Hydrogen chloride

Eye irritation

Administrative data

Endpoint:

eye irritation

Remarks:

other: ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

The study was performed on 14 March 2013

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Study conducted in compliance with agreed protocols, with no or minor deviations from standard test guidelines and/or minor methodological deficiencies, which do not affect the quality of the relevant results. The study report was conclusive, done to a valid guideline and the study was conducted under GLP conditions.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2013

Report date:

2013

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: OECD 437

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

Date of Inspection : 10 July 2012 Date of Signature : 19 July 2013

Test material

Test material information

Constituent 1

Reference substance name:

Hydrochloric acid

IUPAC Name:

Hydrochloric acid

Test material form:

other: Liquid

Details on test material:

Sponsor's identification : Hydrochloric Acid
Description : clear colourless liquid
Lot number : SZBC1030V
Purity : 37.5%
Date received : 08 October 2012
Expiry date : 24 September 2015
Storage conditions : room temperature in the dark

Test animals / tissue source

Species:

other: Excised Bovine Cornea

Strain:

other: Strain: not applicable

Details on test animals or tissues and environmental conditions:

Not applicable

Test system

Vehicle:

other: Deionised Water

Controls:

no

Amount / concentration applied:

TEST ITEM

Concentrations prepared:
1%, 5% and 10% w/w in deionised water.

Amounts(s) applied (volume or weight with unit):
0.75 mL of the test item was applied to triplicate corneas.

VEHICLE
Deionised Water.

Duration of treatment / exposure:

The test item dilutions were applied for 10 minutes followed by an incubation period of 120 minutes.

Observation period (in vivo):

Not applicable

Number of animals or in vitro replicates:

Not applicable

Details on study design:

TEST SITE
Area of exposure:
0.75 mL of each test item concentration was applied to each cornea.

PERCENTAGE COVERAGE:
The test item was topically applied to the cornea. The holders were gently tilted back and forth to ensure a uniform application of the item over the entire cornea.

EXPOSURE:
The test item dilutions were applied for 10 minutes followed by an incubation period of 120 minutes.

REMOVAL OF TEST ITEM
-Washing (if done):
At the end of the exposure period the test item concentrations were removed from the anterior chamber and the cornea was rinsed three times with fresh complete MEM containing phenol red before a final rinse with complete MEM.

EVALUATION OF RESULTS:
Results from the two test method endpoints, opacity and permeability, were combined in an empirically derived formula to generate an In Vitro Irritancy Score.

Opacity Measurement:
The change in opacity for each cornea (including the negative control) was calculated by subtracting the initial opacity reading from the final opacity reading. These values were then corrected by subtracting from each the average change in opacity observed for the negative control corneas. The mean opacity value of each treatment group was then calculated by averaging the corrected opacity values of each cornea for that treatment group.

Permeability Measurement:
The corrected OD492 was calculated by subtracting the mean OD492 of the negative control corneas from the OD492 value of each treated cornea. The OD492 value of each treatment group was calculated by averaging the corrected OD492 values of the treated corneas for the treatment group.

In Vitro Irritancy Score:
The following formula was used to determine the in vitro score:
In Vitro Irritancy Score = mean opacity value + (15 x mean OD492 value)
Additionally, the opacity and permeability values were evaluated independently to determine whether the test item induced a response through only one of the two endpoints.

Visual Observation:
The condition of the cornea was visually assessed immediately after rinsing and at the final opacity measurement.

DATA INTERPRETATION:
An in vitro irritancy score greater than or equal to 55.1 is defined as an ocular corrosive or severe irritant.

Results and discussion

In vivo

Results

Irritation parameter:

cornea opacity score

Basis:

other: Mean Score of Opacity & Permeability

Time point:

other: 120 Minutes Post Rinsing

Max. score:

1

Reversibility:

other: Not applicable

Remarks on result:

other: See In Vitro Irritancy Scores below:

Irritant / corrosive response data:

Treatment In Vitro Irritancy Score
1% w/w Test Item 2.4
5% w/w Test Item 100.0
10% w/w Test Item 158.1
Negative Control 3.5
Positive Control 35.9
Vehicle Control 0.0

Other effects:

The corneas treated with 1% w/w test item were clear post treatment and post incubation. The corneas treated with 5% w/w and 10% w/w test item were cloudy post treatment and post incubation. The corneas treated with the negative control item were clear post treatment and post incubation. The corneas treated with the positive control item were cloudy post treatment and post incubation. The corneas treated with the vehicle control item were clear post treatment and post incubation.

Any other information on results incl. tables

RESULTS

Corneal Opacity and Permeability Measurement

Individual and mean corneal opacity measurements and individual and mean corneal permeability measurements are given in Tables 1 and 2.

Corneal Epithelium Condition

The condition of each cornea post treatment and post incubation is given in Tables 3 and 4. The corneas treated with 1% w/w test item were clear post treatment and post incubation. The corneas treated with 5% w/w and 10% w/w test item were cloudy post treatment and post incubation. The corneas treated with the negative control item were clear post treatment and post incubation. The corneas treated with the positive control item were cloudy post treatment and post incubation. The corneas treated with the vehicle control item were clear post treatment and post incubation.

In Vitro Irritancy Score

The results are summarised as follows:

Treatment	In VitroIrritancy Score
1% w/w Test Item	2.4
5% w/w Test Item	100.0
10% w/w Test Item	158.1
Negative Control	3.5
Positive Control	35.9
Vehicle Control	0.0

Criterion for an Acceptable Test

The positive control In Vitro Irritancy Score was within the range of 30.9 to 67.7. The positive control acceptance criterion was therefore satisfied.

Table 1 Individual and Mean Corneal Opacity and Permeability Measurements, Control Items

Treatment	Cornea Number	Opacity					Permeability (OD)		In vitroIrritancy Score
		Pre-Treatment	Post-Treatment	Post-Incubation	Post-Incubation-Pre‑Treatment	Corrected Value		Corrected Value
Negative Control	1	2	4	6	4		0.032
	2	2	2	5	3		0.030
	3	2	2	4	2		0.030
					3.0*		0.031 +		3.5
Positive Control	4	2	21	26	24	21.0	1.145	1.114
	5	2	20	25	23	20.0	0.892	0.861
	6	3	23	28	25	22.0	1.034	1.003
						21.0·		0.993·	35.9
Vehicle Control	7	2	3	5	3	0.0	0.039	0.008
	8	3	4	5	2	0.0	0.018	0.000
	9	1	2	2	1	0.0	0.018	0.000
						0.0·		0.003·	0.0

OD= Optical density * = Mean of the post incubation - pre‑treatment values   + = Mean permeability  · = Mean corrected value

Table 2 Individual and Mean Corneal Opacity and Permeability Measurements, Test Item Dilutions

Treatment	Cornea Number	Opacity					Permeability (OD)		In vitroIrritancy Score
		Pre-Treatment	Post-Treatment	Post-Incubation	Post-Incubation-Pre‑Treatment	Corrected Value		Corrected Value
1%w/wTest Item	10	3	9	9	6	3.0	0.028	0.000
	11	3	6	7	4	1.0	0.030	0.000
	12	2	6	8	6	3.0	0.049	0.018
						2.3·		0.006·	2.4
5%w/wTest Item	13	1	40	96	95	92.0	0.025	0.000
	14	2	43	98	96	93.0	0.083	0.052
	15	3	55	120	117	114.0	0.043	0.012
						99.7·		0.022·	100.0
10%w/wTest Item	16	2	117	162	160	157.0	0.045	0.014
	17	4	109	160	156	153.0	0.111	0.080
	18	2	94	165	163	160.0	0.232	0.201
						156.7·		0.099·	158.1

OD= Optical density ·= Mean corrected value

Table 3 Corneal Epithelium Condition Post Treatment and Post Incubation, Control Items

Treatment	Cornea Number	Observation
		Post Treatment	Post Incubation
Negative Control	1	clear	clear
	2	clear	clear
	3	clear	clear
Positive Control	4	cloudy	cloudy
	5	cloudy	cloudy
	6	cloudy	cloudy
Vehicle Control	7	clear	clear
	8	clear	clear
	9	clear	clear

Table 4 Corneal Epithelium Condition Post Treatment and Post Incubation, Test Item Dilutions

Treatment	Cornea Number	Observation
		Post Treatment	Post Incubation
1% w/w Test Item	10	clear	clear
	11	clear	clear
	12	clear	clear
5% w/w Test Item	13	cloudy	cloudy
	14	cloudy	cloudy
	15	cloudy	cloudy
10% w/w Test Item	16	cloudy	cloudy
	17	cloudy	cloudy
	18	cloudy	cloudy

Applicant's summary and conclusion

Interpretation of results:

other: Various Concentrations, see below:

Remarks:

Criteria used for interpretation of results: expert judgment

Conclusions:

The test item was considered not to be an ocular corrosive or severe irritant at 1% w/w in deionised water and therefore did not require labelling as severe ocular irritant.
The test item was considered to be an ocular corrosive or severe irritant at 5% and 10% w/w in deionised water and therefore required to be classified as EU DSD Symbol “Xi” Risk Phrase R41, EU CLP and UN GHS H318 Category 1.

Executive summary:

Introduction. A study was performed to assess the ocular irritancy potential of various concentrations of the test item, Hydrochloric acid, to the isolated bovine cornea. The method was designed to be compatible with the following:

OECD Guidelines for the Testing of Chemicals No. 437 (2009) “Bovine Corneal Opacity and Permeability Assay”

Preparation of Test Item: The sponsor was consulted prior to determination of the concentrations to be tested.

Concentrations prepared:
1%, 5% and 10% w/w in deionised water.

Method. The test item dilutions were applied for 10 minutes followed by an incubation period of 120 minutes. Negative, positive and vehicle control items were tested concurrently. The two endpoints, decreased light transmission through the cornea (opacity) and increased passage of sodium fluorescein dye through the cornea (permeability) were combined in an empirically derived formula to generate an In Vitro Irritancy Score (IVIS).

Results. The in vitro Irritancy scores are summarised as follows:

Treatment	In Vitro Irritancy Score
1% w/w Test Item	2.4
5% w/w Test Item	100.0
10% w/w Test Item	158.1
Negative Control	3.5
Positive Control	35.9
Vehicle Control	0.0

Conclusion. The test item was considered not to be an ocular corrosive or severe irritant at 1% w/w in deionised water and therefore did not require labelling as severe ocular irritant.

The test item was considered to be an ocular corrosive or severe irritant at 5% and 10% w/w in deionised water and therefore required to be classified as EU DSD Symbol “Xi” Risk Phrase R41, EU CLP and UN GHS H318 Category 1