Cesium formate

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From January 14, 1997 to January 21, 1997

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1997

Report date:

1997

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EPA OTS 798.4470 (Acute Dermal Irritation)

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Cesium formate

EC Number:

222-492-8

EC Name:

Cesium formate

Cas Number:

3495-36-1

Molecular formula:

HCO2.Cs, Cs+HCOO-, CH2O2.Cs

IUPAC Name:

Caesium formate

Test material form:

liquid

Details on test material:

Name of test material (as cited in study report): Cesium Formate
Physical state: Clear colorless liquid
Storage condition of test material: Room temperature

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Myrtle's Rabbitry Incorporated (U.S.D.A. licensed supplier) 4678 Bethesda Road Thompson Station, TN 37179
- Age at study initiation: Adult
- Weight at study initiation: 2.516 to 2.728 kg
- Housing: Housed singly in wire mesh suspension cage
- Diet (e.g. ad libitum): Teklad Hi-Fiber Rabbit Diet
- Water (e.g. ad libitum): Tap water
- Acclimation period: 5 d

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 61- 72 °F
- Humidity (%): 30- 70 %
- Air changes (per hr): Not reported
- Photoperiod (hrs dark / hrs light): 12 h light/12 h dark cycle

Test system

Type of coverage:

semiocclusive

Preparation of test site:

other: One day prior to test substance administration, hair from dorsal surface of the trunk was clipped using an electric clipper. The test site was inspected for any signs of irritation, interfering lesions or defects before the application.

Vehicle:

unchanged (no vehicle)

Controls:

no

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.5 mL
- Concentration (if solution): Undiluted

Duration of treatment / exposure:

4 h

Observation period:

The application sites were observed approximately ½ -1, 24, 48 and 72 h after removal of test substance. For animals exhibiting irritation at the 72 h reading, an additional skin reading was conducted on Day 7 to check for the reversibility of the irritation.

Number of animals:

Six (three males and three females)

Details on study design:

TEST SITE
- Area of exposure: 1 x 1 inch
- % coverage: Not reported
- Type of wrap if used: Two-layered 1 inch2 gauze patch

REMOVAL OF TEST SUBSTANCE
- Washing (if done): Using a paper towel moistened with tap water
- Time after start of exposure: 4 h

SCORING SYSTEM: According to Draize (1995). Appraisal of the safety of chemicals in food, drugs and cosmetics. Association of the food and drug officials of the United States. Austin, Texas

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Basis:

animal: mean

Time point:

other: 0.5 -1 h

Score:

ca. 1.67

Reversibility:

fully reversible within: 7 d

Remarks on result:

other: 0.5 -1 h

Results 2

Irritation parameter:

erythema score

Basis:

animal: mean

Time point:

24 h

Score:

ca. 1.17

Reversibility:

fully reversible within: 7 d

Results 3

Irritation parameter:

erythema score

Basis:

animal: mean

Time point:

48 h

Score:

ca. 0.83

Reversibility:

fully reversible within: 7 d

Results 4

Irritation parameter:

erythema score

Basis:

animal: mean

Time point:

72 h

Score:

ca. 0.5

Reversibility:

fully reversible within: 7 d

Results 5

Irritation parameter:

edema score

Basis:

animal: mean

Time point:

other: 0.5 -1 h

Score:

ca. 1.67

Reversibility:

fully reversible within: 7 d

Remarks on result:

other: 0.5-1 h

Results 6

Irritation parameter:

edema score

Basis:

animal: mean

Time point:

24 h

Score:

ca. 0.67

Reversibility:

fully reversible within: 7 d

Results 7

Irritation parameter:

edema score

Basis:

animal: mean

Time point:

48 h

Score:

ca. 0.5

Reversibility:

fully reversible within: 7 d

Results 8

Irritation parameter:

edema score

Basis:

animal: mean

Time point:

72 h

Score:

ca. 0.33

Reversibility:

fully reversible within: 7 d

Irritant / corrosive response data:

No evidence of corrosion or necrosis was observed in the treated animals.
All animals exhibited slight to well defined erythema and slight edema at ½ to 1 h reading. 3/6 animals were recovered by 72 h and the remaining by Day 7. The primary irritation index was calculated as 1.8.

Other effects:

Desquamation in texture of the skin was also observed.

Any other information on results incl. tables

Individual scores

Score for each rabbit for erythema and eschar formation
	No. 1	No. 2	No. 3	No. 4	No. 5	No. 6	Total Score	Average Score
½ -1 h	2	2	2	1	2	1	10	1.67
24 h	1	1	1	1	2	1	7	1.17
48 h	1	1	0	1	1	1	5	0.83
72 h	1	0	0	1	1	0	3	0.50
Day 7	0	ND	ND	OW	OW	ND	0	0.00
Score for each rabbit for edema formation
	No. 1	No. 2	No. 3	No. 4	No. 5	No. 6	Total Score	Average Score
½ -1 h	2	2	1	1	2	2	10	1.67
24 h	1	1	0	0	1	1	4	0.67
48 h	1	1	0	0	1	0	3	0.50
72 h	1	0	0	0	1	0	2	0.33
Day 7	0	ND	ND	0	0	ND	0	0.00

Maximum score for erythema and eschar formation: 2, and Maximum score for edema formation: 2

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

Under the study conditions no evidence of corrosion or necrosis was observed in the treated animals. All animals exhibited only slight to well defined erythema and slight edema, which recovered in three animals by 72 h and in the remaining three animals by Day 7.

Executive summary:

A study was conducted to determine the skin irritation potential of the test substance in New Zealand White rabbits according to OECD Guideline 404 and EPA Pesticide Assessment Guideline, Subdivision F (81-5) EPA Health Effects Testing Guideline (TSCA Guideline No 798.4470), in compliance with GLP. Following the test site preparation by clipping hair one day prior to application, 0.5 mL of undiluted test substance was applied to the dorsal skin surface under a gauze patch which was then covered by a semiocclusive dressing around the trunk. After 4 h of exposure period, the test substance was removed and the animals were observed during 72 h for skin reactions and additionally until Day 7 for unresolved skin reactions. Scoring was conducted according to the Draize method. Under the study conditions, no evidence of corrosion or necrosis was observed in the treated animals. All animals exhibited only slight to well defined erythema and slight edema, which recovered in three animals by 72 h and in the remaining three animals by Day 7. The primary irritation index was calculated as 1.8(Harrod, 1997).