5-(diisopropylamino)-2-[[4-(dimethylamino)phenyl]azo]-3-methyl-1,3,4-thiadiazolium acetate

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

Type of information:

other: experimental results on similar substance

Adequacy of study:

key study

Study period:

From June 21 to July 12, 2017

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Version / remarks:

adopted on 24 February 1987

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.3 (Acute Toxicity (Dermal))

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.1200 (Acute Dermal Toxicity)

Deviations:

no

Test guideline 4

Qualifier:

according to guideline

Guideline:

other: EPA OPPTS Methods 870.1000 “Acute Toxicity Testing - Background”

Deviations:

no

GLP compliance:

yes

Test type:

standard acute method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Similar Substance 02

IUPAC Name:

Similar Substance 02

Test material form:

solid: particulate/powder

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
Species and strain: rat, Hsd: Sprague Dawley SD
Sex: males and females (nulliparous and non-pregnant)
Age at order: 6 to 8 weeks old (first batch used for 1000 mg/kg bw); 6 to 7 weeks old (second batch used for 2000 mg/kg bw)
Weight ordered: 176 to 200 g (first batch used for 1000 mg/kg bw); 150 to 174 g (second batch used for 2000 mg/kg bw)
Supplier: Envigo RMS srl, San Pietro al Natisone (UD), Italy
Breeder: Envigo RMS B.V., Kreuzelweg 53, 5961 NM Horst, Netherlands
Date of arrival: 14 June 2017 (both batches)
Weight range at arrival: 161.4 to 189.2 g (M); 184.2 to 191.7 g (F) (first batch used for 1000 mg/kg bw); 168 to 171 g (M); 159 to 168 g (F) (second batch used for 2000 mg/kg bw)
Acclimatisation period: at least 5 days
Veterinary health check: During acclimatisation period

ENVIRONMENTAL CONDITIONS
Animals per cage: up to 5 of one sex during acclimatisation; individually caged during the study
Housing: clear polysulphone H-Temp solid bottomed cages (Tecniplast Gazzada S.a.r.l., Buguggiate, VA, Italy) measuring 59.5×38×20 cm during acclimatisation period and 42.5×26.6×18.5 cm during the study with nesting material provided into suitable bedding bags.
Cage control: daily inspected and changed as necessary (at least 3 times/week)
Water: drinking water supplied to each cage via a water bottle
Water supply: ad libitum
Diet: 4 RF 18 (Mucedola S.r.l., Via G. Galilei, 4, 20019, SettimoMilanese (MI) Italy)
Diet supply: ad libitum throughout the study
Room lighting: artificial (fluorescent tubes), daily light/dark cycle of 12/12 hours
Air changes: approximately 15 to 20 air changes per hour
Temperature range: 22 ± 2 °C
Relative humidity range: 55 ± 15 %

Administration / exposure

Type of coverage:

semiocclusive

Details on dermal exposure:

TEST SITE
- Area of exposure: dorsal surfaces of the trunk
- % coverage: ca. 10 % of body surface
- Type of wrap if used: elastic adhesive bandage and gauze patch

REMOVAL OF TEST SUBSTANCE
- Washing: yes, with cotton wool soaked with lukewarm water
- Time after start of exposure: 24 hours

Duration of exposure:

The animals remained in contact with the test item for 24 hours

Doses:

1000 and 2000 mg/kg body weight

No. of animals per sex per dose:

5 males anf 5 females at 1000 mg/kg body weight
5 males anf 5 females at 2000 mg/kg body weight

Control animals:

not required

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: animals were observed for clinical signs the day of dosing: on dosing, approximately 1 h after dosing, approximately 2 h after dosing and approximately 4 h after dosing. Daily thereafter for a total of 14 days.
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat. (total fraction)

Remarks on result:

no indication of skin irritation up to the relevant limit dose level

Mortality:

No mortality occurred

Clinical signs:

No signs of toxicity were observed in male or female animals during the observation period. Only blue staining in treated site, due to the colour of the substance, was observed in all male and female animals from day 2 up to day 15.

Body weight:

The body weight changes observed during the study were within the expected range for this species and age of animals.

Gross pathology:

Only blue staining on the treatment site, due to the colour of the substance, was found at necropsy in all animals at termination of the study.

Applicant's summary and conclusion

Interpretation of results:

other: not classified according to the CLP Regulation (EC 1907/2006)

Conclusions:

LD0 = 2000 mg/kg
LD50 > 2000 mg/kg

Executive summary:

Method

Acute dermal toxicity was investigated upon application of a single dose to rats followed by a 14-day observation period. A single dose of 1000 mg/kg bw was applied to a group of 5 male and 5 female animals for 24 hours. After 14 days, all animals were killed and subjected to necropsy to examine macroscopic changes.

A second group of 5 male and 5 female animals was then dosed at 2000 mg/kg body weight for 24 hours, which were also necropsied after 14 days of observation.

Results

As for the first group, no mortality occurred and no signs of toxicity were observed in male or female animals during the observation period.

As for the second group, no mortality occurred and no signs of toxicity were observed in male or female animals during the observation period. Body weight changes observed during the study were within the expected range for this species and age of animals. Only blue staining on the treatment site, due to the colour of the substance, was found at necropsy in all animals at termination of the study.

Due to the lack of mortality, LD0 = 2000 mg/kg and LD50 > 2000 mg/kg bw was established.