Registration Dossier

Administrative data

Endpoint:
acute toxicity: inhalation
Type of information:
experimental study
Adequacy of study:
key study
Study period:
27 December 2017 - 21 February 2018
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2018
Report Date:
2018

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 403 (Acute Inhalation Toxicity)
Deviations:
no
Qualifier:
according to
Guideline:
EPA OPPTS 870.1300 (Acute inhalation toxicity)
Qualifier:
according to
Guideline:
EU Method B.2 (Acute Toxicity (Inhalation))
Deviations:
no
GLP compliance:
yes
Test type:
fixed concentration procedure
Limit test:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: particulate/powder
Specific details on test material used for the study:
Composition: STB-FR (Benzenesulfonic acid, 2,4,5-trichloro-, sodium salt)
Lot #: 1710-06
Purity: 90.5%
CAS# 53423-65-7
EC# 258-548-3
Physical Description: White powder
pH: 7.11
Stability: Test substance was expected to be stable for the duration of testing.
Expiration Date: October 2019

Test animals

Species:
rat
Strain:
Sprague-Dawley
Sex:
male/female
Details on test animals and environmental conditions:
Animals were singly housed in suspended stainless steel caging, which conforms to the size recommendations in the most recent Guide for the Care and Use of Laboratory Animals (Natl. Res. Council, 2011). Animal Room Temperature and Relative Humidity Ranges were recorded at 20-26ºC and 45-59%, respectively.

Administration / exposure

Route of administration:
inhalation: dust
Type of inhalation exposure:
nose only
Vehicle:
air
Mass median aerodynamic diameter (MMAD):
3.36 µm
Geometric standard deviation (GSD):
2.46
Analytical verification of test atmosphere concentrations:
yes
Remarks:
Gravimetric
Duration of exposure:
4 h
Concentrations:
5.15 mg/L +/- 0.25
No. of animals per sex per dose:
5
Control animals:
no
Details on study design:
After establishing the desired generation procedures during the pre-test trials, ten healthy rats (5/sex) were exposed to the test atmosphere for 4 hours. Chamber concentration and particle size distributions of the test atmosphere were determined periodically during the exposure period. The animals were observed for mortality, signs of gross toxicity, and behavioral changes at least once daily for 14 days following exposure. Body weights were recorded prior to exposure (initial) and again on Days 1, 3, 7, and 14 (terminal). Necropsies were performed on all animals at terminal sacrifice.
Statistics:
Statistical analysis was limited to the calculation of the mean and standard deviation.

Results and discussion

Effect levels
Key result
Sex:
male/female
Dose descriptor:
LC50
Effect level:
> 5.15 mg/L air (analytical)
Based on:
test mat.
Exp. duration:
4 h
Mortality:
None
Clinical signs:
other: All rats exhibited irregular respiration upon removal from the exposure tube and at 1.5 hours post-exposure, but recovered by Day 1 and appeared active and healthy for the remainder of the 14-day observation period.
Body weight:
All animals gained body weight throughout the the 14-day study period.
Gross pathology:
No gross abnormalities were noted for any of the animals when necropsied at the conclusion of the 14-day observation period.

Any other information on results incl. tables

GRAVIMETRIC CHAMBER CONCENTRATIONS:

Target

Concentration

(mg/L)

Sample Number

Time of Sample

(hour)

Mass

Collected

(mg)

Airflow Sampled (Lpm)

Collection Time

(min)

Exposure Concentration (mg/L)

5.0

1

0.5

20.6

4.0

1

5.15

2

1.0

22.0

4.0

1

5.50

3

2.0

19.3

4.0

1

4.83

4

2.5

20.0

4.0

1

5.00

5

3.5

20.1

4.0

1

5.03

6

3.75

21.5

4.0

1

5.38

Average ± Standard Deviation

5.15 ± 0.25

SUMMARY OF PARTICLE SIZE DISTRIBUTION:

Sample No.

Time of

Sample

(hours)

Collection

Time

(minutes)

Mass Median Aerodynamic Diameter

(µm)

Geometric Standard Deviation

1

1.5

1

3.34

2.47

2

3

1

3.38

2.44

Average

3.36

2.46

Applicant's summary and conclusion

Interpretation of results:
GHS criteria not met
Conclusions:
The 4-hour LC50 for male and female Sprague-Dawley rats was determined to be >5.15 mg/L.
Executive summary:

In a GLP Acute Inhalation (nose-only) guideline study with male and female Sprague-Dawley rats conducted according to OECD Guideline 403, OPPTS 870.1300, and EC method B.2, the 4 -hour LC50 was determined to be >5.15 mg/L. After establishing the desired generation procedures during the pre-test trials, ten healthy rats (5/sex) were exposed to the test atmosphere for 4 hours. Chamber concentration and particle size distributions of the test atmosphere were determined periodically during the exposure period. The animals were observed for mortality, signs of gross toxicity, and behavioral changes at least once daily for 14 days following exposure. Body weights were recorded prior to exposure (initial) and again on Days 1, 3, 7, and 14 (terminal). Necropsies were performed on all animals at terminal sacrifice. All animals survived exposure to the test atmosphere and gained body weight during the study. Following exposure, all rats exhibited irregular respiration. However, all animals recovered by Day 1 and appeared active and healthy for the remainder of the 14-day observation period. No gross abnormalities were noted for any of the animals when necropsied at the conclusion of the 14-day observation period.The gravimetric chamber concentration was 5.15 mg/L. The average mass median aerodynamic diameter was estimated to be 3.36 µm based on graphic analysis of the particle size distribution as measured with a 1 ACFM Andersen Ambient Particle Sizing Sampler with an average geometric standard deviation of 2.46.