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Environmental fate & pathways

Additional information on environmental fate and behaviour

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Administrative data

Endpoint:
additional information on environmental fate and behaviour
Adequacy of study:
supporting study
Study period:
1991
Reliability:
1 (reliable without restriction)

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1991
Report Date:
1991

Materials and methods

Principles of method if other than guideline:
EPA Guideline, Subdivision N, Section 162-4
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent

Results and discussion

Any other information on results incl. tables

Recovery:
Overall recovery decreased from 96.8 % of the applied radioactivity,  initially, to 83.8 % after 30 days.

Mineralization:
After 30 days of incubation, 0.122 % of the applied radioactivity present  in the KOH traps was shown to be 14CO2. 

Parent compound:
Parent compound accounted for 83.8 % of the applied radioactivity at the  study's termination. The level of Piperonyl Butoxide in water amounted to  44 % at day 0 and 53 % at day 1. 32 % was detected after 30 days of  application. The level of Piperonyl Butoxide in the sediment decreased  from 53 % of applied radioactivity, initially, to 52 % after 30 days.

Metabolites:
Altogether 3 possible metabolites could be observed during the TLC  analysis of water and soil extracts. None exceeded 10 % of applied  radioactivity. One degradate, which had a maxima of 7.1 % at day 14, was  qualitatively identified as one component and named Metabolite F  (Origin). A slightly increase of two further metabolites could be  observed, but not identified. They were named Unknown 1 (Intermediate II,  Rf = 0.05) and Unknown 2 (Intermediate I, Rf = 0.1).

Proposed degradation pathway: 
Parent compound > Intermediate I > Intermediate II > Metabolite F > 14CO2  + Non-extractable residues.

Degradation kinetics:
The half-life of Piperonyl Butoxide under aerobic aquatic conditions was  calculated to be 109 days by using first-order kinetics. The kinetic  constant for the degradation was obtained from the linear regression  analysis of the plot of ln percent applied 14C-Piperonyl Butoxide versus  days (y = -0.00638 x + 4.60, r = -0.899).

Microbial viability:
The plate count analysis showed a slightly decrease of the bacterial but  not of the fungal colonies.

t1/2 at pH: 6.8 = 109 day(s) at 25 °C

Applicant's summary and conclusion

Conclusions:
The results indicate that 14C-Piperonyl Butoxide was not significantly degraded in the aerobic aquatic metabolism study. The level of none degradation product exceeded 10 % of the applied radioactivity.