Silicic acid (H2Si2O5), barium salt (1:1), lead-doped

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

16-30 December 2009

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: This study has been performed according to OECD and/or EC guidelines and according to GLP principles.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Report date:

2010

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

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: Japanese Ministry of Agriculture, Forestry and Fisheries (JMAFF), 12 Nousan, Notification No 8147, November 2000; including the most recent partial revisions.

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Silicic acid (H2Si2O5), barium salt (1:1), lead-doped

EC Number:

272-271-5

EC Name:

Silicic acid (H2Si2O5), barium salt (1:1), lead-doped

Cas Number:

68784-75-8

Molecular formula:

BaSi2O5::Pb

IUPAC Name:

barium(2+) {[oxido(oxo)silyl]oxy}silanoylolate λ²-plumbane

Details on test material:

- Name of test material (as cited in study report): Silicic acid(H2Si2O5), barium salt(1:1), lead-doped
- Substance type: White powder
- Physical state: Solid
- Analytical purity: 100%
- Purity test date: 20-oct-2010
- Lot/batch No.: NP-800-11-232
- Expiration date of the lot/batch: 16 October 2010
- Stability under storage conditions: Stable
- Storage condition of test material: At room temperature in the dark
- pH: (1% in water, indicative range) 9.5 – 9.6
- Stability in vehicle (1% Aq. Carboxymethyl cellulose): Unknown

Test animals

Species:

rat

Strain:

other: Wistar strain, Crl:WI (Han)

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Deutschland, Sulzfeld, Germany
- Age at study initiation: approx. 8 weeks old
- Weight at study initiation: Body weight variation did not exceed +/- 20% of the sex mean.
- Housing: Individually housed in labeled Macrolon cages (MIII type, height 18 cm.) containing sterilized sawdust as bedding material (Woody-Clean type 3/4, Tecnilab-BMI BV, Someren, The Netherlands) and paper as cage-enrichment (Enviro-dri, Tecnilab-BMI BV, Someren, The Netherlands).
- Diet (e.g. ad libitum): Free access to pelleted rodent diet (SM R/M-Z from SSNIFF® Spezialdiäten GmbH, Soest, Germany).
- Water (e.g. ad libitum): Free access to tap water.
- Acclimation period: The acclimatization period was at least 5 days before the start of treatment under laboratory conditions.
- Health inspection: A health inspection was performed prior to treatment, to ensure that the animals were in a good state of health. Special attention was paid to the skin to be treated, which was intact and free from any abnormality.

Results of analysis for diet (nutrients and contaminants), sawdust, paper and water were assessed and did not reveal any findings that were considered to have affected the study integrity. All certificates and results of analysis are retained in the NOTOX archives.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 18.4 – 21.7ºC
- Humidity (%): 31 - 88%
Cleaning procedures in the room might have caused the temporary fluctuations above the optimal maximum level of 70% for relative humidity. Based on laboratory historical data, these fluctuations were considered not to have affected the study integrity
- Air changes (per hr): approximately 15 air changes per hour
- Photoperiod (hrs dark / hrs light): 12 hours artificial fluorescent light and 12 hours darkness per day.

IN-LIFE DATES: From: 16 december 2009 To: 30 december 2009

Administration / exposure

Type of coverage:

occlusive

Vehicle:

CMC (carboxymethyl cellulose)

Remarks:

1% Aqueous carboxymethyl cellulose

Details on dermal exposure:

One day before exposure (Day -1) an area of approximately 5x7 cm on the back of the animal was clipped.

The formulation was applied in an area of approx. 10% of the total body surface, i.e. approx. 25 cm² for males and 18 cm² for females. The formulation was held in contact with the skin with a dressing, consisting of a surgical gauze patch (Surgy 1D)*, successively covered with aluminum foil and Coban elastic bandage*. A piece of Micropore tape* was additionally used for fixation of the bandages in females only.
*. Manufacturers: Laboratoires Stella s.a., Liege, Belgium (surgical gauze) and 3M, St. Paul, Minnesota, U.S.A. (Coban & Micropore).

Frequency: Single dosage, on Day 1.

Washing: Following application, dressings were removed and the skin cleaned of residual test substance using tap water.

Duration of exposure:

24 hours

Doses:

2000 mg/kg (10 mL/kg) body weight.

No. of animals per sex per dose:

5

Control animals:

no

Details on study design:

VEHICLE
- Justification for choice of vehicle: The vehicle was selected based on trial formulations performed at NOTOX and on test substance data supplied by the sponsor.


DOSAGE PREPARATION: The formulation (w/w) was prepared within 4 hours prior to dosing. Homogeneity was accomplished to a visually acceptable level.

Duration of observation period following administration: 14 days
- Frequency of observations and weighing:
Mortality/Viability: Twice daily
Body weights: Days 1 (pre-administration), 8 and 15.
Clinical signs: At periodic intervals on the day of dosing (Day 1) and once daily thereafter, until Day 15. The symptoms were graded according to fixed scales and the time of onset, degree and duration were recorded.
- Necropsy of survivors performed: yes. At the end of the observation period, all animals were sacrificed by oxygen/carbon dioxide procedure and subjected to necropsy. Descriptions of all internal macroscopic abnormalities were recorded.
- Other examinations performed: none.

Statistics:

None

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

No mortality occurred.

Clinical signs:

other: Flat/hunched posture and ptosis were noted among a few animals between Days 1 and 2. Scales on the treated skin or right flank and chromodacryorrhoea were incidentally noted among most animals during the observation period.

Gross pathology:

No abnormalities were found at macroscopic post mortem examination of the animals .

Applicant's summary and conclusion

Interpretation of results:

study cannot be used for classification

Remarks:

Migrated information

Conclusions:

The dermal LD50 value of Silicic acid(H2Si2O5), barium salt(1:1), lead-doped in Wistar rats was established to exceed 2000 mg/kg body weight.

Based on these results, Silicic acid(H2Si2O5), barium salt(1:1), lead-doped does not have to be classified and has no obligatory labeling requirement for acute dermal toxicity according to the:
- Globally Harmonized System of Classification and Labeling of Chemicals (GHS) of the United Nations (2007),
- Regulation (EC) No 1272/2008 on classification, labeling and packaging of substances and mixtures.