Reaction mass of hexadecyl dihydrogen phosphate and cetyl alcohol (mono- C16 PSE and C16-OH)

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

other:

Cross-reference

Cross-reference 1

Reason / purpose for cross-reference:

data waiving: supporting information

Reference

Based on the available weight of evidence from studies on the main constituents, the test substance can be considered to have a low acute oral toxicity, with LD50 values exceeding 2000 mg/kg bw,

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

2 000 mg/kg bw

Endpoint conclusion:

no study available

Endpoint conclusion:

no study available

Oral:

In absence of acute oral toxicity study with the test substance, the endpoint has been assessed based on studies for substances representative of the two main constituents, which can be categorised as phosphate esters (PSE) and alcohol. The results are presented below:

Constituent 1: PSE - read across study:

Study 1:A study was conducted to determine the acute oral toxicity of the read across substance, mono- and di- C16 PSE, K+ (purity: ca. 85%), according to the OECD Guideline 401, standard acute method, in compliance with GLP. Five male and 5 female Fü-albino SPF rats were randomly selected for an acute oral toxicity study. Fasted rats were given a single dose of the test substance suspended in SSV (Standard Suspended Vehicle) by gavage at a dose level of 5000 mg/kg bw. They were observed for 15 d for toxic signs, mortality and body weight changes. All rats were examined for gross lesions. No compound-related deaths occurred. No compound-related incompatibility reactions were observed. No compound-related effect on body weight development appeared. No compound-related gross or microscopic lesions were observed. The LD50 was determined at >5000 mg/kg bw (i.e., equivalent to >4250 mg a.i./kg bw) (Bremer, 1987).

Study 2:A study was conducted to determine the acute toxicity of the read across substance, di- C16 PSE (purity: 100%), according to the notification no. 118 of the Pharmaceuticals Affairs Bureau, 15 Feb 1984, Toxicity Test Guideline (similar to OECD guideline 401). Groups of fasted, 4 to 6 weeks old CFY (Sprague-Dawley origin) rats, 10/sex were given a single oral dose of test substance in distilled water at doses of 0 (control) and 16 g/kg bw and observed for 14 d. No mortality occurred. Piloerection was observed in all animals in the treated group, however, the animals had recovered on Day 3. No effects on body weight were observed. Terminal necropsy findings were found to be normal. Under the study conditions, the oral LD50 in rats for test substance was determined to be >16000 mg/kg bw (Huntingdon, 1985).

Constituent 2: Alcohol:

A study was conducted to determine the acute oral toxicity of hexadecan-1-ol (purity: >95%), according to the OECD Guideline 401, in compliance with GLP. Five male and five female fasted Sprague-Dawley CD rats were exposed to the 2000 mg/kg bw (based on range finding test) of test substance in arachis oil by oral gavage. The rats were observed for clinical signs of toxicity and mortality 30 minutes, 1, 2 and 4 h after dosing and thereafter daily throughout the observation period. Body weights were recorded prior to dosing on Day 0 and then at 7 and 14 d. All animals were subject to gross pathological examination at the end of the observation period. No compound-related deaths occurred. No compound-related target organ toxicity were observed. No clinical signs of systemic toxicity were observed. All animals showed the expected body weight gain over the observation period. No compound-related gross or microscopic lesions were observed. Under the study conditions, the LD50 for the read across substance was determined to be >2000 mg/kg bw (i.e., >1900 mg a.i./kg bw) (OECD SIDS, 2006).

Overall, the test substance can be considered to have a low acute oral toxicity, with LD50 values for its main constituents >2000 mg/kg bw..

Dermal:

As per Annex VIII (8.5.3), the acute dermal toxicity testing is not needed as the substance does not meet the criteria for classification for acute toxicity and STOT SE for the oral route (based on read across studies). This is also supported by the absence of any systemic effects in thein vivoskin sensitisation study available with the read across substance, ‘mono- and di- C16 PSE, K+ and H3PO4’. Moreover, given the physico-chemical properties of the test substance, the dermal LD50 value is less likely (due to lower absorption potential of dermal route) to be lower than oral LD50 or the oral doses showing clinical signs. Hence, testing via dermal route will less likely result in any additional hazard identification and testing is therefore considered unnecessary. No systemic toxicity was observed in thein vivoskin sensitisation study available with the read across substance.

Inhalation:

The substance is a solid powder (particle size exceeding 2000 µm) with a low vapour pressure at room temperature. Due to its physical state and physical chemical properties it is unlikely that this substance will form inhalable dust, mist or fumes during normal processing and use conditions. In case inhalable forms of the substance are created under particular conditions (e. g. spraying, elevated temperature/pressure), appropriate risk management measures such as closed systems, exhaust ventilation or wearing of respirators are implemented to control exposure. Under such conditions, the risk to humans following inhalation exposure can be considered minimal and further testing

Overall, based on the available weight of evidence from studies on the main constituents, the test substance, 'mono- C16 PSE + C16-OH', does not warrant classification for acute toxicity according to EU CLP (Regulation 1272/2008/EC).

Cross-reference 2

Reason / purpose for cross-reference:

data waiving: supporting information

Reference

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Study period:

From May 25, 2005 to June 13, 2005

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

KL2 due to RA

Justification for type of information:

Refer to section 13 of IUCLID for details on the read-across justification. The study with the read across substance is considered sufficient to fulfil the information requirements as further explained in the provided endpoint summary.

Reason / purpose for cross-reference:

read-across source

Qualifier:

according to guideline

Guideline:

OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.2600 (Skin Sensitisation)

Deviations:

no

GLP compliance:

yes

Type of study:

mouse local lymph node assay (LLNA)

Species:

mouse

Strain:

CBA:J

Sex:

female

Details on test animals and environmental conditions:

Source: Jackson Laboratories
Acclimation: 5 days
Number of animals: 37 females (nulliparous and non-pregnant)
Body weight: 16 - 21g
Body weight variation was within +/- 20% of the sex mean.
Environmental controls for the animal room were set to maintain 18 to 24°C, a relative humidity of 40 to 70%, at least 10 air changes/hour, and a 12-hour light/12-hour dark cycle.
Diet: Fresh PMI (Diet #5001)
Water: free access to tap water.

Vehicle:

other: Ultrapure liquid petrolatum

Concentration:

0, 2.5, 5, 10 and 25% w/w

No. of animals per dose:

5

Details on study design:

The test 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 test 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

Positive control substance(s):

hexyl cinnamic aldehyde (CAS No 101-86-0)

Statistics:

SI

Positive control results:

The SI value calculated for the positive control was 9.6 and ear swelling was observed in this group.

Key result

Parameter:

SI

Value:

ca. 0.9

Variability:

+/- 0.7

Test group / Remarks:

2.5%

Key result

Parameter:

SI

Value:

ca. 0.9

Variability:

+/- 0.6

Test group / Remarks:

5%

Key result

Parameter:

SI

Value:

ca. 0.7

Variability:

+/- 0.3

Test group / Remarks:

10%

Key result

Parameter:

SI

Value:

ca. 0.3

Variability:

+/- 0.1

Test group / Remarks:

25%

Cellular proliferation data / Observations:

- 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.

Interpretation of results:

other: not classified based on EU CLP criteria

Conclusions:

Based on the results of the read across study, the test substance, is considered to be non-sensitiser to the skin.

Executive summary:

A study was conducted to determine the skin sensitisation potential of the read across substance, 'mono- and di- C16 PSE, K+ 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). Based on the results of the read across study, the test substance, 'mono- C16 PSE and C16 -OH' is considered to be non-sensitiser to the skin.