Reaction products of dimethyl phosphonate with 2-alkyl-2-alkylpropanediol and alkanediol

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

17 January 2017 to 01 Feberuary 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Report date:

2017

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Deviations:

yes

Remarks:

deviation in body weights for male rats with no impact on results or integrity of the study (see below)

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.3 (Acute Toxicity (Dermal))

Deviations:

yes

Remarks:

deviation in body weights for male rats with no impact on results or integrity of the study (see below)

Test guideline 3

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.1200 (Acute Dermal Toxicity)

Deviations:

yes

Remarks:

deviation in body weights for male rats with no impact on results or integrity of the study (see below)

GLP compliance:

yes

Test type:

fixed dose procedure

Limit test:

yes

Test material

Reference

Name:

Unnamed

Type:

Constituent

Test material form:

liquid: viscous

Details on test material:

- Appearance/physical state: Clear viscous liquid
- Storage conditions: Room temperature in the dark

Test animals

Species:

rat

Strain:

Sprague-Dawley

Remarks:

Crl(CD)SD

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST SYSTEM, ANIMAL RECEIPT AND ACCLIMATION
- Crl:CD(SD) rats were used as the test system on this study. This species and strain is generally recognised as appropriate for acute dermal toxicity studies. The Sprague Dawley rat was utilised because it is a widely used strain for which significant historical control data are available. The number of animals selected (5/sex) was the minimum required to satisfy regulatory guidelines demonstrating no mortality at the selected limit dose level. The experimental design uses the general procedures and standards required by the current federal and international test guidelines.
- The albino rats utilised for this study were received in good health from Charles River Laboratories, Inc., Raleigh, NC, on 10 Jan 2017. The rats were inspected by a qualified technician upon receipt and uniquely identified with a subcutaneous microchip (BMDS system) implanted in the dorsoscapular area. The rats were acclimated to laboratory conditions for 8 days. During this period, each animal was observed twice daily for mortality and changes in general appearance or behaviour.

ANIMAL HOUSING
- Upon arrival, all animals were housed individually in clean, stainless steel, wire-mesh cages suspended above cage-board. The animals were maintained by the animal husbandry staff of Charles River in accordance with SOPs. The animal facilities at Charles River Ashland are accredited by AAALAC International.
- Enrichment devices were provided to all animals as appropriate throughout the study for environmental enrichment and to aid in maintaining oral health of the animals, and were sanitised weekly.

DIET, DRINKING WATER AND MAINTENANCE
- The basal diet used in this study, PMI Nutrition International, LLC, Certified Rodent LabDiet 5002, is a certified feed with appropriate analyses performed by the manufacturer and provided to Charles River.
- Municipal water supplying the facility was analysed for contaminants according to Charles River SOPs. The results of the diet and water analyses are maintained at Charles River.
- No contaminants were present in animal feed or water at concentrations sufficient to interfere with the objectives of this study.
- The basal diet and municipal water, delivered by an automatic watering system, were provided ad libitum throughout the acclimation period and during the study.

ENVIRONMENTAL CONDITIONS
- All animals were housed throughout the acclimation period and during the study in an environmentally controlled room. The room temperature and humidity controls were set to maintain environmental conditions of 68 °F to 78 °F (20 °C to 26 °C) and 30 % to 70 %,
respectively.
- Room temperature and relative humidity data were monitored continuously and were scheduled for automatic collection on an hourly basis.
- Actual mean daily temperature ranged from 72.4 °F to 72.5 °F (22.4 °C to 22.5 °C) and mean daily relative humidity ranged from 40.4 % to 50.9 % during the study.
- Fluorescent lighting provided illumination for a 12-hour light (0600 hours to 1800 hours)/12-hour dark photoperiod. Lighting conditions were recorded every 15 minutes. The 12-hour light/12-hour
dark photoperiod was interrupted as necessary to allow for the performance of protocol-specified
activities.
- Air handling units were set to provide a minimum of 10 fresh air changes per hour.

ASSIGNMENT OF ANIMALS TO TREATMENT GROUPS
- Animals used in the study were randomly selected based on health and body weight from available stock and assigned to groups by use of WTDMS.
- Individual body weights at randomisation were within  20 % of the mean for each sex.
- The selected animals were approximately 8 weeks old at initiation of dosing; body weight values ranged from 244 g to 285 g for males and from 178 g to 204 g for females.

Administration / exposure

Type of coverage:

semiocclusive

Vehicle:

unchanged (no vehicle)

Details on dermal exposure:

PREPARATION
- Prior to use, the bulk test substance was transferred into a storage container for dispensation.

TEST SUBSTANCE ADMINISTRATION
- The test substance was dosed undiluted based on its density. The dose volume was determined by dividing the dose level of 2000 mg/kg, by the density (1.1093 g/mL, as determined by Charles River Formulations Department personnel). Individual doses were calculated based on body weights taken just prior to dosing and the dose volume of 1.803 mL/kg.
- On the day prior to dosing, the hair was removed from the backs and flanks of the rats using an electric clipper. Individual doses of the test substance were applied to the maximum area possible on the dorsal skin. Doses covered at least 10 % of the total body surface.
- Each dose was applied to the unabraded skin under a 4-ply gauze pad that were secured with non-irritating tape.
- Upon completion of exposure, the bandages were removed and the sites were wiped with disposable paper towels moistened with tepid tap water.

Duration of exposure:

24 hours

Doses:

2000 mg/kg bw

No. of animals per sex per dose:

Five males and five females

Control animals:

no

Details on study design:

MORTALITY
- The rats were observed twice daily, once in the morning and once in the afternoon, for mortality
and moribundity.

CLINICAL OBSERVATIONS
- The rats were observed at the time of dosing and at approximately 1, 2, and 4 hours post application on Study Day 0 and once daily thereafter for 14 days.
- Observations included, but were not limited to, evaluation for changes in appearance of skin and fur, eyes, mucous membranes, respiratory and circulatory systems, autonomic effects, and central nervous system effects.

DERMAL OBSERVATIONS
- The application sites were examined for erythema, edema, and other dermal findings (see Appendix 3, attached) beginning 30–60 minutes after bandage removal and daily thereafter through Study Day 14.
- The areas of application were clipped free of hair on the day prior to dosing and as needed to facilitate accurate dermal observations.

BODY WEIGHTS
- Body weights were obtained and recorded on Study Days 0 (initiation), 7, and 14 (termination).

NECROPSY
- Upon termination, all rats were euthanized by carbon dioxide inhalation. The major organ systems of the cranial, thoracic, and abdominal cavities were examined for all animals.
- Tissues were not collected.

DATA ACQUISITION AND ANALYSIS
- The major computer systems used on this study include, but are not limited to, those listed in the attached table.
- All computerised systems used for data collection during the conduct of this study have been validated (with the exception of Microsoft Office); when a particular system has not satisfied all requirements, appropriate administration and procedural controls were implemented to assure the quality and integrity of the data.

Results and discussion

Effect levels

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

- There were no deaths during the study.

Clinical signs:

- There were no clinical observations noted during the study.

Body weight:

- There were no remarkable body weight changes noted during the study.
- All animals gained weight during the Study Day 0–7 and 7–14 intervals and surpassed their Study Day 0 body weight by Study Day 14.

Gross pathology:

- There were no macroscopic findings at the scheduled necropsy.

Other findings:

DERMAL OBSERVATIONS
- Very slight (grade 1) and/or slight (grade 2) erythema was noted for all males during Study Days 1–2. Very slight (grade 1) erythema and/or edema was noted in all males during Study Days 3–6; desquamation was noted for all males during this interval. Males did not show signs of irritation during Study Days 7–9. During Study Days 10–11, one male (No. 5933) was noted with scabbing within the dose site and two males (Nos. 5927 and 5928) were noted with desquamation. Males did not show signs of irritation during Study Days 12–14.
- Very slight (grade 1) or slight (grade 2) erythema was noted for 4 of 5 females on Study Day 1 and for all females on Study Day 2. Very slight (grade 1) and/or slight (grade 2) erythema and/or edema with desquamation was noted for all females during Study Days 3–6; in addition, two females (Nos. 5940 and 5937) were noted with scabbing within the dose site on Study Day 3. Females did not show signs of irritation during Study Days 7–9. During Study Days 10–11, three females (Nos. 5934, 5940, and 5937) were noted with desquamation and/or scabbing within the dose site. Females did not show signs of irritation during Study Days 12–13. On Study Day 14, one female (No. 5940) was noted with scabbing within the dose site; the remaining four females did not show signs of irritation.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

The LD50 of the test item was greater than 2000 mg/kg when administered once for 24 hours to the clipped, unabraded skin of male and female albino rats.

Executive summary:

GUIDELINE

The key study was performed in accordance with OECD Guidelines for Testing of Chemicals, Section 402 (1987), the OPPTS Guideline 870.1200 (1996), and the EEC Directive 92/69, Annex V, B3 (1992). The objective was to determine the acute dermal median lethal dose, evaluate potential systemic toxicity, and evaluate the local irritative effects of the test substance when applied once to the skin of albino rats.

 

METHODS

The test substance was administered once dermally for a 24-hour period under semi-occlusive dressing to Crl:CD(SD) albino rats for the determination of a median lethal dosage (LD50). The test substance was administered to 1 group of 5 male and 5 female rats at a dose level of 2000 mg/kg. Mortality, clinical observations, dermal findings and body weight changes were evaluated over a 14-day observation period. All animals were subjected to a gross necropsy.

 

There were no deaths, remarkable body weight changes, or test substance-related clinical observations or gross necropsy findings. Dermal findings noted during the study consisted of very slight and/or slight erythema and/or oedema with desquamation noted for all males and females during Study Days 1 to 6; in addition, 2 females were also noted with scabbing within the dose site on Study Day 3. On Study Days 10–11, 3 males and 3 females were noted with desquamation and/or scabbing within the dose site. A single female was noted with scabbing within the dose site on Study Day 14. Dermal findings for the remainder of the animals subsided by Study Day 12.

 

CONCLUSION

The LD50 of the test item was greater than 2000 mg/kg when administered once for 24 hours to the clipped, unabraded skin of male and female albino rats.