Sodium diisobutyldithiophosphinate

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

02 -16 February 2012

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

Also complies with OECD GLP regulations.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2012

Report date:

2012

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.1200 (Acute Dermal Toxicity)

Deviations:

no

Test guideline 4

Qualifier:

according to guideline

Guideline:

other: Japanese Ministry of Agriculture, Forestry and Fisheries (JMAFF), 12 Nousan, Notification No 8147, November 2000; including the most recent partial revisions.

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

2011-05-19

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Sodium diisobutyldithiophosphinate

EC Number:

236-419-2

EC Name:

Sodium diisobutyldithiophosphinate

Cas Number:

13360-78-6

Molecular formula:

C8H18NaPS2

IUPAC Name:

sodium [bis(2-methylpropyl)(sulfanylidene)-lambda5-phosphanyl]sulfanide

Test material form:

solid: particulate/powder

Specific details on test material used for the study:

- Name of test material (as cited in study report): S-10793
- IUPAC nomenclature - Sodium diisobutyldithiophosphinate
- Lot S-20227-170B
- Appearance - White powder with lumps
- CAS No. 13360-78-6
- Molecular Formula - C8H18PS2.Na
- Molecular Weight - 232 g/mole
- Purity 93-94%
- Expiration date of the lot/batch: 16 December 2013
- Storage condition of test material: At room temperature in the dark

Test animals

Species:

rat

Strain:

Wistar

Remarks:

Crl:WI (Han)

Sex:

male/female

Details on test animals or test system and environmental conditions:

- Source: Charles River Deutschland, Sulzfeld, Germany.
- Females nulliparous and non-pregnant: yes
- Age at study initiation: Young adult animals (approx. 10 weeks old)
- Weight at study initiation: Body weight variation was within +/- 20% of the sex mean.
- Housing: Individual housing in labeled Macrolon cages
- Diet: Free access to pelleted rodent diet (SM R/M-Z from SSNIFF® Spezialdiäten GmbH, Soest, Germany).
- Water: Free access to tap water.
- Acclimation period: At least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20.3 – 23.9ºC
- Humidity (%): 32 – 57%
- Air changes (per hr): approx 15
- Photoperiod (hrs dark / hrs light): 12/12

Deviations from the minimum level of relative humidity occurred. Laboratory historical data do not indicate an effect of the deviations.

IN-LIFE DATES: From: 02 -16 February 2012

For logistic reasons the study was rescheduled which cause a delay in the completion time (protocolled 12 February 2012). The later start has no adverse effect on the outcome of the study.

Administration / exposure

Type of coverage:

occlusive

Vehicle:

CMC (carboxymethyl cellulose)

Details on dermal exposure:

One day before exposure (Day -1) an area of approximately 5x7 cm on the back of the animal was clipped.

TEST SITE
- Area of exposure: 18 cm² (females), 25 cm² (males)
- % coverage: 10
- Type of wrap if used: The formulation was held in contact with the skin with a dressing, consisting of a surgical gauze patch (Surgy 1D)*, successively covered with aluminum foil and Coban elastic bandage. A piece of Micropore tape was additionally used for fixation of the bandages in females only.

REMOVAL OF TEST SUBSTANCE
- Washing: the skin was cleaned of residual test substance using tap water
- Time after start of exposure: 24h

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 10 mL/kg body weight.

VEHICLE
- Concentration (if solution): 1%

DOSAGE PREPARATION: The formulation (w/w) was prepared within 4 hours prior to dosing. Homogeneity was accomplished to a visually acceptable level. No correction was made for purity of the test substance.

Duration of exposure:

24 hours.

Doses:

2000 mg/kg

No. of animals per sex per dose:

5

Control animals:

no

Details on study design:

Duration of observation period following administration: 14 days
- Frequency of observations and weighing:
Mortality/Viability:Twice daily.
Body weights: Days 1 (pre-administration), 8 and 15.
Clinical signs: At periodic intervals on the day of dosing (Day 1) and once daily thereafter, until Day 15.
- Necropsy of survivors performed: At the end of the observation period, all animals were sacrificed by oxygen/carbon dioxide procedure and subjected to necropsy. Descriptions of all internal macroscopic abnormalities were recorded.

Statistics:

None.

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

No mortality occurred.

Clinical signs:

other: Hunched posture and/or chromodacryorrhoea were noted in the majority of animals on Days 1, 2 and/or 3. Scales, scabs, yellow discoloration, dry appearance and/or fissures were seen in the treated skin-area of the animals during the observation period.

Gross pathology:

No abnormalities were found at macroscopic post mortem examination of the animals.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

The dermal LD50 value of the test material in Wistar rats was established to exceed 2000 mg/kg body weight.

Executive summary:

Assessment of acute dermal toxicity with the test material in the rat was carried out following OECD TG 402 and under GLP conditions.

The test material was administered to five Wistar rats of each sex by a single dermal application at 2000 mg/kg bw for 24 hours. Animals were subjected to daily observations and weekly determination of body weight. Macroscopic examination was performed after terminal sacrifice (Day 15).

No mortality occurred. Hunched posture and/or chromodacryorrhoea were noted in the majority of animals on Days 1, 2 and/or 3. Scales, scabs, yellow discoloration, dry appearance and/or fissures were seen the in the treated skin-area of the animals during the observation period. No effect on body weight was observed and no abnormalities were found at macroscopic post mortem examination.

The dermal LD50 value of the test material in Wistar rats was established to exceed 2000 mg/kg body weight.