2,4,8,10-tetraoxa-3λ6,9λ6-dithiaspiro[5.5]undecane 3,3,9,9-tetraoxide

Endpoint summary

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Endpoint:

skin corrosion: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 431 (In Vitro Skin Corrosion: Human Skin Model Test)

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Name: 2,4,8,10-Tetraoxa-3,9-dithiaspiro[5.5]undecane, 3,3,9,9-tetraoxide
CAS No.: 201419-80-9
Lot number: AZ08AVL1
Active component: ≥99% (Assay by GC: 99.9%)
Appearance: crystalline solid, white
Expiration date: 21 September 2021
Storage conditions: room temperature, protected from humidity, in a well-closed
container
Safety precautions: routine safety precautions (lab coat, gloves, safety masks, face mask,
goggles)

Test system:

human skin model

Source species:

other: EpiSkinTM Small Model (EpiSkinTMSM), EPISKIN Laboratories Lyon, France, is a threedimensional human epidermis model.

Cell type:

other: Adult human-derived epidermal keratinocytes are seeded on a dermal substitute consisting of a collagen type I matrix coated with type IV collagen.

Cell source:

other: Adult human-derived epidermal keratinocytes are seeded on a dermal substitute consisting of a collagen type I matrix coated with type IV collagen.

Source strain:

not specified

Details on animal used as source of test system:

not applicable

Justification for test system used:

The EPISKIN model has been validated for corrosivity testing in an international trial; it is
considered to be suitable for this study (STATEMENT ON THE SCIENTIFIC VALIDITY OF
THE EPISKINTM TEST (AN IN VITRO TEST FOR SKIN CORROSIVITY); ECVAM JRC
Environment Institute, European Commission; Ispra; 03 April 1998).

Vehicle:

unchanged (no vehicle)

Remarks:

The test item was applied in its original form, no formulation was required.

Details on test system:

A highly differentiated and stratified epidermis model is obtained after 13-day culture period
comprising the main basal, supra basal, spinous and granular layers and a functional stratum
corneum (Tinois et al., 1994). Its use for skin corrosion testing involves topical application of
test materials to the surface of the epidermis, and the subsequent assessment of their effects on
cell viability.

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

Test Item
An amount of 20 mg test item was applied evenly to the epidermal surface of the two test skin
units/exposure times respectively. Subsequently, 100 µL NaCl solution (9 g/L saline) was
added topically (to each unit) to ensure good contact with the epidermis. The test item was
spread gently with the pipette tip in order to cover evenly all the epidermal surface if necessary.

Duration of post-treatment incubation (if applicable):

The plates with the test item treated epidermis units were incubated for the exposure times of 4
hours (±10 min), 1 hour (±5 min) and 3 minutes at room temperature. Negative controls were
tested with each exposure time (4 h, 1 h, 3 min). The positive control was tested only for the
4 h exposure time. Temperature measured during the exposure (using a min/max thermometer)
was in the range of 23.7-24.2 °C.

Number of replicates:

In this assay 2 replicates of the test item (for each exposure time), 2 replicates of negative
control (for each exposure time) and 2 replicates of the positive control (for the 4 h exposure
only) were used.

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

4h

Value:

ca. 104

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

1h

Value:

ca. 102

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

3 min

Value:

ca. 107

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Other effects / acceptance of results:

Every test item treated tissue viability was above 35 % of the mean negative control value after 4 hours, 1 hour and 3 minutes exposure. The average test item treated tissue relative viabilities
were 104 % at 4 hours, 102 % at 1 hour and 107 % at 3 minutes of exposure.

Interpretation of results:

GHS criteria not met

Conclusions:

In conclusion, in this in vitro skin corrosion test in EPISKIN model (OECD 431) with
2,4,8,10-Tetraoxa-3,9-dithiaspiro[5.5]undecane, 3,3,9,9-tetraoxide the results indicate
that the test item is not corrosive to skin after 4 hours, 1 hour and 3 minutes of exposure
time. In conclusion, the test item 2,4,8,10-Tetraoxa-3,9-dithiaspiro[5.5]undecane, 3,3,9,9-
tetraoxide can be classified as Non-corrosive.


EpiSkinTMSM test of the test item 2,4,8,10-Tetraoxa-3,9-dithiaspiro[5.5]undecane, 3,3,9,9-
tetraoxide has been performed to predict its corrosion potential by measurement of its cytotoxic
effect, as reflected in the MTT assay according to the OECD Test Guideline No. 431, 18 June
2019.
Disks of EPISKIN (two units / test item / incubation time) were treated with the test item and
incubated for 4 hours (±10 min), 1 hour (±5 min) and 3 minutes at room temperature. Exposure
of test item was terminated by rinsing with 1x PBS solution. The viability of each disk was
assessed by incubating the tissues for 3 hours (±15 min) with MTT solution at 37±1 °C in an
incubator with 5±1 % CO2 in a ≥ 95 % humidified atmosphere and protected from light. The
formazan precipitated was then extracted using acidified isopropanol and quantified
spectrophotometrically.
NaCl (9 g/L saline) and glacial acetic acid treated epidermis were used as negative and positive
controls, respectively.
For each treated tissue viability was expressed as a % relative to negative control. The test item
is considered to be non-corrosive to skin, if the mean relative viability after 4 hours of exposure
is above or equal 35 % of the negative control.
Every test item treated tissue viability was above 35 % of the mean negative control value after
4 hours, 1 hour and 3 minutes exposure. The average test item treated tissue relative viabilities
were 104 % at 4 hours, 102 % at 1 hour and 107 % at 3 minutes of exposure.
Positive and negative controls showed the expected cell viability values within acceptable
limits.
All assay acceptance criteria were met, the experiment was considered to be valid.
In conclusion, in this in vitro skin corrosion test in EPISKIN model (OECD 431) with
2,4,8,10-Tetraoxa-3,9-dithiaspiro[5.5]undecane, 3,3,9,9-tetraoxide the results indicate
that the test item is not corrosive to skin after 4 hours, 1 hour and 3 minutes of exposure
time. In conclusion, the test item 2,4,8,10-Tetraoxa-3,9-dithiaspiro[5.5]undecane, 3,3,9,9-
tetraoxide can be classified as Non-corrosive.

Executive summary:

EpiSkinTMSM test of the test item 2,4,8,10-Tetraoxa-3,9-dithiaspiro[5.5]undecane, 3,3,9,9-
tetraoxide has been performed to predict its corrosion potential by measurement of its cytotoxic
effect, as reflected in the MTT assay according to the OECD Test Guideline No. 431, 18 June
2019.

Disks of EPISKIN (two units / test item / incubation time) were treated with the test item and
incubated for 4 hours (±10 min), 1 hour (±5 min) and 3 minutes at room temperature. Exposure
of test item was terminated by rinsing with 1x PBS solution. The viability of each disk was
assessed by incubating the tissues for 3 hours (±15 min) with MTT solution at 37±1 °C in an
incubator with 5±1 % CO2in a ≥ 95 % humidified atmosphere and protected from light. The
formazan precipitated was then extracted using acidified isopropanol and quantified
spectrophotometrically.
NaCl (9 g/L saline) and glacial acetic acid treated epidermis were used as negative and positive
controls, respectively.
For each treated tissue viability was expressed as a % relative to negative control. The test item
is considered to be non-corrosive to skin, if the mean relative viability after 4 hours of exposure
is above or equal 35 % of the negative control.
Every test item treated tissue viability was above 35 % of the mean negative control value after
4 hours, 1 hour and 3 minutes exposure. The average test item treated tissue relative viabilities
were 104 % at 4 hours, 102 % at 1 hour and 107 % at 3 minutes of exposure.
Positive and negative controls showed the expected cell viability values within acceptable
limits.
All assay acceptance criteria were met, the experiment was considered to be valid.
In conclusion, in thisin vitroskin corrosion test in EPISKIN model (OECD 431) with
2,4,8,10-Tetraoxa-3,9-dithiaspiro[5.5]undecane, 3,3,9,9-tetraoxide the results indicate
that the test item is not corrosive to skin after 4 hours, 1 hour and 3 minutes of exposure
time. In conclusion, the test item 2,4,8,10-Tetraoxa-3,9-dithiaspiro[5.5]undecane, 3,3,9,9-
tetraoxide can be classified as Non-corrosive.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Eye irritation

Link to relevant study records

Reference

Endpoint:

eye irritation: in vitro / ex vivo

Type of information:

(Q)SAR

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model and falling into its applicability domain, with adequate and reliable documentation / justification

Justification for type of information:

QSAR

Principles of method if other than guideline:

QSAR

GLP compliance:

no

Irritation parameter:

other:

Remarks on result:

positive indication of irritation

Interpretation of results:

Category 1 (irreversible effects on the eye) based on GHS criteria

Conclusions:

It is classifed as eye irritant category 1. H318

QSAR Computational tool: Topkat
The eye irritation/corrosion potential was estimated by using a battery of models, including ACD/Percepta,
Topkat and Toxtree. Following a detailed assessment of the generated QSAR predictions, the most reliable
prediction was provided by Topkat.
Topkat provides qualitative prediction (binary classification) for eye irritation potential, based on standard
rabbit Draize test data. For modelling purposes, the following classification was used: i) None Irritant:
maximum average score between 0 and 5; ii) Mild Irritant: maximum average score between 5 and 15; iii)
Moderate Irritant: maximum average score between 15 and 50; iv) Severe Irritant: maximum average Score
between 50 and 110. The models for eye irritation are comprised of three multiple stages: in the first stage,
non-irritants are separate from irritants (including mild, moderate or severe irritants); at the second stage,
mild irritants are separated from mild/severe irritants; at the third stage, moderate irritants are separated from
severe irritants.
The prediction results of eye irritation/corrosion potential for the target 2,4,8,10-Tetraoxa-3,9-
dithiaspiro[5.5]undecane, 3,3,9,9-tetraoxide is modearte irritant .
Reliability moderate

Executive summary:

It is moderate irritant.

It is classifed as eye irritant category 1. H318

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available