Hydrocarbons, C15-C19, n-alkanes, isoalkanes,

Endpoint summary

Description of key information

An in vitro skin irritation was conducted on Hydrocarbons, C15-C19, n-alkanes, isoalkanes, <2% aromatics according to OECD TG 439 and in compliance with GLP (WIL Research, 2014a). The mean relative skin viability of the test substance was 91%, so it was concluded that the test substance is not irritant under the conditions of this test.

A bovine corneal opacity in vitro assay (BCOP test) was conducted on Hydrocarbons, C15-C19, n-alkanes, isoalkanes, <2% aromatics according to OECD TG 437 and in compliance with GLP (WIL Research, 2014b). The endpoints assessed in this assay are opacity and permeability; negative and positive controls gave expected results. The test substance did not indicate an irritancy potential based on either the opacity or permeability endpoints.

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Endpoint:

skin irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

21-Jul-2014 to 28-Jul-2014

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)

Deviations:

no

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Vehicle:

unchanged (no vehicle)

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 25 µl

NEGATIVE CONTOL:
- Amount(s) applied (volume or weight with unit): 10 µl Phosphate buffered saline

POSITIVE CONTROL
- Amount(s) applied (volume or weight with unit): 10 µl
- Concentration (if solution): 5% (aq) Sodium dodecyl sulphate

Duration of treatment / exposure:

Exposure:15 minutes
Post incubation period: 42 hours

Details on study design:

TEST SITE
- Area of exposure: human epidermis model
- % coverage: 0.38 cm2

REMOVAL OF TEST SUBSTANCE
- Washing (if done): phosphate buffered saline
- Time after start of exposure: 15 minutes

POST INCUBATION PERIOD
- 42 hours

SCORING SYSTEM:
- After a 42 hour incubation period, determination of the cytotoxic (irritancy) effect was performed. Cytotoxicity is expressed as the reduction of mitochondrial dehydrogenase activity measured by formazan production from MTT at the end of the treatment. Cell viability was calculated for each tissue as a percentage of the mean of the negative control tissues.

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

15-minute exposure

Value:

94

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Remarks:

The absolute mean of the negative control was slightly below the historical control data range. It was concluded that the deviation had no effect on the study results.

Positive controls validity:

valid

Remarks:

A clear toxic effect was observed with the positive control. The low absolute mean OD570 value of the positive control, which was in the lower range of the historical control data range, resulted in a good measurement window.

Remarks on result:

no indication of irritation

Interpretation of results:

GHS criteria not met

Conclusions:

An in vitro skin irritation study was also conducted with Hydrocarbons, C15-C19, n-alkanes, isoalkanes, <2% aromatics (GS270) in accordance with OECD Test Guideline 439 and in compliance with GLP. The in vitro assay did not indicate any skin irritation potential.

Executive summary:

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 Hydrocarbons, C15-C19, n-alkanes, isoalkanes, <2% aromatics compared to the negative control tissues was 94%. Since the mean relative tissue viability for the test substance was above 50% after 15 minutes treatment the test substance is considered to be non-irritant.

 

The positive control had a mean cell viability of 21% after 15 minutes exposure. The absolute mean OD570 (optical density at 570 nm) of the negative control tissues was slightly below laboratory historical control data range. The standard deviation value of the percentage viability of three tissues treated identically was less than 7%, indicating that the test system functioned properly.

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:

15-Jul-2014

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)

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)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Vehicle:

unchanged (no vehicle)

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 750 µl per cornea

NEGATIVE CONTROL
- Amount(s) applied (volume or weight with unit): 750 µl of physiological saline per cornea

POSITIVE CONTROL
Amount(s) applied (volume or weight with unit): 750 µl per cornea
Concentration (if solution): 10% (w/v) Benzalkonium Chloride

Duration of treatment / exposure:

10 minutes

Details on study design:

TEST SITE
- Isolated bovine cornea

REMOVAL OF TEST SUBSTANCE
- Washing (if done): yes
- Time after start of exposure: 10 minutes

SCORING SYSTEM:
- After exposure the cornea was thoroughly rinsed to remove the test substance and incubated for 2 hours with fresh medium followed by opacity measurement and the permeability of the corneas was determined after a 90 minutes incubation period with sodium fluorescein.

- The mean opacity and mean permeability values (OD490) were used for each treatment group to calculate an in vitro score:

In vitro irritancy score (IVIS) = mean opacity value + (15 x mean OD490 value).


TOOL USED TO ASSESS SCORE:
- opacitymeter and microplate reader

DATA EVALUATION:
In vitro score range UN GHS
≤ 3 No Category
> 3; ≤ 55 No prediction can be made
>55 Category 1

Irritation parameter:

in vitro irritation score

Run / experiment:

10-minute exposure

Value:

0.1

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

no indication of irritation

Interpretation of results:

GHS criteria not met

Conclusions:

An in vitro eye irritation study was also conducted with Hydrocarbons, C15-C19, n-alkanes, isoalkanes, <2% aromatics (GS270), in accordance with OECD test guideline 437 and in compliance with GLP. The BCOP test did not indicate an irritancy potential based on either the opacity or permeability endpoints.

Executive summary:

The negative control responses of the opacity and permeability values were less than the upper limits of the laboratory historical range indicating that the negative control did not induce irritancy on the corneas.The mean in vitro irritancy score of the positive control (10% (w/v) Benzalkonium Chloride) was 139 and within the historical positive control data range. It was therefore concluded that the test conditions were adequate and that the test system functioned properly.

The test substance did not induce ocular irritation through both endpoints, resulting in a mean in vitro irritancy score of 0.1 after 10 minutes of treatment.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Hydrocarbons, C15-C19, n-alkanes, isoalkanes, <2% aromatics has been tested in an in vitro assay conducted according to OECD TG 439 and in compliance with GLP (WIL Research, 2014a). The test substance was applied to a human three-dimensional epidermal model, EPISKIN-SM^TM, for 15 minutes. The positive control had mean relative skin viability (the measure of irritancy) of 21%, and an optical density at 570 nm very slightly below the historical control data range. The mean relative skin viability of the test substance was 91%, so it was concluded that the test substance is not irritant under the conditions of this test.

Hydrocarbons, C15-C19, n-alkanes, isoalkanes, <2% aromatics has been tested in a bovine corneal opacity in vitro assay (BCOP test) conducted according to OECD TG 437 and in compliance with GLP (WIL Research, 2014b). The endpoints assessed in this assay are opacity and permeability; negative and positive controls gave expected results. The test substance did not induce ocular irritation as assessed by both endpoints.

Repeated dermal contact with petroleum-derived hydrocarbons causes skin dryness and cracking, and Hydrocarbons, C15-C19, n-alkanes, isoalkanes, <2% aromatics was formerly classified for skin defatting from repeated skin contact: EUH066, based on precaution. To establish whether this classification was justified, a study has been conducted with volunteers to investigate the hydrating efficacy and the skin barrier integrity efficacy of a number of substances in a double-blind, randomised study. The test substances included Hydrocarbons, C15-C19, n-alkanes, isoalkanes, <2% aromatics.

Skin hydration was assessed by measurement of skin capacitance compared with a placebo (Span 80 (0.65%) and Tween 80 (0.20%) in water), a negative control (water), and a positive control. The positive control was an aqueous solution of glycerine at 85%, glycerine is a known moisturiser and not classified for skin defatting from repeated skin contact.

Skin barrier integrity efficacy was assessed by measurement of the skin transepidermal water loss (TEWL) compared with a placebo (Span 80 (0.65%) and Tween 80 (0.20%) in water) and a negative control (water).

Healthy adult volunteers were split into four groups. Each subject received a single application of 2 µl/ cm² of five test substances, a placebo, a negative control and, for the skin capacitance measurement, a positive control. Test and control substances were applied to eight separate sites, four on each forearm, of each volunteer in the group. Each group had a different set of test substances.

Ten test substances were tested at two different concentrations, 5% and 100%.

The skin hydration measurements were performed at each test site, in triplicate, before application of the test and control substances, and at 2 hours, 4 hours, 8 hours and 24 hours after application.

The skin transepidermal water loss (TEWL) measurements were performed at the same test sites and time intervals as the skin hydration measurements.

Application of Hydrocarbons, C15-C19, n-alkanes, isoalkanes, <2% aromatics (Shell GTL Solvent GS270) resulted in a statistically significant increase in the skin hydration relative to the placebo up to 2 hours after application at a concentration of 100%. At 5%, skin hydration was unaffected".

Application of Hydrocarbons, C15-C19, n-alkanes, isoalkanes, <2% aromatics (Shell GTL Solvent GS270) did not affect the TEWL relative to the placebo at concentrations of 5% and 100%, indicating no effect on the skin barrier condition.

These results indicate that, after a single application, Hydrocarbons, C15-C19, n-alkanes, isoalkanes, <2% aromatics is effective as a skin moisturiser and does not affect the skin barrier. Based on these results, it is concluded that the test substance does not require classification for skin defatting from repeated skin contact.

References:

Kottner J., Vogt A., Lichterfeld A., Blume-Peytavi U. (2015) Transepidermal Water Loss in Young and Aged Healthy Humans. In: Farage M., Miller K., Maibach H. (eds) Textbook of Aging Skin. Springer, Berlin, Heidelberg.https://doi.org/10.1007/978-3-642-27814-3_127-1

Kovács, A., Péter-Héderi, D., Perei, K., Budai-Szűcs, M., Léber, A., Gácsi, A., ... & Berkó, S. (2020). Effects of Formulation Excipients on Skin Barrier Function in Creams Used in Pediatric Care. Pharmaceutics, 12(8), 729.

Lodén, M., Andersson, A. C., Anderson, C., Bergbrant, I. M., Frodin, T., Ohman, H., ... & Lindberg, M. (2002). A double-blind study comparing the effect of glycerin and urea on dry, eczematous skin in atopic patients. Acta Dermato Venereologica, 82(1), 45-47.

Milani, M., & Sparavigna, A. (2017). The 24-hour skin hydration and barrier function effects of a hyaluronic 1%, glycerin 5%, and Centella asiatica stem cells extract moisturizing fluid: an intra-subject, randomized, assessor-blinded study. Clinical, cosmetic and investigational dermatology, 10, 311.

Qassem, M., & Kyriacou, P. (2019). Review of modern techniques for the assessment of skin hydration. Cosmetics, 6(1), 19.

Justification for classification or non-classification

As all reliable studies show no irritation effect or irritation effects slight enough not to classify the test materials, Hydrocarbons, C15-C19, n-alkanes, isoalkanes, <2% aromatics does not need to be classified as irritant for skin and eye according to the criteria of Annex VI of Regulation (EC) No 1272/2008.