reaction mass of 5-chloro-2-methyl-4-isothiazolin-3-one and 2-methyl-2H -isothiazol-3-one

Other distribution data

Administrative data

Endpoint:

other distribution data

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1996

Report date:

1996

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: U.S. Environmental Protection Agency, 40 CFR § 158, Subdivision N, Chemistry, Environmental Fate 163-1

Deviations:

no

GLP compliance:

no

Type of study:

soil leaching

Media:

water - soil

Test material

Test material information

Constituent 1

Test material form:

not specified

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: Rohm and Haas, Batch No. 555.0104h2

RADIOLABELLING INFORMATION (if applicable)
- Radiochemical purity: 96.58%
- Specific activity: 38.4 mCi/g
- Locations of the label: 14C label was at the 4 and 5 position

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Not reported
- Stability under test conditions: The half life of CMIT was determined previously in a sandy loam soil to be 5.5 hours
- Solubility and stability of the test substance in the solvent/vehicle: Water solubility (deionized water) > 1000 ppm
- Reactivity of the test substance with the solvent/vehicle of the cell culture medium: No

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing: Approximately 370 μCi (~9.6 mg) of 14C CMIT was dissolved in 3.5 mL of ethanol
- Final dilution of a dissolved solid, stock liquid or gel: The solution was radioassayed and found to contain 233, 180 dpm per microliter (2.74 μg/μL)

FORM AS APPLIED IN THE TEST (if different from that of starting material)
Liquid

Applicant's summary and conclusion

Conclusions:

The study provided satisfactorily describes the mobility for CMIT and its soil metabolites per U.S. Environmental Protection Agency, 40 CFR § 158, Subdivision N, Chemistry, Environmental Fate 163-1. Parent and its metabolites had intermediate mobility as over 50% of the applied activity was not mobile. Since the adsorption coefficient indicates that parent is mobile, the lack of parent’s detection in the leachate is probably the result of continued degradation while passing through the column. It is highly likely that with continuing time parent degrades to metabolites which subsequently form a tight association with the post extraction solids becoming bound and of very limited mobility.

Executive summary:

The test guideline followed were U.S. Environmental Protection Agency, 40 CFR § 158, Subdivision N, Chemistry, Environmental Fate 163-1. There were four minor GLP deviations; 1) soil was not analyzed under GLP protocols but employed proper scientific practices, 2) some of the chromatographic standards were not analyzed by GLP protocols, 3) some automated data collection was dated by the computer rather than by personnel, and 4) some aliquot values taken for LSC were first recorded on LSC vial caps and then transcribed to LSC printouts. None of these deviations had a detrimental impact on the study.

Initially, 100 g of Pasquotant sandy loam was added to biometer flasks and dosed with 1 ppm¹⁴C CMIT. Volatiles were trapped using KOH in the side arm. After 5 hours (~ one half-life) the soil from 6 of the biometer flasks were combined, mixed into a single sample, and radioassayed.

Leaching columns were prepared by placing air dried and sieved sand, sandy loam, silt loam or clay loam soil into duplicate glass columns prepared from 6 cm tall glass rings. The final packed column length was 30 cm. The soils were wetted with 0.01M CaCl₂(from the bottom up) and after removing the excess of water removed. To the top of each 30 cm soil column, 50 g of the aged¹⁴C CMIT treated sandy loam soil was added. The equivalent of 50 cm of rain (on a cross sectional area bases; 529 mL of 0.01M CaCl₂) was added to each column, the leachate collected, and radioassayed. At the conclusion, the 6 cm rings were separated , the soil removed, and radioassayed. 

Approximately 55%-64% of the applied activity was not mobile and remained in the treated soil segment. In the sandy loam, clay loam and silt loam soils, the 6 cm segment immediately below the treated soil contained about 10-12% of the applied activity. Lower segments had successively decreasing percentages of radioactivity. In the sand, the decrease was not pronounced as the segment immediately below the treated soil had 1.96% of the applied and the bottom segment, 1.49%. The amount of applied activity in the leachate ranged from 15.17% (Lansdale silt loam) to 35.55% (Lakeland sand). In the treated segment of soil placed on top of the column, parent comprised about 25% of the applied activity, metabolites about 10%, volatiles about 5% and bound residues about 50%. In the 6 cm segment immediately below the treated segment, over 93% of the activity was in the post extraction solids and is considered to be bound residue.

No parent was detectable in the leachate. The metabolites were polar and primarily acidic in nature. The major ones cochromatographed with standards of malonamic acid, malonic acid, N-methyl malonamic acid, and N-methyl oxamic acid.