Tetrabromophthalic anhydride

Biodegradation in soil

Administrative data

Endpoint:

biodegradation in soil

Type of information:

experimental study

Adequacy of study:

key study

Study period:

March 27 - August 16, 1979

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: The study is well-reported, and conducted prior to established guidelines with no information on GLPs.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1979

Materials and methods

Principles of method if other than guideline:

Soil was treated with 14C-TBPA. At 0, 1, 2, 4, 7, 14 and 28 d soil was sampled and analyzed. 3 replicates at each dose.

GLP compliance:

not specified

Test type:

laboratory

Test material

Test material information

Constituent 1

Reference substance name:

14C-tetrabromophthalic anhydride

IUPAC Name:

14C-tetrabromophthalic anhydride

Details on test material:

14C-TBPA: uniformly labeled in aromatic ring. Specific activity: 11.6 mCi/mM; radiochemical purity 98%. Synthesized by Midwest Research Institute.

Radiolabelling:

yes

Study design

Oxygen conditions:

aerobic

Soil classification:

USDA (US Department of Agriculture)

Soil properties

Soil no.:

#1

Soil type:

sandy loam

% Clay:

28.4

% Silt:

23.2

% Sand:

48.4

% Org. C:

0.2

pH:

6.3

CEC:

36 meq/100 g soil d.w.

Bulk density (g/cm³):

1.67

Duration of test (contact time)

Soil No.:

#1

Duration:

28 d

Initial test substance concentration

Initial test substance concentration 1

Soil No.:

#1

Initial conc.:

1 mg/kg soil d.w.

Based on:

test mat.

Initial test substance concentration 2

Soil No.:

#1

Initial conc.:

10 mg/kg soil d.w.

Based on:

test mat.

Experimental conditions

Soil No.:

#1

Temp.:

28 degrees C

Humidity:

70%

Results and discussion

Material (mass) balance

Soil No.:

#1

Remarks on result:

other: No statistical difference between the 14C-activity at D 0 and 28.

% Degradation

Soil No.:

#1

Parameter:

other: See text below

Half-life / dissipation time of parent compound

Soil No.:

#1

Remarks on result:

other: See text below.

Transformation products:

yes

Identity of transformation products

No.:

#1

Reference

Reference substance name:

Unnamed

IUPAC name:

Tetrabromophthalic acid

Identifier:

common name

Identity:

Tetrabromophthalic acid

Evaporation of parent compound:

no

Details on results:

Very slight volatilization (0.038% at the 10 ug/g level). Soil-bound 14C-activity increased in both levels between 0 and 28 d (~24 and 32% of applied 14C at 28 d in the 1 and 10 ug/g doses, respectively). Due to the high amount bound, soil further extracted with NaOH. All of bound 14C-activity soluble in NaOH at both doses at d 0 and 28. At the 10 ug/g level, the 28 d sample contained 94% TBPA-acid and 4% TBPA. Concluded TBPA-acid binds to soil particles.

TLC resulted indicated no evidence of biodegradation. 95% of 14C-activity identified as TBPA-acid at both d 0 and 28. 1% identified as TBPA, and 4% unknown. In summary, there was no difference in the 0 and 28 d samples, indicating little or no biodegradation of TBPA over the 28 d. However, hydrolysis of TBPA to TBPA-acid was observed.

Applicant's summary and conclusion

Conclusions:

TBPA rapidly hydrolyzed to TBPA-acid. Little volatilization was observed, and a large proportion (24 -32%) of the 14C-activity became soil-bound after 28 days. The soil-bound radiocarbon was identified as TBPA acid (94.0%) and TBPA (4.0%). Biodegradation was not observed. Hydrolysis to TBPA-acid was observed.

Executive summary:

When introduced to soil, TBPA rapidly hydrolyzed to TBPA-acid. Little volatilization was observed, and a large proportion (24 -32%) of the 14C-activity became soil-bound after 28 days. The soil-bound radiocarbon was identified as TBPA acid (94.0%) and TBPA (4.0%). Biodegradation was not observed. Hydrolysis to TBPA-acid was observed.