Registration Dossier

Administrative data

Endpoint:
biodegradation in soil
Type of information:
experimental study
Adequacy of study:
other information
Reliability:
3 (not reliable)
Rationale for reliability incl. deficiencies:
other: Study of primary degradation. No information about the test substance.

Data source

Reference
Reference Type:
publication
Title:
Effect of chemical structure on microbial degradation of substitued benzenes
Author:
Alexander M and Lustigman BK
Year:
1966
Bibliographic source:
J. Agr. Food Chem., 14, 410-413

Materials and methods

Test guideline
Qualifier:
no guideline followed
Principles of method if other than guideline:
The rate of degradation of substituted benzenes by soil microorganisms was determined by a spectrophotometric technique (loss of UV absorbancy).
GLP compliance:
no
Test type:
other: primary degradation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
No data
Radiolabelling:
no

Study design

Oxygen conditions:
aerobic
Soil classification:
not specified
Details on soil characteristics:
Soil microorganisms used were from suspension of Niagara silt loam. No more data on the soil characteristics
Duration of test (contact time)
Duration:
64 d
Initial test substance concentration
Initial conc.:
15 other: mg/l
Based on:
test mat.
Parameter followed for biodegradation estimation:
other: Test mat. analysis by loss of UV absorbancy at 289 nm
Details on experimental conditions:
The solution contained the test compound as the sole carbon source to support microbial proliferation and 1.6 g K2HPO4, 0.4 g of KH2PO4, 0.5 g of NH4NO3, 0.2 g of MgSO4,7H2O, 25 mg of CaCl2,2H2O, 2.3 mg of FeCl3,6H2O and 1000 ml of distilled water. 40 ml aliquots of the medium were placed in 4-oz. screww cap bottles, 45 mm diameter x 80 mm high and these were inoculated with 1 ml of a 1% suspension of Niagara silt loam. A parallel series of reaction vessels was set up identical to the first except that each bottle also contained 8 mg of HgCl2 and 5.10exp-7 M Tween 80. Readings were made on these flasks at the same time intervals. Another series identical to the first was set up to determine if the chemical at the concentrations employed were toxic to the microflora; these vessels received glucose to a finalconc. of 1% and growth in the tube was recorded visually. The bottles were incubated in the dark at 25°C. At intervals of 3h, 6h, 1, 2, 4, 8, 16, 32 and 64 days after inoculation, the solutions were mixed, an aliquot was removed and the suspension was centrifuged.

Results and discussion

% Degradation
% Degr.:
100
Parameter:
test mat. analysis
Sampling time:
8 d

Applicant's summary and conclusion

Conclusions:
Paradimethoxybenzene was found to be 100% biodegraded by a mixed soil microflora within 8 days, based on loss of UV absorbancy.