1,3-diiodopropane

Endpoint summary

Description of key information

For skin irritation, one valid in vitro experiment, following OECD Guideline 431 and EU Method B.40-BIS, was performed. Two tissues of the human skin model EpiDerm™ were treated with the test item for 3 minutes and 1 hour, respectively. The test item was applied to each tissue and spread to match the tissue size. Demineralised water was used as negative control, 8 M KOH was used as positive control. After treatment, the respective substance was rinsed from the tissues. Then, cell viability of the tissues was evaluated by addition of MTT, which can be reduced to a blue formazan. Formazan production was evaluated by measuring the optical density (OD) of the resulting solution. The positive control showed clear corrosive effects for both treatment intervals.

After 3 minutes treatment with the test item, the mean value of relative tissue viability was reduced to 78.2% (above the 50% threshold for corrosion potential). After 1 hour treatment, the mean value of relative tissue viability was increased to 100.1% (above the 15% threshold for corrosion potential). Therefore, the test item 1,3-Diiodopropane is considered non-corrosive to skin in the Reconstructed Human Epidermis (RHE) Test Method.

For eye irritation, one valid experiment was performed according to the Bovine Corneal Opacity and Permeability (BCOP) Test Method following OECD Guideline 437 and EU Method B.47. The test item 1,3-Diiodopropane was applied onto the cornea of a bovine eye which had been previously incubated with cMEM without phenol red at 32 ±1 °C for 1 hour and whose opacity had been measured. Following incubation on the cornea for 10 minutes at 32 ±1 °C and after removal of the test item and 2 hours post-incubation, opacity and permeability values were measured. Hank’s Balanced Salt Solution (HBSS) was used as negative control showing no irritating effect on the cornea. Dimethylformamide (DMF) undiluted was used as positive control inducing serious eye damage on the cornea and was within two standard deviations of the current historical mean.

Under the conditions of this study, the test item 1,3-Diiodopropane showed no effects on the cornea of the bovine eye. The calculated mean IVIS was 0.73. Thus, according to OECD Guideline no. 437 (Oct. 2017), a substance with an IVIS ≤ 3 requires no classification for eye irritation or serious eye damage.

Another experiment according to OECD Guideline 439 was performed. Three tissues of the human skin model EpiDerm™ were treated with the test item for 60 minutes. The test item was applied directly to each tissue and spread to match the tissue size (0.63 cm²; as indicated by the supplier). DPBS-buffer was used as negative control and 5% SDS solution was used as positive control.

After treatment with the negative control, the mean absorbance value was within the required acceptability criterion of 0.8 ≤ mean OD ≤ 2.8; OD was 1.6.

The positive control showed clear irritating effects. The mean value of relative tissue viability was reduced to 11.5% (required:≤20%). The variation within the tissue replicates of negative control, positive control and test item was acceptable (required: ≤ 18%).

After the treatment with the test item, the mean value of relative tissue viability was reduced to 83.9%. This value is above the threshold for skin irritation potential (50%). Test items that induce values above the threshold of 50% are considered non-irritant to skin. Therefore, the test item 1,3-Diiodopropane is considered non-irritant to skin in the Reconstructed human Epidermis (RhE) Test Method.

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Reference 1

Endpoint:

skin irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2020

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

18. Jun. 2019

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test system:

human skin model

Source species:

human

Cell type:

non-transformed keratinocytes

Details on animal used as source of test system:

The test item is applied topically to a three-dimensional human skin model, comprising of non-transformed, human-derived epidermal keratinocytes, which have been cultured to form a multi-layered, highly differentiated model of the human epidermis. It consists of organized basal, spinous and granular layers, and a multi-layered stratum corneum con-taining intercellular lamellar lipid layers representing main lipid classes analogous to those found in vivo.

Vehicle:

water

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

The liquid test item was applied without preparation (50 µL).

Duration of treatment / exposure:

3 minutes and 1 hour

Duration of post-treatment incubation (if applicable):

Following exposure to test item and removal thereof, the tissues were incubated with MTT solution for 3 hours at 37 ±1 °C and 5.0 ±1% CO2.

Number of replicates:

10 replicates for isopropanol (blank); for negative control, test item and positive control 2 tissues with 3 replicates each were measured.

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

Test item, 3 minutes incubation

Value:

78.2

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

Test item, 1 hour incubation

Value:

100.1

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

Positive control, 3 minutes incubation

Value:

13.9

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

Positive control, 1 hour incubation

Value:

5.6

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

As blank, the optical density (OD 570 nm) of isopropanol (blank value) was measured in 12 wells of the 96-well-plate. The measured values and their mean are given in the following table:

Replicate	1	2	3	4	5	6	Mean
Absorbance	0.034	0.34	0.035	0.035	0.034	0.033	0.034
Replicate	7	8	9	10	11	12
Absorbance	0.034	0.034	0.034	0.033	0.033	0.035

 

The absorbance values (OD 570 nm) of negative control, test item and positive control are given in the following table:

Incubation	Negative Control		Test Item		Positive Control
	Tissue 1	Tissue 2	Tissue 1	Tissue 2	Tissue 1	Tissue 2
3 min	2.042	1.900	1.622	1.404	0.315	0.281
	1.985	1.894	1.634	1.453	0.316	0.285
	2.000	1.886	1.632	1.450	0.317	0.284
1 h	1.684	1.675	1.770	1.582	0.117	0.126
	1.670	1.677	1.779	1.586	0.129	0.129
	1.668	1.689	1.767	1.591	0.124	0.128

 

From the measured absorbances, the mean absorbance of isopropanol was subtracted. The corrected mean and relative standard deviation (RSD) of the two tissues were also calculated.

Mean Absorbance Values of the 3 Minutes Experiment

Designation	Negative Control	Test Item	Positive Control
Mean – blank (tissue 1)	1.975	1.595	0.282
Mean – blank (tissue 2)	1.859	1.402	0.249
Mean of the two tissues	1.917	1.499	0.266
RSD	4.3%	9.1%	8.7%

 

Mean Absorbance Values of the 1 h Experiment

Designation	Negative Control	Test Item	Positive Control
Mean – blank (tissue 1)	1.640	1.738	0.089
Mean – blank (tissue 2)	1.646	1.552	0.094
Mean of the two tissues	1.643	1.645	0.092
RSD	0.3%	8.0%	3.3%

 

Comparison of Tissue Viability: For the test item and the positive control, the following percentage values of mean tissue viability were calculated in comparison to the mean of the negative controls:

Test Item	Positive Control	Incubation
78.2%	13.9%	3 min
100.1%	5.6%	1 h

 

Assessment and Validity

Corrosivity of the Test Item: The mean value of relative tissue viability of the test item was reduced to 78.2% after 3 minutes treatment. This value is above the threshold for corrosivity (50%). After 1 hour treatment, the mean value of relative tissue viability of the test item was increased to 100.1%, lying above the threshold for corrosivity (15%). Therefore, the test item is considered as non-corrosive to skin.

Validity: The criterion for optical density of the negative control (≥ 0.8 and ≤ 2.8) was fulfilled: optical density was 1.9 (3 minutes) and 1.6 (1 hour). The positive control showed clear corrosive effects. The criterion for the viability of the 1 hour experiment, expressed as % of the negative control (< 15%), was fulfilled, too. The mean value of relative tissue viability was 5.6%. The values for negative control and for positive control were within the range of historical data of the test facility.

Therefore, the experiment is considered valid.

Interpretation of results:

GHS criteria not met

Conclusions:

The test item is considered non-corrosive to skin. After 3 minutes treatment, the mean value of relative tissue viability of the test item was reduced to 78.2%, well above the threshold for corrosivity (50%). After 1 hour treatment the mean value of relative tissue viability of the test item was increased to 100.1%, also well above the threshold for corrosivity (15%).

Executive summary:

One valid experiment, following OECD Guideline 431 and EU Method B.40-BIS, was performed. Two tissues of the human skin model EpiDerm™ were treated with the test item for 3 minutes and 1 hour, respectively. The test item was applied to each tissue and spread to match the tissue size. Demineralised water was used as negative control, 8 M KOH was used as positive control. After treatment, the respective substance was rinsed from the tissues. Then, cell viability of the tissues was evaluated by addition of MTT, which can be reduced to a blue formazan. Formazan production was evaluated by measuring the optical density (OD) of the resulting solution.

After treatment with the negative control, the absorbance values were within the required acceptability criterion of mean OD ≥ 0.8 and ≤ 2.8 for both treatment intervals thus, showing the quality of the tissues. The OD were 1.9 (3 minutes experiment) and 1.6 (1 hour experiment).

The positive control showed clear corrosive effects for both treatment intervals. The mean relative tissue viability value was reduced to 5.6% for the 1 hour treatment.

After 3 minutes treatment with the test item, the mean value of relative tissue viability was reduced to 78.2%. This value is above the threshold for corrosion potential (50%). After 1 hour treatment, the mean value of relative tissue viability was increased to 100.1%. This value is above the threshold for corrosion potential (15%).

Therefore, the test item 1,3-Diiodopropane is considered non-corrosive to skin in the Reconstructed Human Epidermis (RHE) Test Method.

Reference 2

Endpoint:

skin irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

July 2020

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 439 (In Vitro Skin Irritation: Reconstructed Human Epidermis Test Method)

Version / remarks:

June 2019

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test system:

human skin model

Source species:

human

Cell type:

non-transformed keratinocytes

Details on animal used as source of test system:

The test system is a commercially available EpiDerm™-Kit, procured by MatTek.
The EpiDerm™ tissue consists of human-derived epidermal keratinocytes which have been cultured to form a multi-layered, highly differentiated model of the human epidermis. It consists of organized basal, spinous and granular layers, and a multi-layered stratum corneum containing intercellular lamellar lipid layers representing main lipid classes analogous to those found in vivo. The EpiDerm™ tissues are cultured on specially prepared cell culture inserts. EpiDerm™ tissues were procured from MatTek In Vitro Life Science Laboratories, Bratislava, Designation of the kit EPI-218-SIT, Batch no.: 30878.

Details on test system:

Negative Control: Dulbecco’s Phosphate Buffered Saline (DPBS buffer without CaCl2 and without MgCl2).
Positive Control: Sodium dodecyl sulphate (SDS), CAS No. 151-21-3, solution in demineralised water containing 5% SDS. Procured from MatTek In Vitro Life Science Laboratories, batch no.: 052020LHB.
MTT: 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide (= MTT), which can be reduced to a blue formazan. A MTT stock solution of 5 mg/mL in DPBS buffer was prepared and stored in aliquots of 2 mL in the freezer (–20 ±5 °C). 2 mL of the stock solution were thawed and diluted with 8 mL of medium. This MTT-solution with the resulting concentration of 1 mg/mL was used in the test; for the pre-test (testing the ability of direct MTT reduction), the stock solution was thawed and diluted with serum-free MEM directly before use whereas for the main test, the stock solution was thawed and diluted with assay medium directly before use.
MEM with Phenol Red for Pre-Test: Serum-free MEM (Minimum Essential Medium), procured by Life Technologies GmbH, batch no.: 2125609
Assay Medium: Serum-free DMEM (Dulbecco’s Modified Eagle’s Medium), procured by MatTek In Vitro Life Science Laboratories, batch no.: 070220LHB
Isopropanol: CH3-CH(OH)-CH3, for synthesis., ≥99.5 %, batch no.: 457264070, used as extracting solvent for formazan
DPBS-buffer: The solution was used for the rinsing of the tissues and as solvent for MTT concentrate, it was also used as negative control. A subset was procured by MatTek In Vitro Life Science Laboratories; the other subset was prepared by LAUS GmbH.
Composition of the subset from MatTek In Vitro Life Science Laboratories (batch no.: 042820MSA): KCl 0.2 g, KH2PO4 0.2 g, NaCl 8.0 g, Na2HPO4 * 7H2O 2.16 g and H2O ad to 1 L. Composition of the subset from LAUS GmbH (batch no.: T20190910): KCl 0.4 g, KH2PO4 0.4 g, NaCl 16.0 g, Na2HPO4 * 2H2O 2.87 g and H2O ad to 2 L.
The buffer which was procured by MatTek Corporation was used as negative control and for rinsing the test item from the tissues. The buffer which was prepared by LAUS GmbH was used as solvent for MTT concentrate and for rinsing the outside of the inserts at the end of the incubation time with MTT.
Test Vessels
All vessels used are made of glass or sterilised plastic. The glassware was sterilised before use by autoclaving. The following vessels were used: 6-well-plates, 24-well plates, and 96-well-plate.
Demonstration of Proficiency: The validity of the skin irritation study at LAUS GmbH was demonstrated in a proficiency study. For this purpose, 10 proficiency chemicals (indicated by the OECD 439 guideline) were tested. All of the 10 proficiency chemicals were correctly categorized. Therefore, the proficiency of the skin irritation study was demonstrated.

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

30 µL of the test item were applied per test

Duration of treatment / exposure:

1 hour exposure, 35 minutes therof in incubator

Duration of post-treatment incubation (if applicable):

see above and thereafter 23 hours post-incubation.

Number of replicates:

3 replicates of negative control, positive control and test item, each

Details on study design:

Treatment: One plate (3 tissues) was used as negative control; each tissue was treated with 30 µL DPBS buffer, a nylon mesh was added in order to ensure sufficient contact with the tis-sue surface. One plate was used as positive control; each tissue was treated with 30 µL 5% SDS-solution; a nylon mesh was added in order to ensure sufficient contact with the tissue surface.
One plate was used for treatment with the test item: 30 µL of the test item were applied, and a nylon mesh was added in order to ensure sufficient contact with the tissue surface. Tissues were dosed in 1-minute intervals. After dosing the last tissue, all plates were transferred into the incubator for 35 minutes at 37 ±1 °C and 5.0 ±1% CO2 and ≥ 95% relative humidity. 1 hour after the first application, the inserts were removed from the plates using sterile forceps and rinsed immediately in 1-minute intervals. After rinsing thoroughly with DPBS, each tissue was blotted with sterile cellulose tissue and then transferred into a new 6-well plate with fresh assay medium (0.9 mL). The surface of the inserts was then carefully dried with a sterile cotton tipped swab. Then, the tissues were set in the incubator for 23 hours at 37 ±1 °C and 5.0 ±1% CO2 and ≥ 95% relative humidity.
Medium Renewal: After post-incubation, the tissues were removed from the incubator and shaken for 5 minutes (120 rpm). 0.9 mL assay medium were filled in the lower row of the 6-well plate. Then the inserts were transferred into the lower row of the 6-well plate and set into the incubator for 19 hours and 40 minutes for post-incubation at 37 ±1 °C and 5.0 ±1% CO2 and ≥ 95% relative humidity.
MTT Assay: After a total incubation time of 42 hours and 40 minutes a 24-well plate was prepared with 300 µL freshly prepared MTT-solution (1 mg/mL) in each well. The tissues were blotted on the bottom and then transferred into the 24-well plate. Then the 24-well plate was set into the incubator for 3 hours at 37 ±1 °C and 5.0 ±1% CO2 and ≥ 95% relative humidity. After this time, the MTT-solution was aspirated and replaced by DPBS buffer. This was then aspirated, too, and replaced several times. At last, each insert was thoroughly dried and set into the empty, pre-warmed 24-well plate. Into each well, 2 mL isopropanol were pipetted, taking care to reach the upper rim of the insert. The plate was then shaken (120 rpm) for 2 hours at room temperature. After 2 hours, the inserts were pierced with an injection needle, taking care that all colour was extracted. The inserts were then discarded, and the content of each well was thoroughly mixed in order to achieve homogenisation. From each well, two replicates with 200 µL solution (each) were pipetted into a 96-well plate which was read in a plate spectrophotometer at 570 nm. In addition, eight wells of the 96-well plate were filled with 200 µl µL isopropanol each, serving as blank.

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

mean

Value:

83.9

Vehicle controls validity:

valid

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

no indication of irritation

Remarks:

± SD of mean tissue viability (%): 13.1%

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

tissue 1

Value:

88.9

Vehicle controls validity:

valid

Negative controls validity:

valid

Positive controls validity:

valid

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

tissue 2

Value:

69.1

Vehicle controls validity:

valid

Negative controls validity:

valid

Positive controls validity:

valid

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

tissue 3

Value:

93.8

Vehicle controls validity:

valid

Negative controls validity:

valid

Positive controls validity:

valid

Other effects / acceptance of results:

Assessment and Validity
Skin Irritation Potential of the Test Item: The mean value of relative tissue viability of the test item was reduced to 83.9% after the treatment. This value is above the threshold for skin irritation (50%). Therefore, the test item is considered as non-irritant to skin.
Validity and Acceptability: Validity criteria and results are stated as follows:
Criterion: OD of negative control to be ≥ 0.8 and ≤ 2.8  found 1.6  valid
Criterion: % tissue viability of positive control SDS to be ≤ 20% of negative control found 11.5%  valid
Criterion: SD of mean viability of the tissue replicates (%)to be ≤ 18%--> found 10.6% (negative control), 2.7% (positive control), 13.1% (test item)  all valid
All validity criteria were met and the values for negative control and for positive control were within the range of historical data of the test facility.

Measured Values: As blank, the optical density of isopropanol was measured in 8 wells of the 96-well plate. The measured values and their mean are given in table 1.

Table 1: Absorbance values blank isopropanol (OD 570 nm)

Replicate	1	2	3	4	5	6	7	8	Mean
Absorbance	0.038	0.035	0.035	0.036	0.036	0.035	0.035	0.035	0.036

 

The absorbance values of negative control, test item and positive control are given in the following table 2:

Table 2: Absorbance Values negative control, test item and positive control (OD 570 nm)

Designation	Measurement	Negative Control	Test Item	Positive Control
Tissue 1	1	1.558	1.430	0.230
	2	1.536	1.433	0.228
Tissue 2	1	1.487	1.120	0.252
	2	1.468	1.121	0.250
Tissue 3	1	1.797	1.515	0.168
	2	1.790	1.501	0.168

 

From the measured absorbances, the mean of each tissue was calculated, subtracting the mean absorbance of isopropanol as given in table 1. The mean of the three tissues was also calculated.

Table 3: Mean Absorbance Values

Designation	Negative Control	Test Item	Positive Control
Mean – blank (tissue 1)	1.511	1.396	0.193
Mean – blank (tissue 2)	1.442	1.085	0.215
Mean – blank (tissue 3)	1.758	1.472	0.132
Mean of the three tissues	1.570	1.318	0.180

 

Comparison of Tissue Viability: For the test item and the positive control, the following percentage values of tissue viability were calculated in comparison to the negative control:

Table 4: % Tissue Viability

Designation	Test Item 1,3-Diiodopropane	Positive Control
% Tissue viability (tissue 1)	88.9%	12.3%
% Tissue viability (tissue 2)	69.1%	13.7%
% Tissue viability (tissue 3)	93.8%	8.4%
% Tissue viability (mean)	83.9%	11.5%
± SD of mean tissue viability (%)	13.1%	2.7%

 

Interpretation of results:

GHS criteria not met

Conclusions:

The test item 1,3-Diiodopropane is considered as non-irritant to skin.

Executive summary:

One valid experiment was performed. Three tissues of the human skin model EpiDerm™were treated with the test item for 60 minutes. The test item was applied directly to each tissue and spread to match the tissue size (0.63 cm²; as indicated by the supplier).

DPBS-buffer was used as negative control and 5% SDS solution was used as positive control.

After treatment with the negative control, the mean absorbance value was within the required acceptability criterion of 0.8 ≤ mean OD ≤ 2.8; OD was 1.6.

The positive control showed clear irritating effects. The mean value of relative tissue viability was reduced to 11.5% (required:≤20%). The variation within the tissue replicates of negative control, positive control and test item was acceptable (required: ≤ 18%).

After the treatment with the test item, the mean value of relative tissue viability was reduced to 83.9%. This value is above the threshold for skin irritation potential (50%). Test items that induce values above the threshold of 50% are considered non-irritant to skin.

Therefore, the test item 1,3-Diiodopropane is considered non-irritant to skin in the Reconstructed human Epidermis (RhE) Test Method.

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:

experimental study

Adequacy of study:

key study

Study period:

2020

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 Ocular Corrosives and Severe Irritants)

Version / remarks:

9.10.2017

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Species:

cattle

Strain:

not specified

Details on test animals or tissues and environmental conditions:

Species from which cornea were derived: Bos primigenius Taurus (fresh bovine corneas)
Fresh bovine eyes were obtained from the slaughterhouse Müller Fleisch GmbH, Industriestraße 42, 75217 Birkenfeld, Germany, on the day of the test. The cattle were between 12 and 60 months old. The eyes were transported to the test facility 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.

Vehicle:

unchanged (no vehicle)

Controls:

yes, concurrent positive control

yes, concurrent negative control

Amount / concentration applied:

750 µL of the liquid test (undiluted)

Duration of treatment / exposure:

10 minutes exposure time for negative control solution, test item or positive control

Duration of post- treatment incubation (in vitro):

2 hours post-incubation

Number of animals or in vitro replicates:

3 replicates each for negative control solution, test item or positive control

Irritation parameter:

in vitro irritation score

Run / experiment:

mean ivis from triplicate measurement

Value:

0.73

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Opacity and Permeability Values: The illuminance (unit: LUX) values which were measured before and after exposure are given in the following table:

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	1030	1040	1037	1043	1048	1049	1055	1063	1063
(I) Measured values after exposure	1014	1015	1014	1000	990	1032	366	352	370

Rep. = Replicate

The values in the following tables present the calculated opacity values, according to evaluation:

Opacity Values Negative Control

Parameter	Negative Control
	1. Rep.	2. Rep.	3. Rep.
Opacity before exposure	3.47	3.06	3.18
Opacity after exposure	4.15	4.10	4.15
Opacity Difference	0.68	1.05	0.97
Mean Opacity Difference	0.90

Rep. = Replicate

 

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	2.93	2.73	2.69	2.45	2.14	2.14
Opacity after exposure	4.75	5.20	3.39	81.27	86.07	79.97
Opacity Difference	1.82	2.47	0.69	78.82	83.94	77.83
Opacity Difference corrected	0.92	1.57	-0.20	77.93	83.04	76.94
Mean Opacity Difference corrected	0.77			79.30

Rep. = Replicate

For the permeability measurement, three replicates for each treatment group were measured three times. cMEM without phenol red was measured as blank value as well. The optical density values at 492 nm are given in the following tables:

Optical density at 492 nm of Blank

Parameter	cMEM without phenol red
1. Measurement	0.036
2. Measurement	0.040
3. Measurement	0.037
Mean	0.038

 

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

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.
1.Measure-ment	0.040	0.040	0.040	0.044	0.036	0.032	0.688	1.177	1.325
2.Measure-ment	0.039	0.040	0.037	0.044	0.035	0.032	0.688	1.180	1.348
3.Measure-ment	0.038	0.041	0.040	0.043	0.036	0.033	0.690	1.162	1.378
1.Measure-ment – blank	0.0023	0.0023	0.0023	0.0063	-0.0017	-0.0057	0.6503	1.1393	1.2873
2.Measure-ment – blank	0.0013	0.0023	-0.0007	0.0063	-0.0027	-0.0057	0.6503	1.1423	1.3103
3.Measure-ment – blank	0.0003	0.0033	0.0023	0.0053	-0.0017	-0.0047	0.6523	1.1243	1.3403
Mean of each replicate	0.0013	0.0027	0.0013	0.0060	-0.0020	-0.0053	0.6510	1.1353	1.3127
Mean of 3 replicates	0.0018			--			--
Corrected	--	--	--	0.0042	-0.0038	-0.0071	0.6492	1.1336	1.3109
Corrected mean of 3 replicates	--			-0.0022			1.0312

Rep. = Replicate

IVIS Values: The calculated IVIS for each replicate and the corresponding means are presented in the following table:

Test Group	IVIS	Mean IVIS	Relative Standard Deviation IVIS
Negative Control HBSS	0.70	0.92	21.91%
	1.09
	0.99
Test Item 1,3-Diiodopropane	0.99	0.73	128.40%
	1.52
	-0.31
Positive Control DMF undiluted	87.66	97.44	6.74%
	100.04
	96.60

Note: the high relative standard deviation of the IVIS of the test item is due to mathematical reasons, as the respective means are very small.

Validity: According to the guideline, the test is considered as valid if the positive control causes an IVIS that falls within two standard deviations of the current historical mean. The mean IVIS of the negative control has to show an IVIS ≤ 3. The validity criteria and findings are given in the following table:

Parameter	Criterion	Found	Assessment
Mean IVIS of negative control HBSS	≤ 3	0.92	ok
Mean IVIS of positive control DMF undiluted	56.53 – 140.26	94.77	ok

 

Values for negative and positive controls were within the range of historical data of the test facility. Therefore, the test system was acceptable.

Assessment: According to OECD Guideline no. 437 (Oct. 2017), a substance with an IVIS ≤ 3 requires no classification for eye irritation or serious eye damage.

Classification Scheme

IVIS	UN GHS
≤ 3	No category
> 3 and ≤ 55	No prediction can be made
> 55	Eye damage Category I

 

In the negative control, no signs of eye irritation were observed. The positive control induced serious eye damage, which would be classified as GHS category I. The test item 1,3-Diiodopropane showed no effects on the cornea of the bovine eye. The calculated mean IVIS (In Vitro Irritancy Score) was 0.73.

The experiment is considered as sufficient for the classification of the test item, because all three replicates of the test item lead to the same assessment for the test item.

Interpretation of results:

GHS criteria not met

Conclusions:

Under the conditions of this study, the test item 1,3-Diiodopropane showed no effects on the cornea of the bovine eye.

Executive summary:

One valid experiment was performed according to the Bovine Corneal Opacity and Permeability (BCOP) Test Method following OECD Guideline 437 and EU Method B.47. Bovine corneas were used. They were collected from slaughtered cattle that were between 12 and 60 months old.

The test item 1,3-Diiodopropane was applied onto the cornea of a bovine eye which had been previously incubated with cMEM without phenol red at 32 ±1 °C for 1 hour and whose opacity had been measured.

The test item was incubated on the cornea for 10 minutes at 32 ±1 °C. After removal of the test item and 2 hours post-incubation, opacity and permeability values were measured. Hank’s Balanced Salt Solution (HBSS) was used as negative control. The negative control showed no irritating effect on the cornea and the calculated mean IVIS (In Vitro Irritancy Score) was 0.92. Dimethylformamide (DMF) undiluted was used as positive control. The positive control induced serious eye damage on the cornea and was within two standard deviations of the current historical mean. The calculated mean IVIS was 94.77.

Under the conditions of this study, the test item 1,3-Diiodopropane showed no effects on the cornea of the bovine eye. The calculated mean IVIS was 0.73. Thus, according to OECD Guideline no. 437 (Oct. 2017), a substance with an IVIS ≤ 3 requires no classification for eye irritation or serious eye damage.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

Based on two in vitro studies assessing skin corrosion and skin irritation as well as considering an in vitro study assessing eye irritation, that all turned out negative, the substance 1,3 -diiodopropane does not require classification and labelling for skin or eye irritation according to GHS and CLP (Regulation EC No 1272/2008).