Registration Dossier

Administrative data

Endpoint:
acute toxicity: dermal
Type of information:
experimental study
Adequacy of study:
key study
Study period:
06 January 2010 - 20 January 2010
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2010
Report date:
2010

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to guideline
Guideline:
OECD Guideline 402 (Acute Dermal Toxicity)
Deviations:
no
Qualifier:
according to guideline
Guideline:
EU Method B.3 (Acute Toxicity (Dermal))
Deviations:
no
GLP compliance:
yes (incl. QA statement)
Test type:
standard acute method
Limit test:
yes

Test material

Constituent 1
Reference substance name:
Calcium carbonate (nano)
IUPAC Name:
Calcium carbonate (nano)
Details on test material:
- Name of test material (as cited in study report): Calcium carbonate (nano)
- Description: White powder
- Batch No.: GICM014427
- Storage condition of test material: Room temperature in the dark

The nano form of calcium carbonate was tested because this form was anticipated to represent the worst case as the smaller size particles are more likely to be transported through the skin.

Test animals

Species:
rat
Strain:
Wistar
Sex:
male/female
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: Harlan Laboratories UK Limited, Bicester, Oxon, UK
- Age at study initiation: 8-12 weeks
- Weight at study initiation: at least 200 g
- Fasting period before study: No data
- Housing: The animals were housed in suspended solid floor polypropylene cages furnished with woodflakes. The animals were housed individually during the 24-hour exposure period and in groups of five, by sex, for the remainder of the study.
- Diet (e.g. ad libitum): Food (2014 Teklad Global Rodent diet) was available ad libitum.
- Water (e.g. ad libitum): Mains drinking water was available ad libitum.
- Acclimation period: At least 5 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19-25 °C
- Humidity (%): 30-70%
- Air changes (per hr): at least fifteen changes per hour
- Photoperiod (hrs dark / hrs light): twelve hours continuous light (06:00 to 18:00) and twelve hours darkness

Administration / exposure

Type of coverage:
semiocclusive
Vehicle:
arachis oil
Details on dermal exposure:
TEST SITE
- Area of exposure: back and flanks of each animal
- % coverage: approximately 10% of the total body surface area
- Type of wrap if used: A piece of surgical gauze was placed over the treatment area and semi-occluded with a piece of self-adhesive bandage.


REMOVAL OF TEST SUBSTANCE
- Washing (if done): After the 24-hour contact period the bandage was carefully removed and the treated skin and surrounding hair wiped with cotton wool moistened with arachis oil BP to remove any residual test material.
- Time after start of exposure: 24 h


TEST MATERIAL
The appropriate amount of test material, moistened with arachis oil BP, was applied as evenly as possible to an area of shorn skin using a graduated syringe.
Duration of exposure:
24 h
Doses:
2000 mg/kg
No. of animals per sex per dose:
5 animals/ sex/ dose
Control animals:
not specified
Details on study design:
The animals were observed for deaths or overt signs of toxicity 0.5, 1, 2 and 4 hours after dosing and subsequently once daily for fourteen days.

After removal of the dressings and subsequently once daily for fourteen days, the test sites were examined for evidence of primary irritation and scored according to the scale from Draize (1977).

Individual bodyweights were recorded prior to application of the test material on Day 0 and on Days 7 and 14.

At the end of the study the animals were killed by cervical dislocation. All animals were subjected to gross necropsy. This consisted of an external examination and opening of the abdominal and thoracic cavities. The appearance of any macroscopic abnormalities was recorded. No tissues were retained.

Results and discussion

Effect levels
Sex:
male/female
Dose descriptor:
LD50
Effect level:
> 2 000 mg/kg bw
Mortality:
There were no deaths.
Clinical signs:
There were no signs of systemic toxicity or dermal irritation.
Body weight:
All animals showed expected gains in bodyweight over the study period.
Gross pathology:
No abnormalities were noted at necropsy.

Any other information on results incl. tables

Table 1: Individual clinical observations and mortality data

Dose level (mg/kg)

Animal no. & sex

Effects noted after initiation of exposure (hours)

Effects noted after initiation of exposure (days)

0.5

1

2

4

1

2

3

4

5

6

7

8

9

10

11

12

13

14

2000

Males

(1-1, 1-2, 1-3 & 1-4)

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

Females

(2-1, 2-2, 2-3 & 2-4)

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0 = no signs of systemic toxicity

 

 

Table 2: Individual dermal reactions – Males

Dose level (mg/kg)

Animal no. & sex

Observation

Effects noted after initiation of exposure (days)

1

2

3

4

5

6

7

8

9

10

11

12

13

14

2000

Males

(1-1, 1-2, 1-3 & 1-4)

Erythema

0

0

0

0

0

0

0

0

0

0

0

0

0

0

Oedema

0

0

0

0

0

0

0

0

0

0

0

0

0

0

Other

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0 = No reactions

 

 

Table 3: Individual dermal reactions – Females

Dose level (mg/kg)

Animal no. & sex

Observation

Effects noted after initiation of exposure (days)

1

2

3

4

5

6

7

8

9

10

11

12

13

14

2000

Females

(2-1, 2-2, 2-3 & 2-4)

Erythema

0

0

0

0

0

0

0

0

0

0

0

0

0

0

Oedema

0

0

0

0

0

0

0

0

0

0

0

0

0

0

Other

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0 = No reactions

 

 

Table 4: Individual bodyweights and weekly bodyweight changes

Dose level (mg/kg)

Animal no. & sex

Bodyweight (g) at Day

Bodyweight change (g) during week

0

7

14

1

2

2000

1-0

Male

232

256

278

24

22

1-1

Male

235

255

270

20

15

1-2

Male

242

268

288

26

20

1-3

Male

224

246

270

22

24

1-4

Male

234

261

279

27

18

2-0

Female

220

228

239

8

11

2-1

Female

203

204

216

1

12

2-2

Female

211

216

218

5

2

2-3

Female

217

220

230

3

10

2-4

Female

212

213

220

1

7

 

 

Table 5: Individual necropsy findings

Dose level (mg/kg)

Animal no. & sex

Macroscopic observations

2000

Males

(1-1, 1-2, 1-3 & 1-4)

No abnormalities detected

Females

(2-1, 2-2, 2-3 & 2-4)

No abnormalities detected

 

 

Applicant's summary and conclusion

Interpretation of results:
not classified
Remarks:
Migrated information Criteria used for interpretation of results: EU
Conclusions:
The acute dermal median lethal dose (LD50) of the test material in the Wistar strain rat was found to be greater than 2000 mg/kg bodyweight.