p-toluidine

Biodegradation in water: screening tests

Administrative data

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Guideline study with acceptable restrictions

Data source

Reference

Reference 1

Reference Type:

publication

Title:

Bewertung wassergefaehrdender Stoffe im Hinblick auf Lagerung, Umschlag und Transport und Untersuchung zur Abklaerung substanz- und bewertungsmethodenspezifischer Grenzfaelle bei der Bewertung wassergefaehrdender Stoffe.

Author:

Trenel J, Kuehn R

Year:

1982

Bibliographic source:

Umweltforschungsplan des Bundesministers des Innern

Reference 2

Reference Type:

publication

Title:

Unnamed

Year:

2001

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 E (Ready biodegradability: Modified OECD Screening Test)

Principles of method if other than guideline:

Directive 84/449/EEC, C.3; ISO 7824 (1984) (precursor)

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

m-toluidine

EC Number:

203-583-1

EC Name:

m-toluidine

Cas Number:

108-44-1

Molecular formula:

C7H9N

IUPAC Name:

3-methylaniline

Details on test material:

purity not specified

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

other: effluent of predominantly domestic STP

Duration of test (contact time):

28 d

Initial test substance concentration

Initial conc.:

20 mg/L

Based on:

DOC

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

DOC removal

Details on study design:

-replicates per concentration: 2

Reference substance

Reference substance 1

Reference substance:

aniline

Reference substance 2

Reference substance:

other: hydroquinone

Results and discussion

% Degradation

% Degradation 1

Parameter:

% degradation (DOC removal)

Value:

83 - 91

Sampling time:

14 d

% Degradation 2

Parameter:

% degradation (DOC removal)

Value:

91 - 98

Sampling time:

21 d

% Degradation 3

Parameter:

% degradation (DOC removal)

Value:

64 - 84

Sampling time:

28 d

Details on results:

degradation of m-toluidine (first run)
7 d: - 24 %
14 d: 91 %
21 d: 98 %
28 d: 84 %

degradation of m-toluidine (second run)
7 d: - 24 %
14 d: 83 %
21 d: 91 %
28 d: 64 %

negative values mean an increase of the DOC in the test system compared to the control, no explanation is given for these findings

BOD5 / COD results

Results with reference substance:

- degradation of aniline fulfilled the pass level as 86 +/- 10 % (mean value) were degraded after 14 d
- degradation of hydroquinone showed a greater variability, but observed degradation after 14 d reached the pass level

Any other information on results incl. tables

- The report includes results of a multitude of compounds, whereas only the percentage degradation was reported.

-  as only these results were provided, where control samples fulfilled the validity criteria (stated by the authors), results are assumed to reliable

- there is no explanation for the decreasing degradation observed after day 21, nevertheless observed degradation at day 28 exceeds the pass level of 70 % degradation

- 10 d window: no specific information is presented, but as no degradation was observed on day 7 and 91 % and 83 %, respectively were degraded at day 14, the fulfilment of the 10 d window can be assumed

_____________________________________________________________________________________________

A read across between the two isomers, meta- and para-toluidine, with their corresponding environmental classification N; R50 was already accepted by the European commission working group on the classification and labelling of dangerous substances (2001):

 

p-toluidine (612-024-00-4)

Proposal: N; R50

 

ECBI/57/98	D classification proposals for 9 substances
ECBI/57/98 Add. 7	D environmental classification proposals for substances under agenda point 5.3 and 5.4

 

The proposal for re-classification received from D depends on health concerns.Further they propose a separate entry for p-toluidine, which is now in a common entry together with the meta form.In addition p-toluidinium chloride (EC No 208-740-8) and p-toluidine sulphate (1:1) (EC No 208-741-3) would be included in the same entry as p-toluidine. The D proposal supports the current classification for the environment, N; R50.

            

Sasked on which isomer the environment data was based. D informed that for the meta-form EC50 (for Daphnia) = 0.75 mg/l and that this had been cross read to the para-form for the classification agreed in the 21st ATP. Industry said that they would appreciate to provide information themselves for environmental endpoints.However the Group agreed that it was acceptable to classify the p-toluidine and its salts on the basis of the m-toluidine data. 

 

Conclusion:The Group agreed to classify p-toluidine, p-toluidinium chloride and p-toluidine sulphate (1:1)with N; R50 accompanied by the S-phrase 61 for environmental concerns.The classification for health effects was still under discussion, but as soon as agreed the complete classification proposal will be sent to DG ENV for inclusion in a future ATP.

 

p-toluidine (612-024-00-4), p-toluidinium chloride (EC No 208-740-8) and p-toluidine sulphate (1:1) (EC No 208-741-3)

Classification	Toxicity	Degradation	Bioaccumulation	Escape clause
N; R50	Data	Readily degradable based on data	log KOW (calculated) < 3	Not relevant

Applicant's summary and conclusion

Executive summary:

Testing m-toluidine towards ready biodegradability in a modified OECD screening test, 64 % and 84 % of the test item were degraded after 28 d, respectively (Trenel, 1982). Furthermore, the pass level is reached within hte 10 day window. Thus, the substance can be scored as readily biodegradable.

_____________________________________________________________________________________________

A read across between the two isomers, meta- and para-toluidine, with their corresponding environmental classification N; R50 was already accepted by the European commission working group on the classification and labelling of dangerous substances (2001):

 

p-toluidine (612-024-00-4)

Proposal: N; R50

 

ECBI/57/98	D classification proposals for 9 substances
ECBI/57/98 Add. 7	D environmental classification proposals for substances under agenda point 5.3 and 5.4

 

The proposal for re-classification received from D depends on health concerns.Further they propose a separate entry for p-toluidine, which is now in a common entry together with the meta form.In addition p-toluidinium chloride (EC No 208-740-8) and p-toluidine sulphate (1:1) (EC No 208-741-3) would be included in the same entry as p-toluidine. The D proposal supports the current classification for the environment, N; R50.

            

S asked on which isomer the environment data was based. D informed that for the meta-form EC50 (for Daphnia) = 0.75 mg/l and that this had been cross read to the para-form for the classification agreed in the 21st ATP. Industry said that they would appreciate to provide information themselves for environmental endpoints.However the Group agreed that it was acceptable to classify the p-toluidine and its salts on the basis of the m-toluidine data. 

 

Conclusion:The Group agreed to classify p-toluidine, p-toluidinium chloride and p-toluidine sulphate (1:1)with N; R50 accompanied by the S-phrase 61 for environmental concerns.The classification for health effects was still under discussion, but as soon as agreed the complete classification proposal will be sent to DG ENV for inclusion in a future ATP.

 

p-toluidine (612-024-00-4), p-toluidinium chloride (EC No 208-740-8) and p-toluidine sulphate (1:1) (EC No 208-741-3)

Classification	Toxicity	Degradation	Bioaccumulation	Escape clause
N; R50	Data	Readily degradable based on data	log KOW (calculated) < 3	Not relevant