Phosphoric acid, hexadecyl phosphate esters, potassium salts with cetostearyl alcohol

Endpoint summary

Description of key information

Based on the available weight of evidence information from studies for substances representative of the main constituents, the test substance, ‘mono- and di- C16 PSE, K+ and C16 -18-OH' is considered to be non-sensitising to skin.

Key value for chemical safety assessment

Skin sensitisation

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

In absence of skin sensitisation study with the test substance, the endpoint has been assessed based on studies for substances representative of the main constituents, which can be categorised as phosphate esters (PSE; i.e., mono- and di- C16 PSE, K+) and alcohol (i.e., alcohols, C16-18). The results are presented below:

Constituent: PSE - read across study

A study was conducted to determine the skin sensitisation potential of the read across substance, 'mono- and di- C16 PSE and H3PO4' (98.5%) according to OECD Guideline 429 and US EPA OPPTS 870.2600 (LLNA), in compliance with GLP. The read across substance concentrations selected for the main study were based on the results of a pre-screen test. In the main study, four experimental groups of five female CBA/J mice were treated with read across substance concentrations of 2.5, 5, 10 or 25% w/w for three consecutive days, by topical application on the ears. Five vehicle control animals were similarly treated, but with the vehicle alone (Liquid petrolatum). A positive control group with a-hexylcinnamaldehyde (HCA - 50%) was also included in the experiment. Five days after the last exposure, all animals were injected with 5-bromo-2'-deoxy-uridine (BrdU) and the draining (auricular) lymph nodes were then isolated and pooled for each animal. Cells were fixed using 70% ethanol and used for the measurement of the cell number and the BrdU determination (percentage of proliferating cells in "S" phase). Flow cytometry was conducted for analysis and stimulation index (SI) was recorded. Mortality/viability, body weights, clinical signs, ear size and irritation (and other local effects) were recorded as well. SI values were similar among the control and test groups and were below 3. Three concentrations (i.e.2.5, 5 and 25%) induced ear swelling. No mortality occurred and no clinical signs of systemic toxicity were observed in the animals of the main study. Body weights and body weight gain of experimental animals remained in the same range as controls over the study period (MBRL, 2005).

 

Constituent: Alcohol:

A study was conducted to determine the skin sensitisation potential of the test substance, 'Alcohols, C16-18' (>=90%), using Magnusson & Kligman maximisation test, according to OECD Guideline 406 and EU Method B.6. The test was performed in 40 (20 test and 20 control) female guinea pigs. For the induction phase, on Day 1, 2 pairs of intradermal injections (0.1 mL/site) [Injection 1: a 1:1 mixture (w/w) Freud’s Complete Adjuvant (FCA), Injection 2: test substance in olive oil in a 1:1 mixture (w/w) with FCA (final concentration is 5% test substance)] were given. No details about positive control substance were reported. On Day 8, 0.5 mL 5% test substance in Vaseline was applied to skin area under occlusive conditions for 48 h. The degree of erythema and edema was evaluated directly after cleaning the skin area with water (Day 10). Similar procedure was followed for control substance (Olive oil or Vaseline). For challenge phase, on Day 21, 0.5 mL of 25% test substance in Vaseline/ethanol or control substance was applied to one flank of the animals and evaluation was made 24 and 48 h after the challenge ended. No erythema or edema was reported in any animal groups. After 48 and 72 h after the challenge, no sensitisation was observed in the treated animals. Under the study conditions, the test substance was determined to be non-sensitising to the skin (OECD SIDS, 2006).

Overall, based on the available weight of evidence information from studies for substances representative of the main constituents, the test substance, ‘mono- and di- C16 PSE, K+ and C16 -18-OH' is considered to be non-sensitising to skin.

 

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

Based on the available weight of evidence information from studies for substances representative of the main constituents, the test substance, ‘mono- and di- C16 PSE, K+ and C16 -18-OH' does not warrant classification for skin sensitisation according to EU CLP criteria (Regulation 1272/2008/EC).