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Toxicological information

Acute Toxicity: dermal

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Administrative data

Endpoint:
acute toxicity: dermal
Type of information:
experimental study
Adequacy of study:
key study
Study period:
From 29 July to 29 October 1980
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Study run to a reliable method but no GLP and no guideline followed

Data source

Reference
Reference Type:
publication
Title:
Unnamed
Year:
1985
Report Date:
1985

Materials and methods

Test guideline
Qualifier:
no guideline followed
Principles of method if other than guideline:
In the main study, 76 rabbits were randomly allocated to 8 test groups, each of 4 male and 4 female rabbits and 2 control groups, each of 3 male and 3 female rabbits. Four test groups and one control group (vehicle only) were abraded at the treatment site, the remaining 4 groups were non-abraded.
GLP compliance:
not specified
Limit test:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: crystalline

Test animals

Species:
rabbit
Strain:
New Zealand White
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Cheshire Rabbits Farms
- Weight at study initiation: The mean body weight on being dosed for Phases 1, 2 and 3 was 3.03 kg (range 2.56-3.66 kg) for males and 3.11 kg (range 2.47-3.84 kg) for females. The mean body weight in the main study was 3.13 kg (range 2.35-3.63 kg) for males and 3.08 kg (range 2.45-3.73 kg) for females.
- Housing: They were housed individually in cages with a grid floor, beneath which was a peat moss filled tray.
- Diet (e.g. ad libitum): They were fed Spratt's Rabbit Diet ad libitum throughout the study.
- Water (e.g. ad libitum): Water were available ad libitum throughout the study.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 18.5°C (extremes of 15°C-23°C) for the dose ranging studies and 17°C (extremes of 14°C-20°C) for the main study.
- Humidity (%): 68% (extremes of 58%-78%) for the dose ranging studies and 64% (extremes of 53%-76%) for the main study.

IN-LIFE DATES: From 29 July to 29 October 1980

No additional data

Administration / exposure

Type of coverage:
occlusive
Vehicle:
other: 1% high viscosity CMC for Phases 2 and 3, Physiological saline for Phases 1 and 2.
Details on dermal exposure:
TEST SITE
- Area of exposure: The entire trunk of the rabbit between the fore and hind limbs.
- % coverage: Approximately 10% of the body surface.
- Type of wrap if used: The gauze was covered with an impervious covering of Sleek occlusive tape.

REMOVAL OF TEST SUBSTANCE
- Washing (if done): The wrapping was removed and the skin wiped to remove any remaining test material.
- Time after start of exposure: 24 hours

TEST MATERIAL
- Concentration (if solution): 600 mg/mL
- Constant volume or concentration used: yes

No additional data
Duration of exposure:
24 hours
Doses:
Phase 1: 600, 1800 and 3000 mg dry test substance/kg/day bw (in physiological saline)

Phase 2:
600, 1800 and 3000 mg dry test substance/kg/day bw (in physiological saline)
300, 600, 1800 and 3000 mg/kg bw (in 1% CMC)

Phase 3:
Dose ranging study: 600, 1200 and 2400 mg/kg (in CMC)
Main study: 168, 372, 816 and 1788 mg/kg (in 1% CMC)
No. of animals per sex per dose:
Phase 1: one male and one female
Phase 2: one male and one female for test substance in physiological saline, one male and one female for test substance in 1% CMC
Phase 3: one male and one female in Dose ranging study, 4 male and 4 female in Main study, 3 male and 3 female for control group
Control animals:
yes, concurrent vehicle
Details on study design:
- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Animals were weighed on the day of administration and weekly thereafter, until death or sacrifice. They were observed frequently on the day of administration and in the morning and afternoon for 14 days following administration of the test substance, when surviving animals were sacrificed.
- Necropsy of survivors performed: yes
- Other examinations performed: Histopathology: At death or sacrifice in Phase 2 and 3, selected tissues were taken for histopathological examination. The tissues taken were the liver, kidneys, spleen, heart, lungs, brain, spinal cord and 2 pieces of skin from the dorsal area and these were fixed in 10% neutral buffered formalin.
Statistics:
None stated

Results and discussion

Preliminary study:
Phase 1:
Mortality was 1/2, 2/2 and 2/2, respectively. Deaths occurred between 3 and 6 days after dosing.
Clinical signs included hyperkinesia, blood around nose, clonic convulsions, laboured breathing, vocalisation and loss of co-ordination.
At post mortem examination, the following observations were recorded; blood in nasal cavity, subdural haemorrhage between cerebellum and cerebrum, slight pitting of surface of kidneys and pale kidneys.

Phase 2:
Treatment with test substance in physiological saline resulted in 0/2, 2/2 and 2/2 deaths, respectively. Deaths occurred between 1 and 6 days after dosing.
Major clinical signs observed were clonic convulsions, hyperkinesia, miosis, laboured respiration, mydriasis, dyspnoea, cyanosis and hypokinesia.
Observations noted at the post mortem examination included red staining around nose, blood around mouth creamy particulate matter in thoracic cavity and pericardial sac fluid filled.
Treatment with test substance in high viscosity 1% CMC resulted in mortality of 1/2, 1/2, 2/2 and 2/2, respectively.
Clinical signs noted were hyperkinesia, miosis, clonic convulsions, blood around nose, vocalisation, loss of mobility and laboured breathing.
Observations noted at post mortem examination included red staining around mouth and nose, subdural haemorrhage and small blood clot on the brain.

Phase 3 (Dose ranging study):
Mortality was 1/2, 2/2 and 2/2, respectively. Deaths occurred 2 to 4 days after dosing.
Clinical signs noted were hyperkinesia, clonic convulsions, vocalisation and animal unable to move hind legs.
Observations noted at post mortem examination included extensive bruising of hind legs, broken femur, clotted blood in cervical region of spinal cord, clotted blood between cerebellum and cerebrum and dark red lungs.
Effect levelsopen allclose all
Sex:
male
Dose descriptor:
LD50
Effect level:
634.12 mg/kg bw
Based on:
test mat.
95% CL:
>= 532.49 - <= 735.75
Remarks on result:
other: Non-abraded skin
Sex:
male
Dose descriptor:
LD50
Effect level:
673.81 mg/kg bw
Based on:
test mat.
95% CL:
>= 562.34 - <= 785.28
Remarks on result:
other: Abraded skin
Sex:
female
Dose descriptor:
LD50
Effect level:
718.56 mg/kg bw
Based on:
test mat.
95% CL:
>= 595.59 - <= 841.53
Remarks on result:
other: Non-adraded skin
Sex:
female
Dose descriptor:
LD50
Effect level:
1 336.7 mg/kg bw
Based on:
test mat.
95% CL:
>= 414.56 - <= 1 758.84
Remarks on result:
other: Abraded skin
Sex:
male/female
Dose descriptor:
LD50
Effect level:
982.03 mg/kg bw
Based on:
test mat.
95% CL:
>= 861.46 - <= 1 102.6
Remarks on result:
other: Non-abraded/abraded skin
Mortality:
Mortality in the non-abraded groups was 0/8, 0/8, 4/8 and 8/8 for each dose group, respectively. Mortality in the abraded groups was 0/8, 0/8, 3/8 and 7/8 for each dose group, respectively. One female non-abraded control animal died 10 days after dosing with vehicle only.
Clinical signs:
Clinical signs included hyperkinesia, mydriasis, hypokinesia, clonic convulsion, miosis, aggressive, timid, left hind limb atiff and unable to move, vocalisation, prostration in non-abraded and abraded groups, also noted blood around nose and mouth, difficulty in breathing and cyanosis in abraded groups.
Body weight:
No information provided
Gross pathology:
There was no evidence of broken back in non-abraded and abraded groups.
Other findings:
Histopathological symptoms included congestion, centrilobular necrosis/degeneration, increased cellularity, eosinophilic cytoplasm in liver; congestion and chronic nephropathy in kidney; congestion, alveolar haemorrhage, alveolar exudation and alveolar degeneration in lung; white pulp depletion and red pulp depletion in spleen.

Applicant's summary and conclusion

Interpretation of results:
toxic
Remarks:
Migrated information Criteria used for interpretation of results: EU
Conclusions:
The dermal Median Lethal Doses (LD50) for HMX were calculated as 634.12 and 718.56 mg/kg for male and female New Zealand White rabbits on non abraded skin, respectively. The dermal LD50 was 982.03 mg/kg for male and female New Zealand White rabbits on non-abraded/abraded skin.