Silicic acid, lithium magnesium sodium salt

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Test carried out by GLP compliant laboratory to recognised validated methods by trained personnel

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1988

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: Draize Test Dermal Toxicity FDA 1975

Deviations:

yes

Remarks:

Modified Draize test

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Silicic acid, lithium magnesium sodium salt

EC Number:

258-476-2

EC Name:

Silicic acid, lithium magnesium sodium salt

Cas Number:

53320-86-8

Molecular formula:

Na0.7[Li0.3Mg5.5Si8O20(OH)4]

IUPAC Name:

magnesium(2+) lithium(1+) sodium bis(oxosilanebis(olate))

Details on test material:

Optigel SH is another commercial name for Laponite T2 and is the same test substance

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

Animals were acclimated at least 4 days prior to test. Housed in galvanised or s.s cages and kept in a 12hr day/night cycle. Room temperaturs kept between 65-75 deg F. Fed and watered. 24 hours prior to test the animals were re-examined. Any with skin problems or in poor health were not used.

Test system

Type of coverage:

occlusive

Preparation of test site:

other: two sites per animal, one shaved only, the other shaved and abraded

Vehicle:

physiological saline

Controls:

not required

Amount / concentration applied:

0.5 g of test material moistened with saline were applied to each test site

Duration of treatment / exposure:

Wrapping and test article removed after 24 hours. Remaining test article was gently washed from the skin with water and dried with paper towel.

Observation period:

Test sites were examined after 24 and 72 hours

Number of animals:

Six

Results and discussion

In vivo

Results

Irritation parameter:

primary dermal irritation index (PDII)

Basis:

mean

Time point:

other: 24 hours and 72 hous after application

Score:

0.18

Reversibility:

no data

Applicant's summary and conclusion

Interpretation of results:

not irritating

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

This substance is not a primary dermal irritant to rabbits under the consition of the test. A score in the range 0.1-0.9 is classed as "potential for slight irritation, rarely irritating to people - no warning required"