Sodium N-methyltaurinate

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

read-across from similar mixture/product

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 C (Ready Biodegradability: Modified MITI Test (I))

Version / remarks:

July 17, 1992

GLP compliance:

yes

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge (adaptation not specified)

Details on inoculum:

Concentration of sludge: 30 mg/L

Duration of test (contact time):

28 d

Initial conc.:

100 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

O2 consumption

Remarks:

BOD

Parameter followed for biodegradation estimation:

TOC removal

Reference substance:

aniline

Key result

Parameter:

% degradation (O2 consumption)

Remarks:

BOD (NO2)

Value:

62

Sampling time:

28 d

Parameter:

% degradation (TOC removal)

Value:

82

Sampling time:

28 d

Parameter:

% degradation (test mat. analysis)

Value:

85

Sampling time:

28 d

Remarks on result:

other: HPLC

Reverse condition/open system test, 28 d (test substance: 30 mg/L, activated sludge: 100 mg/L): TOC removal: 100% , Test substance analysis: 100% (HPLC).

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Conclusions:

According to the OECD 301C Guideline study, N-methyltaurine is readily biodegradable, 62 % (BOD, NO2) have been degraded after 28 days.

Executive summary:

According to the OECD 301C Guideline study, 62 % (BOD, NO2) of N-methyltaurine degrades after 28 days. This shows that N-methyltaurine is readily biodegradable.

N-methyltaurinate is the sodium salt of N-Methyltaurine.

Description of key information

According to the calculation by the EPI Suite by using the models BioWin3 and BioWin5, the criteria for readily biodegradable are BioWin3: weeks or faster and BioWin5: probability is >= 0.5. For sodium N-methyltaurinate, the result of BioWin3 is weeks while the result of BioWin5 is < 0.5. Therefore, the substance should be classified as not readily biodegradable.

However, further empirical studies show that the read-across substance N-methyltaurine is readily biodegradable according to an OECD 301C guideline study (62 % BOD after 28 days). N-methyltaurinate is the deprotonated form of N-methyltaurine. Both sodium N-methyltaurinate and N-methyltaurine are highly soluble in water. Therefore, it is expected that both substances can be degraded by comparable mechanisms in aqueous solution. Hence, the data on N-methyltaurine provide a reasonable measure for the biodegradability of sodium N-methyltaurinate. We conclude that sodium N-methyltaurinate is readily biodegradable. This result is also supported by further read-across substances.

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable

Type of water:

freshwater

Additional information

According to the calculation by the EPI Suite by using the models BioWin3 and BioWin5, the criteria for readily biodegradable are BioWin3: weeks or faster and BioWin5: probability is >= 0.5. For sodium N-methyltaurinate, the result of BioWin3 is weeks while the result of BioWin5 is < 0.5. Therefore, the substance should be classified as not readily biodegradable.

The guideline study according to OECD 301C shows that the read-across substance N-methyltaurine is readily biodegradable (62 % BOD after 28 days). This result is supported by the two guideline studies according to OECD 301B, which show that the read-across substances sodium N-methyl oleoyl taurinate and sodium N-methyl cocoyl taurinate, derivatives are readily biodegradable. This is supported by the handbook data of the J-CHECK database on sodium methyl oleoyl taurate. Further data on N-methyltaurine published by Levine et al. describe the substance to be rapidly biodegradable by plant rhizosphere microbes, although the biodegradation rate is not reported. N-methyltaurinate is the deprotonated form of N-methyltaurine. Both sodium N-methyltaurinate and N-methyltaurine are highly soluble in water. Hence, it is expected that both substances can be degraded by comparable mechanisms in aqueous solution.Therefore, the experimental OECD guideline study on N-methyltaurine provides a reasonable measure for the biodegradability of sodium N-methyltaurinate. In conclusion, sodium N-methyltaurinate is readily biodegradable.