Hexadecyl dihydrogen phosphate

Eye irritation

Administrative data

Endpoint:

eye irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

March 20, 2019 to March 21, 2Ol9

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2019

Report date:

2019

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 492 (Reconstructed Human Cornea-like Epithelium (RhCE) Test Method for Identifying Chemicals Not Requiring Classification and Labelling for Eye Irritation or Serious Eye Damage)

Version / remarks:

The MatTek Corporation In Vitro EpiOcula Eye Initation Test (OCL-200-EIT) (OECD 492)
Protocol: Epi0cularrM Eye Iritation Test (OCL 200-EIT) Protocol Date: 6/29/15

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Hexadecyl dihydrogen phosphate

EC Number:

222-581-1

EC Name:

Hexadecyl dihydrogen phosphate

Cas Number:

3539-43-3

Molecular formula:

C16H35O4P

IUPAC Name:

hexadecyl dihydrogen phosphate

Test material form:

solid: particulate/powder

Details on test material:

Product commercial name is ColaFax CPE

Specific details on test material used for the study:

1-Hexadecanol, 1-(dihydrogen phosphate), (ColaFax CPE),
100% Active; Iot Number:64252F18 (100%)

Test animals / tissue source

Species:

human

Strain:

other: stratified human keratinocytes

Test system

Vehicle:

unchanged (no vehicle)

Controls:

yes, concurrent positive control

yes, concurrent negative control

Amount / concentration applied:

50 micrograms

Duration of treatment / exposure:

The tissues were incubated at standard culture conditions for 6 hours +/- 15 minutes.

Duration of post- treatment incubation (in vitro):

At the end of the Post-Soak immersion, each insert was removed from the Assay Medium, the medium was decanted offthe tissue, and the insert was blotted on absorbent material, and transfsned to the appropriate weli of the preJabeled Gwell plate containing I ml of warm Assay Medium. The tissues were incubated for 18 +/- 0.25 hours at standard culture conditions (Post-treatment Incubation).

Number of animals or in vitro replicates:

Duplicates

Details on study design:

*The EpiocularrM human cell construct (MatTek Corporation) is used in the assay. The use of EpiOcular cultures offers features appropriate for a model of ocular irritation. First, the model is composed of stratified human keratinocytes in a three-dimensional structure. Next, test materials can be applied topically to the model so that water insoluble materials may be tested . . . The toxicity of the test article (and thus the ocular initation potential) is evaluated by the relative
viability of the treated tissues relative to the negative control-treated tissues. Viability is determined by the NAD(P)H-dependent microsomal Enzyme reduction of MTT (and to a lesser extent, by the succinate dehydrogenase reduction of MTT) in control and test article-treated cultures."l

Results and discussion

In vitro

Results

Results 1

Irritation parameter:

other: % viability

Run / experiment:

1

Value:

2

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Results 2

Irritation parameter:

other: % viability

Run / experiment:

2

Value:

2.2

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Other effects / acceptance of results:

As per MatTek the assay meets the negative control criteria if the mean OD-570 for the negative control tissues is > 0.8 and < 2.5. The value is 1.764 and it meets the acceptance criteria.
As per MatTek and OECD 492,the assay meets the positive control criteria if the mean viability of the positive control tissues expressed as the percent of the negative control tissues is < 50%. The value is 47.3 and it meets the acceptance criteria
As per MatTek and OECD 492, the assay meets the acceptance criteria if the difference of viability between the two relating tissues of a single chemical is < 20% in the same run. The diflerences for all articles are below 20% and all meet the acceptance criteria.

Any other information on results incl. tables

The test chemical is identified as not requiring classification and labelling according to UN GHS (No Category) if the mean percent tissue viability after exposure and post-exposure incubation is more than (>) 60%. In this case no further testing in other test methods is required.

The test chemical is identified as potentially requiring classification and labelling according to UN GHS (Category 2 or Category 1) if the mean percent tissue viability after exposure and post exposure incubation is less than or equal (<=) to 60%. When the final mean percent tissue viability is less than or equal (<=) to 60% further testing with other test methods will be required because the Epiocular EIT shows a certain number of false positive results and cannot resolve between UN GHS Categories I and 2.

Applicant's summary and conclusion

Interpretation of results:

study cannot be used for classification

Conclusions:

Under the conditions of this test, with a mean tissue viability of 2.1%, the test article, 1-Hexadecanol, 1-(dihydrogen phosphate), (ColaFax CPE), 100% Active;
is considered an irritant. However, the actual classification i.e. Eye irritant Cat 2 or eye damage Cat 1 cannot be distinguished precisely.
It is highly likely though that the very low result compared with the positive control (methyl acetate = eye irritant Cat 2) i.e. 2.1% verses 47.3%, that from a precautionary approach, this substance should be classified as Eye Damage Cat 1