28 days. The percent degradation value obtained by total organic carbon analysis is higher than those calculated from oxygen intake (% of Th0D). This is considered to be due to analytical error and the very low carbon content of the test material.

For the % Biodegradation calculation a Th0D of 0.51 mg O2/mg was used based on the following values for the test material:

Molecular formula: C10H15N202

Molecular weight: 196.25

Purity:20%

A Modified Miti test was carried out due to the test material being toxic to sewage micro-organisms at the concentration required to conduct a Modified Zahn-Wellens test.

A COD value of 0.50 mg O2/mg was obtained for the test material. HYMAP attained 0% degradation after 28 days calculated from oxygen uptake (% of COD).