Sodium octane-1-sulphonate monohydrate

Endpoint summary

Description of key information

Skin corrosion, in vitro: Corrosive (Cat. 1B); OECD 431; Gehrke, H. (2018).

Eye irritation, in vitro; Eye Damage Cat. 1; OECD 437; Burkhardt, S. (2018).

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Reference 1

Endpoint:

skin irritation: in vivo

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

other:

Justification for type of information:

JUSTIFICATION FOR DATA WAIVING
As per Regulation (EC) 1907/2006, Annex VIII, Part 8.1, Column 2:
An in vivo study for skin corrosion/irritation shall be considered only if the in vitro studies under points 8.1.1 (skin corrosion in vitro) and 8.1.2 (skin corrosion in vivo) in Annex VII are not applicable, or the results of these studies are not adequate for classification and risk assessment.

Reference 2

Endpoint:

skin corrosion: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

18 April - 04 September 2017 (report amendment issued: 15 September 2017)

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

Study was conducted in accordance with international guidelines and in accordance with GLP. All guideline validity criteria were met.

Qualifier:

according to guideline

Guideline:

OECD Guideline 431 (In Vitro Skin Corrosion: Reconstructed Human Epidermis (RHE) Test Method)

Version / remarks:

29 July 2009

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: EU Method B.40 BIS: In Vitro Skin Corrosion: Human Skin Model Test

Version / remarks:

Council Regulation (EC) No 440/2008, 30 May 2008

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

RADIOLABELLING INFORMATION (if applicable)
- Radiochemical purity: n/a
- Specific activity: n/a
- Locations of the label: n/a
- Expiration date of radiochemical substance: n/a

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: room temperature
- Stability under test conditions: assumed stable
- Solubility and stability of the test substance in the solvent/vehicle: test item applied as a paste using 50 µL water per 25 mg of test item powder.
- Reactivity of the test substance with the solvent/vehicle of the cell culture medium: no

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing: test item applied as a paste using 50 µL water per 25 mg of test item powder.
- Preliminary purification step (if any): no
- Final dilution of a dissolved solid, stock liquid or gel: 25 mg of test item applied to skin using 50 µL of water (as a paste)
- Final preparation of a solid: n/a

FORM AS APPLIED IN THE TEST (if different from that of starting material) : test item applied as a paste using 50 µL water per 25 mg of test item powder.

TYPE OF BIOCIDE/PESTICIDE FORMULATION (if applicable) n/a

OTHER SPECIFICS: n/a

Test system:

human skin model

Source species:

human

Cell type:

non-transformed keratinocytes

Cell source:

other: normal (non-cancerous), human-derived epidermal keratinocytes (NHEK) were cultured to form a multilayered, highly differentiated model of the human epidermis. Model was supplied by MatTek In Vitro Life Sciences, Bratislava, Slovak Republic

Details on test system:

RECONSTRUCTED HUMAN EPIDERMIS (RHE) TISSUE
- Model used: EpiDermTM Reconstructed Human Epidermis
- EpiDerm RHE kit lot #: 25806
- Production date: Not reported
- Shipping date: Not reported
- Delivery date: Not reported
- Date of initiation of testing: 20 April 2017

TEMPERATURE USED FOR TEST SYSTEM
- Temperature used during treatment / exposure: 37 ± 1 ºC
- Temperature of post-treatment incubation (if applicable): 37 ± 1 ºC

REMOVAL OF TEST MATERIAL AND CONTROLS
-Volume and number of washing steps: Rinsed with PBS ("20 times"), volume not reported.
- Observable damage in the tissue due to washing: Not reported, assume no.
- Modifications to validated SOP: No

MTT DYE USED TO MEASURE TISSUE VIABILITY AFTER TREATMENT / EXPOSURE
- MTT concentration: 1 mg/mL
- Incubation time: 3 hours
- Spectrophotometer: Yes, details not reported
- Wavelength: 570 nm
- Filter: No / not reported
- Filter bandwidth: No / not reported
- Linear OD range of spectrophotometer: Not reported

FUNCTIONAL MODEL CONDITIONS WITH REFERENCE TO HISTORICAL DATA
- Viability: Acceptable
- Barrier function: Not reported
- Morphology: Not reported
- Contamination: Not reported
- Reproducibility: COV of mean replicated was <30 %.

NUMBER OF REPLICATE TISSUES: 2

CONTROL TISSUES USED IN CASE OF MTT DIRECT INTERFERENCE
- Freeze killed tissues
- Procedure used to prepare the killed tissues (if applicable): Not applicable - substance was not a MTT reducer.
- No. of replicates : Not applicable

NUMBER OF INDEPENDENT TEST SEQUENCES / EXPERIMENTS TO DERIVE FINAL PREDICTION: 2

PREDICTION MODEL / DECISION CRITERIA (choose relevant statement)
- The test substance is considered to be corrosive to skin if the viability after 3 minutes exposure is less than 50%, or if the viability after 3 minutes exposure is greater than or equal to 50 % and the viability after 1 hour exposure is less than 15%.
- The test substance is considered to be non-corrosive to skin if the viability after 3 minutes exposure is greater than or equal to 50% and the viability after 1 hour exposure is greater than or equal to 15%.
- Justification for the selection of the cut-off point(s) if different than recommended in TG 431 and 439: N/a

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 25 mg
- Concentration (if solution): Powder applied using 50 µL of distilled water (as a paste)

VEHICLE
- Amount(s) applied (volume or weight with unit): 50 µL
- Concentration (if solution): Not applicable
- Lot/batch no. (if required): Lot # RNBF7110
- Purity: Not reported (assume 100 % for distilled water)

NEGATIVE CONTROL
- Amount(s) applied (volume or weight): 50 µL
- Concentration (if solution): Not applicable

POSITIVE CONTROL
- Amount(s) applied (volume or weight): 50 µL
- Concentration (if solution): 8 N

Duration of treatment / exposure:

3 minutes and 60 minutes

Duration of post-treatment incubation (if applicable):

Incubated in MTT medium for 3 hours and followed by an overnight extraction in isopropanol.

Number of replicates:

2 for each treatment

Species:

other: n/a

Strain:

other: n/a

Details on test animals or test system and environmental conditions:

n/a

Type of coverage:

other: n/a

Preparation of test site:

other: n/a

Vehicle:

other: n/a

Amount / concentration applied:

n/a

Duration of treatment / exposure:

n/a

Observation period:

n/a

Number of animals:

n/a

Details on study design:

n/a

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

3 min exposure

Value:

87.9

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

no indication of irritation

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

60 min exposure

Value:

4.2

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

positive indication of irritation

Other effects / acceptance of results:

- OTHER EFFECTS:
- Visible damage on test system: No
- Direct-MTT reduction: No
- Colour interference with MTT: No

DEMONSTRATION OF TECHNICAL PROFICIENCY: Yes

ACCEPTANCE OF RESULTS:
- Acceptance criteria met for negative control: Yes
- Acceptance criteria met for positive control: Yes
- Acceptance criteria met for variability between replicate measurements: Yes
- Range of historical values if different from the ones specified in the test guideline: N/A

Table 2:       Mean OD₅₇₀Values and Viabilities for the Negative Control Item, Positive Control Item and Test Item

Tissue	Exposure Period	MeanOD570of individual tissues	Mean OD570of duplicate tissues	Standard Deviation	Coefficient of Variation (%)***	Relative Mean Viability (%)
Negative Control	3 Minutes	1.646	1.663*	0.025	1.5	100
		1.681
	60 Minutes	1.680	1.695*	0.020	1.2
		1.709
Positive Control	3 Minutes	0.144	0.148	0.005	3.1	8.9
		0.151
	60 Minutes	0.075	0.097	0.032	32.8	5.7**
		0.120
Test Item	3 Minutes	1.482	1.462	0.029	2.0	87.9
		1.442
	60 Minutes	0.077	0.071	0.020	1.2	4.2
		0.066

* mean OD₅₇₀0.7 – 2.8

** mean relative tissue viability of the 60 min positive control < 15 %

*** COV (in the range of 20 – 100 % viability) between two tissues treated identically is ≤ 30 %

Interpretation of results:

Category 1B (corrosive) based on GHS criteria

Conclusions:

In this study under the given conditions the test item showed corrosive effects. The mean relative tissue viability (% negative control) was reduced below 15% after 60 min treatment but not below 50% after 3 min treatment. Sodium Octane-1-sulphonate is therefore classified as “corrosive“ in accordance with UN GHS sub-category 1B.

Executive summary:

OECD 431 (2017) - The skin corrosivity potential of sodium octane-1-sulphonate was assessed using an EpiDerm Reconstructed Human Epidermis (RHE) Model Kit in accordance with OECD guidance 431 and GLP.

Duplicate tissues were treated with the test item for exposure periods of 3 and 60 mins. At the end of the exposure period the test item was rinsed from each tissue before being loaded with MTT. After MTT loading each tissue was placed in 2 mL isopropanol for MTT extraction. After extraction, each tissue was pierced and the extraction solution aliquoted for absorbance measurements. Absorbency at 570 nm of each well was measured using a spectrophotometer.

Mean viability of tissues exposed to the test substance after 3 and 60 minutes were 87.9 % and 4.2 %, respectively. The quality criteria required for acceptance of the results was met.

Under the conditions of this study the test substance is considered to be corrosive to the skin in accordance with a combination of optional UN GHS sub-categories 1B and 1C; however for the purposes of conservative classification the substances is designated as corrosive: sub-category 1B.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (corrosive)

Eye irritation

Link to relevant study records

Reference

Reference 1

Endpoint:

eye irritation: in vivo

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

other:

Justification for type of information:

JUSTIFICATION FOR DATA WAIVING
As per Regulation (EC) 1907/2006, Annex VIII, Part 8.2, Column 2:
An in vivo study for eye corrosion/irritation shall be considered only if the in vitro studies under points 8.2.1 (serious eye damage/eye irritation, in vitro) in Annex VII are not applicable, or the results of these studies are not adequate for classification and risk assessment.
Additionally, Part 8.2, Column 2 goes on to state that:
The study does not need to be conducted if: the substance is classified as skin corrosion, leading to classification as serious eye damage (Category 1).

Reference 2

Endpoint:

eye irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

10 May 2017 - 15 January 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

Study conducted in accordance with International guidelines and GLP. All guideline validity criteria were met.

Qualifier:

according to guideline

Guideline:

OECD Guideline 437 (Bovine Corneal Opacity and Permeability Test Method for Identifying i) Chemicals Inducing Serious Eye Damage and ii) Chemicals Not Requiring Classification for Eye Irritation or Serious Eye Damage)

Version / remarks:

26 July 2013

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU method B.47 (Bovine corneal opacity and permeability test method for identifying ocular corrosives and severe irritants)

Version / remarks:

Council Regulation (EC) No. 440/2008, 30 May 2008

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

RADIOLABELLING INFORMATION (if applicable)
- Radiochemical purity: N/A
- Specific activity: N/A
- Locations of the label: N/A
- Expiration date of radiochemical substance: N/A

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Room temperature
- Stability under test conditions: Assumed stable
- Solubility and stability of the test substance in the solvent/vehicle: Suspended and assumed stable.
- Reactivity of the test substance with the solvent/vehicle of the cell culture medium: Not reported

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing: Test item was suspended with physiological saline (0.9 % NaCl) to give a 20 % concentration w/w.
- Preliminary purification step (if any): N/A
- Final dilution of a dissolved solid, stock liquid or gel: 20 % solution w/w
- Final preparation of a solid: N/A

FORM AS APPLIED IN THE TEST (if different from that of starting material) : Applied as a liquid

TYPE OF BIOCIDE/PESTICIDE FORMULATION (if applicable) : N/A

OTHER SPECIFICS: N/A

Species:

cattle

Strain:

not specified

Details on test animals or tissues and environmental conditions:

SOURCE OF COLLECTED EYES
- Source: A. Moksel AG, Buchloe, Germany - abattoir
- Number of animals: Not reported
- Characteristics of donor animals (e.g. age, sex, weight): Cattle aged between 16 - 45 months
- Storage, temperature and transport conditions of ocular tissue (e.g. transport time, transport media and temperature, and other conditions): The eyes were removed after slaughter, completely immersed in Hanks’ Balanced Salt Solution (containing penicillin and streptomycin (1 % v/v)) in a container on ice and transported on the same day to the testing facility.
- Time interval prior to initiating testing: Same day as slaughter
- indication of any existing defects or lesions in ocular tissue samples: Only corneas free of defects were used.
- Indication of any antibiotics used: Penicillin and streptomycin used to transport eyes to testing facility.

Vehicle:

physiological saline

Remarks:

B. Braun Melsungen, Batch # 17031412, Expiry 26 May 2017

Controls:

yes, concurrent vehicle

yes, concurrent positive control

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 750 µL
- Concentration (if solution): 20 %

VEHICLE
- Amount(s) applied (volume or weight with unit): 750 µL
- Concentration (if solution): 0.9 % NaCl
- Lot/batch no. (if required): 17031412
- Purity: Not reported

Duration of treatment / exposure:

4 hours ± 5 mins

Observation period (in vivo):

N/A

Duration of post- treatment incubation (in vitro):

After the exposure period, the corneas were rinsed with minimum essential medium with phenol red (MEM) and RPMI 1640 without phenol red (RPMI) (once the corneas were free of test item). Corneas were then incubated in RPMI and illuminance measurements recorded. Corneas were then incubated in fresh RPMI containing 1 mL of a 5 mg/mL sodium flurescein solution for 90 minutes.

Number of animals or in vitro replicates:

3 corneas per treatment group

Details on study design:

SELECTION AND PREPARATION OF CORNEAS: On arrival at the test facility the eyes were carefully examined for defects. Only corneas free from such defects were used.

QUALITY CHECK OF THE ISOLATED CORNEAS: The opacity of each cornea was measured using an opacitometer. Three corneas with illuminance readings approximately equivalent to the median illuminance of all corneas were selected as negative controls. Only corneas with an initial illuminance reading of I > I0 / 1.1651 lux were used for the assay.

NUMBER OF REPLICATES: 3 per treatment group.

NEGATIVE CONTROL USED: Vehicle control used below.

SOLVENT CONTROL USED (if applicable): The vehicle control substance was 0.9% sodium chloride solution.

POSITIVE CONTROL USED: The positive control substance was a 20 % solution of imidazole in 0.9 % NaCl.

APPLICATION DOSE AND EXPOSURE TIME: 4 hours ± 5 mins

TREATMENT METHOD:

After recording the initial illuminance measurements , 750 µL of the test item solution or control solution was incubated with each prepared cornea for 4 hours (± 5 mins) at 32 ± 1 ºC. The test item (or control solution) was rinsed from the cornea using MEM. Once free of test item, the cornea was rinsed and incubated with RPMI - a second illuminance reading was then taken along with a viaual inspection of the cornea condition. After the initial reading, the cornea was incubated with fresh RPMI containing 1 mL of a 5 mg/mL sodium fluoroscein solution for 90 mins at 31 ± 1 ºC. After 90 mins the solution was removed and the optical density measured using a spectrophotometer at 490 nm wavelength.

POST-INCUBATION PERIOD:
- See above

REMOVAL OF TEST SUBSTANCE
- See above

POST-EXPOSURE INCUBATION
- See above


METHODS FOR MEASURED ENDPOINTS:
- Corneal opacity: Opaciometer.
- Corneal permeability: Passage of sodium fluorescein dye measured with the aid of spectrophotometry (OD 490).
- Others (e.g, pertinent visual observations, histopathology): (please specify) Pertinent visual inspection of cornea

SCORING SYSTEM: In Vitro Irritancy Score (IVIS)

DECISION CRITERIA: please specify if the decision criteria as indicated in the TG was used. As per OECD 437.

Irritation parameter:

in vitro irritation score

Value:

208.5

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

positive indication of irritation

Other effects / acceptance of results:

OTHER EFFECTS:
- Visible damage on test system: All test item cornea showed complete opacity of the tissue and whiteish discolouration of the corneas.

DEMONSTRATION OF TECHNICAL PROFICIENCY: Yes, IVIS score for the negative and positive controls fell within 2 standard deviations of the laboratries current historical mean (n=23)

ACCEPTANCE OF RESULTS:
- Acceptance criteria met for negative control: Yes
- Acceptance criteria met for positive control: Yes
- Range of historical values if different from the ones specified in the test guideline: See above

Table 2:       Opacity

 

Cornea No.	Test Group	Initial Opacity	Final Opacity	Change of Opacity	Corrected Opacity
1	Negative Control	1.42	1.38	-0.04	N/A
2		1.64	1.78	0.15
3		1.42	2.77	1.35
Mean		1.49	1.98	0.49
SD		0.13	0.72	0.76
4	Positive Control	2.27	79.48	77.21	76.72
5		2.01	85.31	83.31	82.82
6		2.35	91.75	89.40	88.91
Mean		2.21	85.51	83.30	82.82
SD		0.18	6.13	6.09	6.09
7	Test Item	0.11	174.49	174.38	173.89
8		0.01	157.90	157.89	157.40
9		0.70	166.78	166.08	165.59
Mean		0.27	166.39	166.12	165.63
SD		0.37	8.31	8.25	8.25

 

Table 3:       Permeability

 

Cornea No.	Test Group	OD490	Corrected OD490Value
1	Negative Control	0.006	N/A
2		0.015
3		0.015
Mean		0.012
SD		0.005
4	Positive Control	0.963	0.951
5		0.944	0.932
6		1.106	1.094
Mean		1.004	0.992
SD		0.089	0.089
7	Test Item	2.355	2.343
8		2.860	2.848
9		3.395	3.383
Mean		2.870	2.858
SD		0.520	0.520

 

Table 4:       In Vitro Irritation Score (IVIS)

 

Cornea No.	Test Group	Corrected Opacity	Corrected OD490	IVIS
1	Negative Control	-0.04	0.006	0.67
2		0.15	0.015
3		1.35	0.015
Mean		0.49	0.012
SD		0.76	0.005
4	Positive Control	76.72	0.951	97.70
5		82.82	0.932
6		88.91	1.094
Mean		82.82	0.992
SD		6.09	0.089
7	Test Item	173.89	2.343	208.50
8		157.40	2.848
9		165.59	3.383
Mean		165.63	2.858
SD		8.25	0.520

 

Interpretation of results:

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

Conclusions:

Under the condition of this study, the test item, produced an IVIS score of 208.50 and therefore has the potential to induce serious eye damage. Sodium octane-1-sulphonate can be classified as UN GHS Category 1.

Executive summary:

OECD 437 (2017) - The Bovine Corneal Opacity and Permeability (BCOP) test was conducted using sodium octane 1-sulphonate in accordance with OECD Guideline 437 "Bovine Corneal Opacity and Permeability Test Method for Identifying i) Chemicals Inducing Serious Eye Damage and ii) Chemicals Not Requiring Classification for Eye Irritation or Serious Eye Damage" (2013).

 

Test item was dissolved in physiological saline (0.9 % NaCl) to form a 20 % solution concentration. Triplicate corneas had their opacity measured and were incubated in the test solution for 4 hours ± 5 mins before being rinsed with minimal essential medium (with phenol red). After being further rinsed with RPMI (without phenol red) the opacity of each cornea was again measured. The permeability of the corneas was determined by measuring RPMI solution containing sodium fluorescein that has passed through the cornea membrane, after being suspended for 90 mins in a horizontal position, using a spectrophotometer. A negative and positive control group, each containing 3 corneas, were also prepared and treated using the same methodology.

 

For the test item, each of the treated corneas showed complete opacity of the tissue and whitish discolouration of the corneas. The negative and positive control values were in concordance with historical values and all guideline validity criteria were satisfied.

 

Under the conditions of this study, and with an IVIS score of 208.5, sodium octane-1-sulphonate showed the potential to induce serious eye damage. According to the guideline evaluation criteria, the test item is classified as UN GHS Category 1 for serious eye damage/ eye irritation.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irreversible damage)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Skin corrosion

OECD 431 (2017) - The skin corrosivity potential of sodium octane-1-sulphonate was assessed using an EpiDerm Reconstructed Human Epidermis (RHE) Model Kit in accordance with OECD Guidance 431 and GLP.

Duplicate tissues were treated with the test item for exposure periods of 3 and 60 mins. At the end of the exposure period the test item was rinsed from each tissue before being loaded with MTT. After MTT loading each tissue was placed in 2 mL isopropanol for MTT extraction. After extraction, each tissue was pierced and the extraction solution aliquoted for absorbance measurements. Absorbency at 570 nm of each well was measured using a spectrophotometer.

Mean viability of tissues exposed to the test substance after 3 and 60 minutes were 87.9 % and 4.2 %, respectively. The quality criteria required for acceptance of the results was met.

Under the conditions of this study the test substance is considered to be corrosive to the skin in accordance with a combination of optional UN GHS sub-categories 1B and 1C; however for the purposes of conservative classification the substance is designated as corrosive: sub-category 1B.

Eye irritation

OECD 437 (2017) - The Bovine Corneal Opacity and Permeability (BCOP) test was conducted using sodium octane 1-sulphonate in accordance with OECD Guideline 437 "Bovine Corneal Opacity and Permeability Test Method for Identifying i) Chemicals Inducing Serious Eye Damage and ii) Chemicals Not Requiring Classification for Eye Irritation or Serious Eye Damage" (2013).

Test item was dissolved in physiological saline (0.9 % NaCl) to form a 20 % solution concentration. Triplicate corneas had their opacity measured and were incubated in the test solution for 4 hours ± 5 mins before being rinsed with minimal essential medium (with phenol red). After being further rinsed with RPMI (without phenol red) the opacity of each cornea was again measured. The permeability of the corneas was determined by measuring RPMI solution containing sodium fluorescein that has passed through the cornea membrane, after being suspended for 90 mins in a horizontal position, using a spectrophotometer. A negative and positive control group, each containing 3 corneas, were also prepared and treated using the same methodology.

For the test item, each of the treated corneas showed complete opacity of the tissue and whitish discolouration of the corneas. The negative and positive control values were in concordance with historical values and all guideline validity criteria were satisfied.

Under the conditions of this study, and with an IVIS score of 208.5, sodium octane-1-sulphonate showed the potential to induce serious eye damage. According to the guideline evaluation criteria, the test item is classified as UN GHS Category 1 for serious eye damage/eye irritation.

Justification for classification or non-classification

Following the study compliant with OECD Test 437, the test item is classified as UN GHS Category 1 for serious eye damage resulting from an IVIS score of 208.5.

Results from an OECD 431 Test demonstrated that the mean relative tissue viability (% negative control) was reduced below 15% after 60 min treatment but not below 50% after 3 min treatment. The results obtained indicate that the substance is classified as corrosive to the skin with a combination of optional UN GHS sub-categories 1B and 1C, however for the purposes of conservative classification, the test item is classified as corrosive in accordance with UN GHS sub-category 1B.