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Toxicological information

Acute Toxicity: inhalation

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Administrative data

Endpoint:
acute toxicity: inhalation
Type of information:
experimental study
Adequacy of study:
disregarded due to major methodological deficiencies
Reliability:
3 (not reliable)
Rationale for reliability incl. deficiencies:
other: significant methodological deficiencies

Data source

Referenceopen allclose all

Reference Type:
study report
Title:
Unnamed
Year:
1974
Reference Type:
other company data
Title:
Unnamed
Year:
2003
Reference Type:
other: Review
Title:
1,2,3-Benzotriazole
Author:
Health Council of the Netherlands: Dutch expert committee on occupational standards (DECOS)
Year:
2000
Bibliographic source:
ISBN: 90-5549-348-1

Materials and methods

Test guideline
Qualifier:
no guideline followed
Principles of method if other than guideline:
Five groups each consisting of 10 animals received a single three hour exposure of five different aerosole concentrations.
The animals were observed for fourteen days post-exposure.
GLP compliance:
not specified
Test type:
standard acute method

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: particulate/powder
Remarks:
migrated information: powder
Details on test material:
- Name of test material (as cited in study report): Benzotriazole Photo Grade
- Physical state: solid, white powder
- Sample No.: 1422

Test animals

Species:
rat
Strain:
Sprague-Dawley
Sex:
male
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Charles River Breeding Laboratories
- Weight at study initiation: 301-380 g
- Housing: caged in groups of ten
- Diet (e.g. ad libitum): Charles River cubed diet, ad libitum
- Water (e.g. ad libitum): tap water ad libitum
- Acclimation period: on week

Administration / exposure

Route of administration:
inhalation: aerosol
Type of inhalation exposure:
whole body
Vehicle:
clean air
Details on inhalation exposure:
Aerosol Generation and Exposure Methods:
Preliminary experiments indicated that due to the physical characteristics
of the powder. it was not possible to generate a concentration
high enough to produce death in the experimental animals. Therefore.
w1th assistance from the sponsor. an aerosol generation system was
designed which would simulate the aerosol produced during the manufacturing
process.
Figure No. 1 shows a schematic drawing of the aerosol generation
system. The system operates as follows. Approximately five hundred
(500) milliliters of melted benzotriazole is placed in the gas washing
bottle. The bottle is then placed in an oil bath at 195°C (190 - 200°C).
This temperature is maintained by the immersion heater and the hot plate.
A controlled air flow rate is provided to the bottom of the gas washing
bottle. The benzotriazole vapor-laden air is taken from the top of the
gas washing bottleK diluted, and cooled with admixture of a controlled
flow of clean dry air. To prevent condensation of benzotriazole in the
Teflon delivery tube, it was necessary to heat this tube to 200°C also.
However, even with this precaution the final few centimeters of the
delivery tube had to be cleaned of solid benzotriazole every hour. This
system produced a very fine white aerosole. Chamber concentration was
controlled by varying the air flow rate to the gas washing bottle.
Analytical verification of test atmosphere concentrations:
yes
Duration of exposure:
3 h
Concentrations:
0.78/1.46/2.03/2.23/2.71 mg/L
No. of animals per sex per dose:
10
Control animals:
no
Details on study design:
- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: every 7 days
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight, gross pathology
Statistics:
95 % confidence limits

Results and discussion

Effect levels
Sex:
male
Dose descriptor:
LC50
Effect level:
1.91 mg/L air (analytical)
Based on:
test mat.
95% CL:
>= 1.59 - <= 2.29
Exp. duration:
3 h
Mortality:
Exposure concentration mg/l // Percent mortality
0.78 // 0
1.46 // 10
2.03 // 20
2.23 // 50
2.71 // 100
All but one death occurred during the final half-hour of exposure. One animal was found dead the morning after exposure in the group exposed to 2.23 mg/l
Clinical signs:
During exposure, the only pharmacotoxic sign observed was deep abdominal breathing with open mouth gasping apparent during exposure to the two highest concentrations.
After exposure, all surviving animals appeared normal and healthy.
Body weight:
The surviving animals appeared to gain weight normally.
Gross pathology:
The cut trachea exhibited a very severe accumulation of white frothy fluid,
The lungs exhibited a moderate to severe incidence of dark red hemorrhagic areas in all lobes. The cut surface of the lungs did not indicate the presence of pulmonary edema.

Applicant's summary and conclusion

Interpretation of results:
other: disambigious
Remarks:
Criteria used for interpretation of results: expert judgment
Conclusions:
The drawbacks to aerolise 1H-benzotriazole (heating to 200°C) make it difficult to interprete the study:
From the Information given, it is not possible to distinguish if the rats died because of the heat of the aerosol or its toxic potential.