Dibutyl phosphonate

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From June 20 to October 10, 1977

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1977

Report date:

1977

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 434 (Acute Dermal Toxicity - Fixed Dose Procedure)

Deviations:

no

GLP compliance:

no

Test type:

fixed dose procedure

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Dibutyl phosphonate

EC Number:

217-316-1

EC Name:

Dibutyl phosphonate

Cas Number:

1809-19-4

Molecular formula:

C8H19O3P

IUPAC Name:

dibutyl phosphonate

Test material form:

liquid

Test animals

Species:

rabbit

Strain:

New Zealand White

Sex:

male

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Weight at study initiation: 2-3 kg

Administration / exposure

Type of coverage:

open

Vehicle:

unchanged (no vehicle)

Details on dermal exposure:

TEST SITE
- Area of exposure: back clipped free of hair
- % coverage: 10 %
- Abrasion: 2-3 cm over the area of exposure; the abrasions were made sufficiently deep to penetrate the stratum corneum, but not deep enough to disturb the derma.
- Type of wrap if used: no data

Duration of exposure:

72 hours

Doses:

4000 and 5000 mg/kg bw

No. of animals per sex per dose:

12 males per doses

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations: 1, 3, 6, 24, 48, 72 hours and daily thereafter for a total of 14 days.

Results and discussion

Effect levels

Effect levels 1

Sex:

male

Dose descriptor:

LD0

Effect level:

ca. 4 000 mg/kg bw

Based on:

test mat.

Effect levels 2

Sex:

male

Dose descriptor:

LD50

Effect level:

ca. 5 000 mg/kg bw

Based on:

test mat.

Mortality:

Yes, six animals at dose 5000 mg/kg, no mortality during administration of 4000 mg/kg bw.

Clinical signs:

other: Edema, erythema and eschar.

Applicant's summary and conclusion

Interpretation of results:

other: Not classified according to CLP Regulation (EC no. 1272/2008)

Conclusions:

LD50 (dermal, rabbit) = 5000 mg/kg bw
LD0 (dermal, rabbit) = 4000 mg//kg bw

Executive summary:

The acute dermal toxicity of the test item was evaluated in an experimental study according to a method equivalent to the OECD Guideline 434, following the fixed dose procedure. 5000 mg/kg bw of test item was applied to the clipped, abraded skin of 12 male New Zealand albino rabbits for 72 hours, then surviving animals were observed for 14 days. The abrasion was performed 2-3 cm over the area of exposure, equivalent to approximately 10 % coverage; sufficiently deep to penetrate the stratum corneum, but not deep enough to disturb the derma. A subsequent group of rabbits was exposed in the same way to 4000 mg/kg bw.

Clinical signs included oedema, erythema and mortality in 6 out of 12 animals from the high-dose group. At the dose level of 4000 mg/kg bw, the test item produced oedema, erythema and eschar, but no mortality. The LD50 is therefore considered to be 5000 mg/kg bw, and the LD0 is considered to be 4000 mg/kg bw.