6-[methyl(phenylsulphonyl)amino]hexanoic acid

Biodegradation in water: screening tests

Administrative data

Endpoint:

biodegradation in water: inherent biodegradability

Type of information:

experimental study

Adequacy of study:

other information

Study period:

2005-04-12 to 2005-05-10

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study, no deficiencies

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2005

Report date:

2005

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 302 B (Inherent biodegradability: Zahn-Wellens/EMPA Test)

Deviations:

no

GLP compliance:

yes

Remarks:

test was carried out under GLP conditions

Test material

Test material information

Constituent 1

Reference substance name:

Hexanoic acid, 6-[methyl(phenylsulfonyl)amino]- , sodium salt

IUPAC Name:

Hexanoic acid, 6-[methyl(phenylsulfonyl)amino]- , sodium salt

Details on test material:

Based on the pKa of 4,74 for Hexanoic acid, 6-[methyl(phenylsulfonyl)amino]- the acid coexist under environmental conditions (pH 4-9) in aqueous media iwth its salt e.g. Hexanoic acid, 6-[methyl(phenylsulfonyl)amino]- , sodium salt. This means the salt can be used as test material as well as the composition of acid and salt in aqueous media is only detemined by the pKa of the acid. The sodium salt is a clear, light yellow liquid with amber sediment.

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

Activated sludge from the municipal sewage treatment plant Frankfurt-Niederrad, 6g/L

Duration of test (contact time):

28 d

Initial test substance concentration

Initial test substance concentration 1

Initial conc.:

673 mg/L

Based on:

test mat.

Initial test substance concentration 2

Initial conc.:

1 350 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

DOC removal

Details on study design:

Test vessels 4L total volume, test volume 2,5 L.Two vessel for inoculum control (C1, C2), four vessels for the test substance at two different concentrations S1 to S4, one vessel for the reference substance Diethylenglycol R and one vessel for the abiotic control A. Incubation took place at 22 deg C +/- 2 deg in diffuse light. Agitation with stirrer.

Results and discussion

% Degradation

Parameter:

% degradation (DOC removal)

Value:

27 - 31

Sampling time:

28 d

Details on results:

The level of biodegradation of 10% was reached after 3-4 days, the maxiumum level of biodegradation was reached after 28d. The biodegradation observed can be explained by the oxidative degradation of 4 CH2 units of the hexanoic aicd chain (more information see IUCLID Section 5.2.4)

BOD5 / COD results

Results with reference substance:

The reference substance Diethylenglycol was tested on biodegradability at a concentration of 424 mg/L. The 70% pass level for DOC removal according the requirement in the guideline was reached within 14 days.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Remarks:

The validty criteria according the OECD 302B Guideline are fulfilled:1) the reference substance reached the pass level of 70% within 14d, 2) the test subst. shows gradual DOC removal, 3) the DOC elimination of the test substanc after 3h was <20%

Interpretation of results:

not inherently biodegradable

Conclusions:

Primary biodegradation is observed. The metabolite is known (see IUCLID Section 5.2.4). The metabilite degrades very slowly only.