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Toxicological information

Acute Toxicity: dermal

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Administrative data

Endpoint:
acute toxicity: dermal
Type of information:
read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
comparable to guideline study with acceptable restrictions
Justification for type of information:
Additional documentation, provided within the IUCLID Assessment Reports (Section 13), supports the read-across approach.
Cross-reference
Reason / purpose:
read-across: supporting information
Reference
Endpoint:
acute toxicity: dermal
Type of information:
read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Justification for type of information:
Additional documentation, provided within the IUCLID Assessment Reports (Section 13), supports the read-across approach.
Reason / purpose:
read-across source
Sex:
male
Dose descriptor:
other: Approximate Lethal Dose (ALD)
Effect level:
1 500 mg/kg bw

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1970
Report Date:
1970

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 402 (Acute Dermal Toxicity)
Deviations:
yes
Remarks:
only 1 animal per dose level, only one sex tested, necropsy on only 7 of the 9 animals conducted
GLP compliance:
not specified

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): ortho-Phenylenediamine (OPD).
- Samples were obtained by chipping pieces (mainly orange-brown) from the top layers of a solidified mass of orange-brown, yellow brown, and black layers, and grinding them into a uniform mixture. When the material was dispersed into a hydrophilic ointment USP, an orange paste usually formed. On one occasion, a yellow-brownish paste formed.

Test animals

Species:
rabbit
Strain:
other: albino
Sex:
male
Details on test animals and environmental conditions:
TEST ANIMALS
- Age at study initiation: Not reported
- Weight at study initiation: 2.5-3.0 g
- Fasting period before study: None
- Housing: Not reported
- Diet (e.g. ad libitum): Not reported
- Water (e.g. ad libitum): Not reported
- Acclimation period: Not reported

ENVIRONMENTAL CONDITIONS
- Temperature (°C): Not reported
- Humidity (%): Not reported
- Air changes (per hr): Not reported
- Photoperiod (hrs dark / hrs light): Not reported

Administration / exposure

Type of coverage:
occlusive
Vehicle:
other: hydrophilic ointment or polypropylene glycol
Details on dermal exposure:
TEST SITE: Rabbits were clipped at the trunk and fitted with collars.

REMOVAL OF TEST SUBSTANCE
- Washing (if done): After 24 hours contact, wrappings were removed and the treated areas were washed with water and dried.

TEST MATERIAL
- For solids, paste formed: Yes; material suspended in polypropylene glycol and applied through a single layer of gauze wrapped around the clipped trunk. For higher doses, a 50% paste of the material in hydrophilic ointment, U.S.P., was applied directly to the clipped skin without gauze. After application, all rabbits were then wrapped with impervious film, gauze, and elastic bandage.



Duration of exposure:
24 hours
Doses:
450, 670, 1000, 1500 (in polypropylene glycol), 1500, 2250 (yellow brown paste), 2250 (orange paste), 7500 and 11000 mg/kg
No. of animals per sex per dose:
one
Control animals:
no
Details on study design:
Animals were observed for 14 days before sacrifice. Necropsies were done on 7 of the 9 animals treated, and major tissues of 6 rabbits were saved for histopathological examination. No-necropsy rabbits: dosed at 11000 mg/kg and at 1500 mg/kg of the test substance in hydrophilic ointment; necropsy only - rabbit dosed at 1500 mg/kg of the test substance in polypropylene glycol.

Tissues examined included kidney, liver, trachea, lung, brain, testes, bone marrow, spleen, thymus, gastrointestinal tract and skin.

Results and discussion

Effect levels
Sex:
male
Dose descriptor:
other: Approximate Lethal Dose (ALD)
Effect level:
1 500 mg/kg bw
Mortality:
Dose Level Mortality Ratio
(mg/kg)

450 (in 50% H.O.): 0/1
670 (in 50% H.O.): 0/1
1000 (in 50% H.O.): 0/1
1500 (in 15% DMP): 0/1
1500 (in 50% H.O.): 1/1
2250 (in 50% H.O.)
yellow brown paste: 0/1
2250 (in 50% H.O.)
orange paste: 1/1
7500 (in 50% H.O.): 1/1
11,000 (in 50% H.O.): 1/1
Clinical signs:
Clinical signs of toxicity observed included hematuria and abnormally dark urine, hyperemic eyelids, salivation, and debility.

Local signs: Irritation in most cases was at least partially obscured by residual dye. However, the rabbit dosed at 1000 mg/kg showed initial erythema and edema followed by desquamation. Initial erythema was noted at dose levels above 450 mg/kg.
Body weight:
2250 mg/kg (yellow brown paste): significant weight loss through 14 days
2250 mg/kg (orange paste): weight loss slight at 1 day, severe at 2 days
Gross pathology:
The following pathologic changes were observed at lethal doses:
Bladder - distended with red-tinged urine (gross exam)
Kidney - congestion (gross exam), inflammation and papillary necrosis (7500 mg/kg)
Liver - necrosis (2250 mg/kg)
Spleen - atrophy of lymphoid elements
Skin - necrosis of epithelium of deeper portions of hair follicles
Bone marrow - generalized necrosis
Thymus - lymphocytolysis
Small intestine - degeneration

The following pathologic changes were observed at non-lethal doses:
Kidney - papillary necrosis (2250 mg/kg)
Thymus - lymphoid atrophy at doses above 450 mg/kg
Bone marrow - generalized necrosis (2250 and 1000 mg/kg with regenerative response at 1000 mg/kg)

Applicant's summary and conclusion

Interpretation of results:
Category 4 based on GHS criteria
Conclusions:
Dermal ALD = 1500 mg/kg
Executive summary:

The Approximate Lethal Dose (ALD) was 1500 mg/kg for rabbits when the test material was administered as 50% paste in hydrophilic ointment, U.S.P. Clinical signs of toxicity included hematuria and abnormally dark urine, hyperemic eyelids, salivation, and debility. Pathologic examination was done in most cases and showed frequent tissue changes in kidney, liver, bone marrow, lymphoid tissue, small intestine and skin. Local reaction was frequently obscured by the color of the test material; however, temporary moderate to mild irritation from occluded 24 hour contact was sometimes noted. In general, the orange-brown fraction appeared to be more toxic than the yellow-brown fraction in the skin absorption test.