Iodine

Endpoint summary

Description of key information

Skin irritation / corrosion:

Three in vitro skin irritation / corrosion studies are available. Of which two independent in vitro skin corrosion studies (OECD 435) give negative results. And the in vitro skin irritation (B.46) test gives positive result.

In addition, the human data available for skin irritation indicates that iodine can be irritant to normal skin in pet. and in 70% IPA.

 

Eye irritation:

An BCOP test (OECD 437) is available. IVIS was calculated to be 43539.36. As the intrinsic color of the test item could not be removed from the cornea after the 4 hour incubation, the result of this study must be seen with reservations. It is possible that the IVIS value is wrongly too high and the opacity could not be determined correctly, because of the intrinsic color of the test item that could not be removed from the cornea. Therefore no conclusive result could be achieved within this study.

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Reference 1

Endpoint:

skin corrosion: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Guideline study not following GLPs

Qualifier:

according to guideline

Guideline:

OECD Guideline 435 (In Vitro Membrane Barrier Test Method for Skin Corrosion)

Deviations:

no

GLP compliance:

no

Test system:

artificial membrane barrier model

Justification for test system used:

The Corrositex test is a standardized and reproducible method that can be employed to determine the potential corrosivity and the Packing Group classification of specified categories of chemical compounds under the hazardous materials transportation regulations administered by the U.S. Department of Transportation (DOT) and international dangerous goods codes. The Corrositex test predicts the in vivo corrosive potential of a chemical compound or mixture by using as an endpoint the amount of time it takes for a chemical to permeate through or destroy a synthetic biobarrier. A color change in a proprietary liquid Chemical Detection System (CDS) is used to indicate that the chemical has passed through the biobarrier.

Vehicle:

unchanged (no vehicle)

Details on test system:

The corrositex assay is a three step procedure. First, the sample is qualified to ensure that the test sample is compatible with the Corrositex system, then it is categorized according to pH, and finally it is classify based on the time the sample takes to break through the biobarrier.
Qualify: An aliquot of the sample was aded to the Chemical Detection System (CDS) reagent, and the vial was observed for any notable colour change. An observable colour change indicates that the test sample is compatible with the Corrositex system.
Categorize: The sample was categorized which determined cut-off times for the classification designation. A 10% aqueous solution of the sample was prepared, and the pH was measured. Based on the pH of a 10% solution, an aliquot was added to a respective Indicator Tube, based on the final pH of the Indicator Tube, a category was assigned to the sample (alternative method).
Classify: 500 mg of undiluted sample was added to 4 test vials containing biobarriers. A positive control was performed using 1.0 N sodium hydroxide. A negative control was also performed. The amount of time required for the test material to destroy the biobarrier was recorded and used to designate the classification.

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

TEST MATERIAL
- Amount applied: 500 mg of undiluted sample.
VEHICLE
- Amount applied: No vehicle was used.

Number of replicates:

4 for test item, one negative and one positive control

Irritation / corrosion parameter:

penetration time (in minutes)

Value:

> 65

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

other: Non-corrosive

The results indicated that the test sample was compatible with the Corrositex assay. The sample was categorized in Category 2 (table 1)

Table 1: Summary of results of qualification and categorization step

Concentration tested:	100%
pH taken from 10% aqueous solution	4.83
Colour in tube A/B	None
pH taken from tube A/B	7.03/6.65
Category	2

The penetration time and results are presented in Table 2.

Table 2: Penetration time and results.

Corrositex time (minutes)
Replicate #1	> 65
Replicate #2	> 65
Replicate #3	> 65
Replicate #4	> 65
Mean	> 65
Positive control #1	17
Positive control #2	16
Classification	Non-corrosive

Interpretation of results:

other: Non-Corrosive

Remarks:

Criteria used for interpretation of results: other: Dir. 67/548/EC, GHS and UN Packing Group Classification

Conclusions:

The findings of the study lead to the designation of the sample as a non-corrosive substance

Executive summary:

The test item was analyzed by the Corrositex test method to determine its corrosive potential and its classification.

The Corrositex test predicts the in vivo corrosive potential of a chemical compound or mixture by using as an endpoint the amount of time it takes for a chemical to permeate through or destroy a synthetic biobarrier. A color change in a proprietary liquid Chemical Detection System is used to indicate that the chemical has passed through the biobarrier.

The results of this study indicated that the sample was compatible with the Corrositex system and was determined to be a Category 2 sample. The results obtained from the evaluation of four replicates samples were consistent (> 65 minutes), demonstrating that a mean time of > 65 minutes was required to destroy the synthetic biobarriers. These findings lead to the classification of test item, as a Non-Corrosive material.

Reference 2

Endpoint:

skin corrosion: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Guideline Study not following GLPs - No information on positive and negative controls are reported.

Qualifier:

according to guideline

Guideline:

OECD Guideline 435 (In Vitro Membrane Barrier Test Method for Skin Corrosion)

Deviations:

not specified

GLP compliance:

not specified

Test system:

artificial membrane barrier model

Justification for test system used:

The Corrositex test is a standardized and reproducible method that can be employed to determine the potential corrosivity and determine the Packing Group classification of specified categories of chemical compounds under the hazardous materials transportation regulations administered by the U.S. Department of Transportation (DOT) and international dangerous goods codes. On June 22nd, 1999 the National Institute of Environmental Health Sciences (NIEHS), the National Toxicology Program and other federal agencies ( Including FDA, CPSC, OSHA, and EPA, etc.) that support the Interagency Coordinating Committee on the Validation of Alternative Methods (ICCV AM) announced their endorsement of the Corrositex test method. The Corrositex test predicts the in vivo corrosive potential of a chemical compound or mixture by using as an endpoint the time it takes for the chemical to permeate through or destroy a synthetic biobarrier. When the chemical has passed through this biobarrier, a visual change is produced in a proprietary Chemical Detection System (CDS).

Vehicle:

unchanged (no vehicle)

Details on test system:

The corrositex assay is a three step procedure. First, the sample is qualified to ensure that the test sample is compatible with the Corrositex system, then it is categorized according to pH, and finally it is classify based on the time the sample takes to break through the biobarrier.
Qualify: An aliquot of the sample was aded to the Chemical Detection System (CDS) reagent, and the vial was observed for any notable colour change. An observable colour change indicates that the test sample is compatible with the Corrositex system.
Categorize: The sample was categorized which determined cut-off times for the classification designation. An aqueous solution of the sample was prepared, and the pH was measured. Based on the pH of the solution, an aliquot was added to a respective Indicator Tube, based on the final pH of the Indicator Tube, a category was assigned to the sample (alternative method).
Classify: Undiluted sample was added to 4 test vials containing biobarriers.The amount of time required for the test material to destroy the biobarrier was recorded and used to designate the classification.

Control samples:

other: Not applicable

Amount/concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit):
No indicated in test report, but according to Corrositex protocol approximately 500 mg should be applied

Duration of treatment / exposure:

In the corrositex, the time required for the test material to destroy the biobarrier is recorded.

Number of replicates:

4

Details on study design:

See below

Irritation / corrosion parameter:

penetration time (in minutes)

Value:

> 60

Remarks on result:

other: non-corrosive

Test results summary:

Conc. tested	Neat
pH (10% aqueous solution)	6.60
Category	2
Replicate #1	> 60 minutes
Replicate #2	> 60 minutes
Replicate #3	> 60 minutes
Replicate #4	> 60 minutes
Mean ± SD	> 60 minutes
Packing group	Non-corrosive

Interpretation of results:

other: Non-corrosive

Remarks:

Criteria used for interpretation of results: other: Dir. 67/548/EC, GHS and UN Packing Group Classification

Conclusions:

The findings of the study lead to the designation of the sample as a non-corrosive substance

Executive summary:

The test sample was evaluated with the Corrositex test method to determine its corrosive potential an to designate its Packing Group classification.

The Corrositex test predicts the in vivo corrosive potential of a chemical compound or mixture by using as an endpoint the amount of time it takes for a chemical to permeate through or destroy a synthetic biobarrier. A color change in a proprietary liquid Chemical Detection System is used to indicate that the chemical has passed through the biobarrier.

The results of this study indicated that the sample was compatible with the Corrositex system and was determined to be a Category 2 sample. The results obtained from the evaluation of four replicates samples were consistent (> 60 minutes), demonstrating that a mean time of > 60 minutes was required to destroy the synthetic biobarriers. These findings lead to the classification of test item as a Non-Corrosive material.

Reference 3

Endpoint:

skin irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From 2010-02-22 to 2010-03-01

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method B.46 (In Vitro Skin Irritation: Reconstructed Human Epidermis Model Test)

Version / remarks:

Amended by EC No. 761/2009 OJ No. L220, 24 August 2009.

Deviations:

no

GLP compliance:

yes

Test system:

human skin model

Source species:

human

Cell type:

non-transformed keratinocytes

Details on test system:

RECONSTRUCTED HUMAN EPIDERMIS (RHE) TISSUE
- Model used: EPISKIN Standard Model
- Tissue batch number(s): 10-EKIN-006

TEMPERATURE USED FOR TEST SYSTEM
- Temperature used during treatment / exposure: 22 ℃
- Temperature of post-treatment incubation (if applicable): 37℃

REMOVAL OF TEST MATERIAL AND CONTROLS
-Volume and number of washing steps: the tissues were washed with phosphate buffered saline to remove residual test substance. After rinsing the cell culture inserts were each dried carefully.

MTT DYE USED TO MEASURE TISSUE VIABILITY AFTER TREATMENT / EXPOSURE
- MTT concentration: 0.3 mg/mL
- Incubation time: 3 h at 37℃
- Spectrophotometer: Multiskan Spectrum (Thermo Labsystems).
- Wavelength: 570 nm

NUMBER OF REPLICATE TISSUES: three

NUMBER OF INDEPENDENT TEST SEQUENCES / EXPERIMENTS TO DERIVE FINAL PREDICTION: 1

PREDICTION MODEL / DECISION CRITERIA
- A test substance is considered irritant in the skin irritation test if:
The relative mean tissue viability of three individual tissues after 15 minutes of exposure to the test substance and 42 hours of post incubation is ≤ 50% of the mean viability of the negative controls.
- A test substance is considered non-irritant in the in vitro skin irritation test if:
The relative mean tissue viability of three individual tissues after 15 minutes of exposure to the test substance and 42 hours of post incubation is > 50% of the mean viability of the negative controls.

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 10 mg

NEGATIVE CONTROL
- Amount(s) applied (volume or weight): 10 μL

POSITIVE CONTROL
- Amount(s) applied (volume or weight): 10 μL
- Concentration (if solution): 5%

Duration of treatment / exposure:

15 minutes

Duration of post-treatment incubation (if applicable):

42 hours

Number of replicates:

3

Irritation / corrosion parameter:

% tissue viability

Value:

11

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

other: Time point: 15 min exposure

Other effects / acceptance of results:

The test item was checked for possible direct MTT reduction by adding the test substance to MTT medium. Because no colour change was observed it was concluded that lodine did not interact with MTT.
The positive control had a mean cell viability after 15 minutes exposure of 22%. The absolute mean OD570 of the negative control tissues was within the laboratory historical control data range. The standard deviation value of the percentage viability of three tissues treated identically was less than 18%, indicating that the test system functioned properly.

Cell Viability Measurement

The mean absorption at 570 nm measured after treatment with Iodine and controls are presented in Table 1.

Table 1: Mean absorption in the in vitro skin irritation test with Iodine

	A(OD 570)	B(OD570)	C(OD570)	Mean ± SD
Negative control	0.792	0.825	0.794	0.804 ± 0.018
Iodine	0.078	0.097	0.091	0.089 ± 0.010
Positive control	0.175	0.170	0.176	0.173 ± 0.003

OD= Optical density

SD= Standard deviation

Triplicate exposures are indicated by A, B and C.

Table 2 shows the mean tissue viability obtained after 15 minutes treatment with Iodine compared to the negative control tissues. Skin irritation is expressed as the remaining cell viability after exposure to the test substance. The relative mean tissue viability obtained after 15 minutes treatment with Iodine compared to the negative control tissues was 11%. Since the mean relative tissue viability for iodine was below 50% it is considered to be an irritant.

Table 2: Mean tissue viability in the in vitro skin irritation test with Iodine

	Mean tissue viability (percentage of control)
Negative control	100
Iodine	11
Positive control	22

Interpretation of results:

other: irritating

Conclusions:

The test item is irritant in the in vitro skin irritation test under the experimental conditions described.

Executive summary:

The test item was tested to evaluate its ability to induce skin irritation on a human three dimensional epidermal model (EPISKIN Standard Model). The procedure followed most recent OECD and EC Guidelines.

At least 10 mg of crushed and ground test substance was applied directly on top of the skin tissue. After a 42 hour incubation period, determination of the cytotoxic (irritancy) effect was performed. Cytotoxicity is expressed as the reduction of mitochondrial dehydrogenase activity measures by formazan production from MTT at the end of the treatment.

Skin irritation is expressed as the remaining cell viability after exposure to the test substance. The relative mean tissue viability obtained after 15 minutes treatment with Test item compared to the negative control tissues was 11%. Since the mean relative tissue viability for test item was below 50% after 15 minutes treatment it is considered to be irritant.

The positive control had a mean cell viability after 15 minutes exposure of 22%. The absolute mean optical density at 570 nm of the negative control tissues was within the laboratory historical control data range.

It is concluded that this test is valid and that the test item is irritant in the in vitro skin irritation test under the experimental conditions described in this assay.

Reference 4

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

no guideline followed

Principles of method if other than guideline:

This study examines the irritant potential and threshold of iodine in 3 different preparations, namely petrolatum (pet.), 70% isopropyl alcohol (IPA) and PVP-I with different concentrations in normal healthy subjects without iodine allergy, in order to refine appropriate non-irritant diagnostic patch-test concentrations.

GLP compliance:

not specified

Specific details on test material used for the study:

- Purity: 99.99%
- Source: Fisher Scientific (Pittsburgh, PA, USA)

Species:

other: Human

Details on test animals or test system and environmental conditions:

24 fair-skinned subjects (6 men, 18 women; aged 18–65, mean 47), in good health and with no history of allergies or significant skin disease, were recruited to participate in this study.

Type of coverage:

other: closed patch tests

Vehicle:

other: petrolatum (pet.), 70% isopropyl alcohol (IPA) and PVP-I

Controls:

yes

Amount / concentration applied:

Concentrations of 0.5%, 1%, 5% and 10% iodine in pet., 0.5%, 0.75% and 1% iodine in 70% IPA and 1%, 5%, 7.5% and 10% of PVP-I were applied to the intrascapular area on the back or to the volar forearm between cubital fossa and wrist as per participants’ wish.

Duration of treatment / exposure:

2 days

Observation period:

4 days

Number of animals:

24 human

Details on study design:

Closed patch tests with Finn Chambers were used. Purified water was used as a control. The chambers were removed at 2 days (D2). Test sites were read after chamber removal and at 4 days (D4). Skin reactions were graded according to the following scheme: 0= no reaction, + = questionable erythema, 1= definite erythema, 2 = erythema and induration and 3 = vesiculation.

Irritation parameter:

erythema score

Basis:

mean

Time point:

other: read after chamber removal (D2) and at 4 days (D4)

Remarks on result:

other: irritant to normal skin in pet. and in 70% IPA

Irritant / corrosive response data:

- Iodine in pet:
Most subjects did not react to 0.5% iodine in pet. 1 subject showed questionable erythema at D2, which had disappeared by D4. 2 subjects reacted to 1% iodine in pet. at D2. By D4, additional 3 subjects showed mild reactions. With 5% iodine in pet., only 4 subjects did not react. When increased to 10% iodine in pet., all 24 subjects reacted. Most developed erythema at D2 and induration or vesicles by D4.
- Iodine in 70% IPA:
When adding iodine to 70% IPA, a 0.5% concentration elicited questionable erythema in 8 subjects at D2, with stronger reactions seen in 3 subjects. With the 0.75% concentration, more than half of the subjects had questionable erythema to definite erythema at D2. 4 subjects had vesicles by D4.
- PVP-I and purified water:
1 subject developed reactions to 7.5% and 10% PVP-I at D4. None had any skin reactions to purified water.

Conclusions:

Mild-to-moderate reactions were observed in 75% of the subjects patched with 5% iodine in pet. at 2-4 days after application. Almost all subjects reacted to 10% iodine at D2 and D4, with 65% exhibiting erythema and induration or vesiculation. A large number (33%) of the subjects developed some reactions to the low concentration (0.5%) of iodine in 70% IPA at D2. Vesicles were seen in 54% of the subjects patched with 1% iodine in 70% IPA at D4. Only 1 subject reacted to 7.5% and 10% PVP-I. Iodine can be irritant to normal skin in pet. and in 70% IPA.

Executive summary:

A total of 24 fair-skinned, healthy volunteers without a history of iodine allergy, ranging in age from 18 to 65 years (mean age 49.5+10.7 SD), were recruited. Concentrations of 0.5%, 1%, 5% and 10% iodine in petrolatum (pet.), 0.5%, 0.75% and 1% iodine in 70% isopropyl alcohol (IPA) and 1%, 5%, 7.5% and 10% of povidone-iodine (PVP-I) were applied for 2 days to the intrascapular area on the back or to the volar forearm between cubital fossa and wrist using Finn Chambers on Scanpor. Test sites were read 2 days (D2) and 4 days (D4) after patch application. Mild-to-moderate reactions were observed in 75% of the subjects patched with 5% iodine in pet. at 2-4 days after application. Almost all subjects reacted to 10% iodine at D2 and D4, with 65% exhibiting erythema and induration or vesiculation. A large number (33%) of the subjects developed some reactions to the low concentration (0.5%) of iodine in 70% IPA at D2. Vesicles were seen in 54% of the subjects patched with 1% iodine in 70% IPA at D4. Only 1 subject reacted to 7.5% and 10% PVP-I. Iodine can be irritant to normal skin in pet. and in 70% IPA. Pet. possibly enhances skin contact with iodine, thus increasing its irritant capacity. Alcohol removes sebum from the skin surface, and it might increase iodine penetration into the skin, causing a higher degree of irritation. PVP-I is relatively non-irritant, because its iodine is complexed in an iodophor.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Eye irritation

Link to relevant study records

Reference

Endpoint:

eye irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From 2020-04-17 to 2020-04-17

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

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:

adopted 09. Oct. 2017

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Batch no.: 282 - 101314 / 282 - 101315
Purity: 100 %

Species:

cattle

Strain:

other: Bos primigenius Taurus

Details on test animals or tissues and environmental conditions:

SOURCE OF COLLECTED EYES
- Source: obtained from the slaughterhouse Müller Fleisch GmbH, Industri-estraße 42, 75217 Birkenfeld, Germany
- Characteristics of donor animals: between 12 and 60 months old
- Storage, temperature and transport conditions of ocular tissue: The eyes were transported in Hanks’ Balanced Salt Solution with 1 % Penicillin-Streptomycin solution (Penicillin 100 U/mL, Streptomycin 100 μg/mL) in a suitable cooled container within 1 hour and 7 minutes.

Vehicle:

unchanged (no vehicle)

Controls:

yes, concurrent positive control

yes, concurrent negative control

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied: 1035.3, 1003.4, 1003.3 mg
- The test item was ground with a mortar and pestle before use.

Duration of treatment / exposure:

4 hours

Number of animals or in vitro replicates:

three replicates for each treatment group (negative control solution, test item or positive control solution)

Details on study design:

SELECTION AND PREPARATION OF CORNEAS
After having carefully cleaned and sterilised the cornea holders, they were kept in the incubation chamber at 32 ± 1 °C.
After the arrival of the corneas, they were examined and only corneas which were free from damages were used.
The corneas were excised with a scalpel and cut from the globe with a 2-3 mm ring of sclera around the outside. Each cornea was transferred to a cornea holder in which prewarmed cMEM (32 ± 1 °C) without phenol red was filled. The holders were then incubated for 1 hour in the incubation chamber at 32 ± 1 °C. The formation of bubbles was prevented.
After the initial incubation, the medium was completely changed and the baseline opacity for each cornea was recorded. The baseline opacity was measured by placing the cornea holder in an opacitometer and recording the illuminance (unit: LUX).

QUALITY CHECK OF THE ISOLATED CORNEAS
None of the corneas showed an opacity greater than seven opacity units; therefore all corneas were used.

NUMBER OF REPLICATES
Three replicates

NEGATIVE CONTROL USED
HBSS: Hank’s Balanced Salt Solution (HBSS) 10-fold concentrated, diluted in demin. water (1:10), batch no.: T20200417

POSITIVE CONTROL USED
Imidazole solution: 20 % C3H4N2 (CAS-No. 288-32-4), dissolved in HBSS, batch no.: T20200417

APPLICATION DOSE AND EXPOSURE TIME
After removal of the pre-incubation medium (cMEM without phenol red), 750 μL of negative control solution, a defined amount of test item (1003.3 - 1035.3 mg) or 750 μL of positive control solution were applied to each replicate to the epithelial side of the cornea.
Exposure time of the controls and test item on the corneas was 4 hours at 32 ± 1 °C.

TREATMENT METHOD:
Closed chamber method for negative and positive controls; Open chamber-method” for test item

POST-INCUBATION PERIOD: no

REMOVAL OF TEST SUBSTANCE
- Number of washing steps after exposure period: After thorough rinsing the anterior chambers with cMEM with phenol red and final rinsing with cMEM without phenol red, the anterior chambers were filled with cMEM without phenol red.

METHODS FOR MEASURED ENDPOINTS:
- Corneal opacity: Each cornea holder was placed in the opacitometer and the final illuminance value of each cornea was recorded at once.
- Corneal permeability: passage of sodium fluorescein dye measured with the aid of microtiter plate reader (OD492)

SCORING SYSTEM: In Vitro Irritancy Score (IVIS)

DECISION CRITERIA: The decision criteria as indicated in the TG was used.

Irritation parameter:

in vitro irritation score

Value:

43 539.36

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

other: it is possible that the IVIS value of the test item is wrongly too high, because the test item color could not be removed

Other effects / acceptance of results:

OTHER EFFECTS:
- Visible damage on test system: At the end of the test it was observed, that all three cornea replicates of the test item were swollen compared to the negative control.

ACCEPTANCE OF RESULTS:
- Acceptance criteria met for negative control: yes
- Acceptance criteria met for positive control: yes

Illuminance Values:

Parameter	Negative Control			Test Item			Positive Control
	1.Rep.	2.Rep.	3.Rep.	1.Rep.	2.Rep.	3.Rep.	1.Rep.	2.Rep.	3.Rep.
(I) Measured values before exposure	1025	1006	1009	1046	1047	1033	1004	1007	999
(I) Measured values after exposure	1024	1010	1023	1*	1*	1*	349	337	346

* Note: due to the intrinsic colored cornea induced by the test item, the LUX value of all three test item replicates was 1.

Opacity Values Test Item and Positive Control:

Parameter	Test Item			Positive Control
	1.Rep.	2.Rep.	3.Rep.	1.Rep.	2.Rep.	3.Rep.
Opacity before exposure	2.25	2.21	2.77	3.99	3.86	4.21
Opacity after exposure	43541.46	43541.46	43541.46	85.46	89.90	86.54
Opacity Difference	43539.21	43539.25	43538.69	81.47	86.04	82.33
Opacity Difference corrected	43539.45	43539.49	43538.93	81.71	86.28	82.57
MeanOpacity Difference corrected	43539.29*			83.52

* Note: the high opacity value of the test item is due to the second opacity measurement. The intrin-sic color of the test item had an influence on the opacity result. The turbidity of the cornea could not be determined correctly; only the infiltrated test item color in the cornea could be measured.

Optical density at 492 nm of Negative Control, Test Item and Positive Control:

Parameter	Negative Control			TestItem			Positive Control
	1.Rep.	2.Rep.	3.Rep.	1.Rep.	2.Rep.	3.Rep.	1.Rep.	2.Rep.	3.Rep.
1.Measurement	0.043	0.041	0.045	0.044	0.047	0.052	1.485	1.040	1.967
2.Measurement	0.043	0.042	0.044	0.043	0.048	0.054	1.474	1.033	1.930
3.Measurement	0.043	0.043	0.044	0.045	0.045	0.054	1.471	1.027	1.919
1.Measurement – blank	0.0067	0.0047	0.0087	0.0077	0.0107	0.0157	1.4487	1.0037	1.9307
2.Measurement – blank	0.0067	0.0057	0.0077	0.0067	0.0117	0.0177	1.4377	0.9967	1.8937
3.Measurement – blank	0.0067	0.0067	0.0077	0.0087	0.0087	0.0177	1.4347	0.9907	1.8827
Mean of each replicate	0.0067	0.0057	0.0080	0.0077	0.0103	0.0170	1.4403	0.9970	1.9023
Mean of the 3 replicates	0.0068			--			--
Corrected	--	--	--	0.0009	0.0036	0.0102	1.4336	0.9902	1.8956
Corrected mean of the 3 replicates	--			0.0049			1.4398

Interpretation of results:

other: No conclusive result achieved

Conclusions:

Under the conditions of this test, the test item Iodine induced serious eye damage on the cornea of the bovine eye. The calculated mean IVIS was 43539.36.
According to OECD Guideline no. 437 (Oct. 2017), a substance with an IVIS > 55 induces serious eye damage, that should be classified as UN GHS Category I.
As the intrinsic color of the test item could not be removed from the cornea after the 4 hour incubation, the result of this study must be seen with reservations. It is possible that the IVIS value is wrongly too high and the opacity could not be determined correctly, because of the intrinsic color of the test item that could not be removed from the cornea.
Therefore no conclusive result could be achieved within this study.

Executive summary:

An in vitro study was performed to assess corneal damage potential of Iodine by quantitative measurements of changes in opacity and permeability in a bovine cornea following OECD Guideline 437 and EU Method B.47.

As test system bovine corneas were used. They were collected from slaughtered cattle that were between 12 and 60 months old.

The test item Iodine was brought onto the cornea of a bovine eye which previously had been incubated with cMEM without phenol red at 32 ± 1 °C for 1 hour and whose opacity had been determined. The test item was incubated on the cornea for 4 hours at 32 ± 1 °C. After removal of the test item, it could be observed that the whole cornea was coloured by the test item. Afterwards the opacity and permeability values were measured.

The test item was tested neat. No observations were made which might cause doubts concerning the validity of the study.

 

Under the conditions of this test, the test item Iodine induced serious eye damage on the cornea of the bovine eye. The calculated mean IVIS was 43539.36.

According to OECD Guideline no. 437 (Oct. 2017), a substance with an IVIS > 55 induces serious eye damage, that should be classified as UN GHS Category I.

As the intrinsic color of the test item could not be removed from the cornea after the 4 hour incubation, the result of this study must be seen with reservations. It is possible that the IVIS value is wrongly too high and the opacity could not be determined correctly, because of the intrinsic color of the test item that could not be removed from the cornea.

Therefore no conclusive result could be achieved within this study.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Skin irritation/corrosion: 

Several sources of data give indications on the potential effects of iodine to the skin.

 

CHEMINFO by the Canadian Centre for Occupational Health and Safety (CCOHS) indicates “crystalline iodine or strong solutions are severe skin irritants. Iodine crystals can cause severe penetrating injury (corrosive tissue destruction) at the point of contact. Solutions have caused crusting, burns (inflammatory reactions), skin eruptions (weeping) and fever. Individual susceptibility to such reactions shows great variations; some persons react after momentary contact with weak solutions, whereas others do not react after repeated contact with strong solutions".

 

Sax’s Dangerous Properties of Industrial Materials: "Iodine is a strong irritant of the mucous membrane, respiratory tract, eyes and skin". 

 

IPCS/INCHEM: “Concentrated iodine is corrosive. Main risks in acute exposure to high iodine concentrations are largely due to the highly corrosive effect of iodine on the entire gastrointestinal tract and resultant shock. Dermal application of strong iodine solutions may result in burns.

 

Hazardous Substance Database: “Ingestion of iodine may cause corrosive effect...inhalation of iodine vapour may result in severe pulmonary irritation...dermal application of strong iodine solutions may result in burns.”

 

According to Lee et al. (2005) iodine is a well-known local irritant which can cause burns. In 25 subjects exposed by patch application, the irritation threshold was seen in 1% iodine in petrolatum. 5% and 10% iodine in petrolatum resulted in clear irritation (vesicles). Note that vesicles are an indication of irritation, not corrosion, as they represent disturbances at the epidermal-dermal interface (OECD, 1999).

 

Iodine and concentrated solutions, including U.S.P. tincture, are classed as poisons because of their irritating effects to the gastrointestinal tract (Lyday, P. 2005).

 

Although data is consistent on potential effects of the substance on skin, documentation available is not adequate to make a clear difference on whether iodine is corrosive or irritant to the skin. No reference to primary sources on animal studies or observational human experience are made in order to evaluate exposure and if severity and persistence of the effects were objectively described.

 

Based on the equivocal information from published data, two independent in vitro skin corrosion studies were assessed. Both studies demonstrated non-corrosive effects of the substance under the experimental conditions. Following the testing strategy from OECD guideline 404, an in vitro skin irritation study (following EC guideline B.46) was conducted. Results from this in vitro skin irritation study concluded that iodine was irritant under testing conditions and is thus classified as skin irritant category 2. This validated method is accepted by the European Union as a stand-alone replacement test for the rabbit in vivo test for classifying GHS category 2 irritant substances. Then, no further tests are deemed necessary.

 

Eye irritation/corrosion:

Several sources of data give indications on the potential effects of iodine to the eye.

Published data:

Two peer-reviewed references give indications on the irritating properties of iodine to eyes (Grant, 1986 and Lewis, 1996). This data is in line with point 3.3.2.3. of CLP Annex I which indicates that skin irritant substances (category 2) may be considered as leading to eye irritation (category 2).

Test data:

An in vitro study was performed to assess corneal damage potential of Iodine by quantitative measurements of changes in opacity and permeability in a bovine cornea following OECD Guideline 437 and EU Method B.47. No conclusive result could be achieved because of the intrinsic color of the test item that could not be removed from the cornea and it is possible that the IVIS value is wrongly too high and the opacity could not be determined correctly.

 

In accordance with COMMISSION REGULATION (EC) No 440/2008 of 30 May 2008 laying down test methods pursuant to Regulation (EC) No 1907/2006 of the European Parliament and of the Council on the Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH), as existing in vitro data from validated and internationally accepted methods showing severe irritant effects on skin, no testing is needed. And also no in vitro eye corrosion/irritation test can discriminate between Serious eye damage (Category 1) or Eye irritation (category 2), in vivo test cannot be run as iodine is known to be corrosivity or severe irritancy to the eye. Therefore, no further eye corrosion/irritation testing is required. 

 

 

References: 

- Grant, W.M. Toxicology of the eye. 3rd ed. Springfield, IL: Charles C. Thomas Publisher, 1986., p. 519.

- Lee, S.K., Zhai, H., Maibach, H. 2005. Allergic contact dermatitis from iodine preparations: a conundrum. Contact Dermatitis 52: 184-187.

- Lewis, R.J. Sax's Dangerous Properties of Industrial Materials. 9th ed. Volumes 1 -3. New York, NY: Van Nostrand Reinhold, 1996., p. 1197.

- OECD, 1999. OECD Environmental Health and Safety Publications. Series on Testing and Assessment No. 16. Detailed review document on classification systems for skin irritation/corrosion in OECD member countries.

Justification for classification or non-classification

Skin irritation / corrosion:

Two independent in vitro skin corrosion studies (OECD 435): negative

In vitro skin irritation (B.46) test: positive

Based on results from test B.46 (In vitro skin irritation: reconstructed human epidermis model test), iodine is classified as per Regulation (EC) No 1272/2008 as skin irritant (category 2).

Eye irritation:

BCOP test (OECD 437): No conclusive result could be achieved

Skin irritant: Category 2

 

No conclusive result could be achieved in the BCOP test, but based on the classification for skin irritant (category 2), iodine is classified as eye irritant (category 2) according to Regulation (EC) No 1272/2008.