Hydrocarbon waxes (petroleum), oxidized, Me esters

Endpoint summary

Description of key information

The acute oral median lethal dose (LD50) of the test item in the female Wistar strain rat was found to be > 2000 mg/kg bw using the fixed dose method (OECD 420 and EU Method B.1 bis).

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records

Reference

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

15 February 2017 to 06 March 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 420 (Acute Oral Toxicity - Fixed Dose Method)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.1 bis (Acute Oral Toxicity - Fixed Dose Procedure)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test type:

fixed dose procedure

Limit test:

yes

Species:

rat

Strain:

Wistar

Remarks:

RccHan:WIST

Sex:

female

Details on test animals or test system and environmental conditions:

ANIMAL INFORMATION
- Female Wistar (RccHan:WIST) strain rats were supplied by Envigo RMS (UK) Limited, Oxon, UK.
- On receipt the animals were randomly allocated to cages.
- The female animals were nulliparous and non-pregnant.
- After an acclimatisation period of at least five days, animals were selected at random and given a number unique within the study by indelible ink-marking on the tail and a number written on the cage card.
- At the start of the study the animals were 8 to 12 weeks of age.
- Body weight variation did not exceed ± 20 % of the mean body weight at the start of treatment.

ANIMAL CARE AND HUSBANDRY
- Animals were housed in groups of up to four in suspended solid-floor polypropylene cages furnished with woodflakes.
- With the exception of an overnight fast immediately before dosing, and for approximately 3 to 4 hours after dosing, free access to mains drinking water and food (2014C Teklad Global Rodent diet supplied by Envigo RMS (UK) Limited, Oxon, UK) was allowed throughout the study.
- Diet and drinking water were routinely analysed and were considered not to contain any contaminants that would reasonably be expected to affect the purpose or integrity of the study.
- Temperature and relative humidity were set to achieve limits of 19 to 25 °C and 30 to 70 % respectively.
- Rate of air exchange was at least 15 changes per hour.
- Lighting was controlled by a time switch to give 12 hours continuous light and 12 hours darkness.
- Animals were provided with environmental enrichment items that were considered not to contain any contaminant of a level that might have affected the purpose or integrity of the study.

Route of administration:

oral: gavage

Vehicle:

arachis oil

Details on oral exposure:

TEST ITEM PREPARATION AND ANALYSIS
- The test item was freshly prepared, as required, as a suspension in arachis oil. Arachis oil BP was used because the test item did not dissolve/suspend in distilled water.
- The test item was formulated within 2 hours of being applied to the test system. It is assumed that the formulation was stable for this duration.
- No analysis was conducted to determine the homogeneity, concentration or stability of the test item formulation. This is an exception with regard to GLP and was reflected in the GLP compliance statement.

EXPOSURE TO TEST ITEM
- All animals were dosed once only by gavage, using a metal cannula attached to a graduated syringe.
- The volume administered to each animal was calculated according to the fasted body weight at the time of dosing.
- Treatment of animals was sequential.
- Sufficient time was allowed between each dose group to confirm the survival of the previously dosed animals.
- Clinical observations were made 0.5, 1, 2 and 4 hours after dosing and then daily for 14 days.
- Morbidity and mortality checks were made twice daily (early and late) during normal working days and once daily at weekends and public holidays.
- Individual body weights were recorded on Day 0 (the day of dosing) and on Days 7 and 14.
- At the end of the observation period animals were killed by cervical dislocation.
- All animals were subjected to gross necropsy consisting of an external examination and opening of the abdominal and thoracic cavities. The appearance of any macroscopic abnormalities was recorded. No tissues were retained.

Doses:

2000 mg/kg bw

No. of animals per sex per dose:

Five

Control animals:

no

Details on study design:

STUDY DESIGN
- In the absence of data regarding the toxicity of the test item, 2000 mg/kg was chosen as the starting dose (see Annex 2, attached).
- A single female animal was treated at a dose level of 2000 mg/kg (concentration 200 mg/mL; dose volume 10 mL/kg).
- In the absence of toxicity at a dose level of 2000 mg/kg, an additional four animals were treated at a dose level of 2000 mg/kg (concentration 200 mg/mL; dose volume 10 mL/kg).

DATA EVALUATION
- The test item was evaluated according to Annex 3 of the OECD Guidelines for Testing of Chemicals No 420 “Acute Oral Toxicity – Fixed Dose Method” (adopted 17 December 2001) as shown in the flow chart in Annex 3 (attached).
- Evaluation of data included identification of the number of animals that died during the study (or that were killed for humane reasons) plus determination of the nature, severity, onset and duration of toxic effects. If possible, the signs of evident toxicity were described. Evident toxicity refers to the toxic effects of sufficient severity that administration of the next higher dose level could result in development of severe signs of toxicity and probable mortality. Effects on body weights and abnormalities noted at necropsy were also identified.

MAJOR COMPUTERISED SYSTEMS
- Delta Controls: ORCAview

Statistics:

STATISTICS
- Using the mortality data obtained, an estimate of the acute oral median lethal dose (LD50) of the test item was made.

Key result

Sex:

female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

- Individual mortality data are given in Appendix 1 (attached).
- No unscheduled animal deaths took place.

Clinical signs:

other: - Individual clinical observations are presented in Appendix 1 (attached). - No signs of systemic toxicity were noted during the observation period.

Gross pathology:

- Individual necropsy findings are given in Appendix 3 (attached).
- No abnormalities were noted at necropsy.

Interpretation of results:

GHS criteria not met

Conclusions:

The acute oral median lethal dose (LD50) of the test item in the female Wistar strain rat was found to be > 2000 mg/kg bw.

Executive summary:

GUIDELINE

The study was performed to assess acute oral toxicity of the test item in the Wistar strain rat in compliance with the OECD Guideline for Testing of Chemicals No 420 “Acute Oral Toxicity – Fixed Dose Method” (2001) and Method B.1 bis Acute Toxicity (Oral) of Commission Regulation (EC) No 440/2008.

 

METHODS

Following a sighting test at 2000 mg/kg, an additional four fasted female animals were given a single oral dose of test item, as a suspension in arachis oil BP, at a dose level of 2000 mg/kg body weight. Clinical signs and body weight development were monitored during the study. All animals were subjected to gross necropsy.

 

RESULTS

No unscheduled animal deaths took place during the study and no signs of systemic toxicity were reported. All animals showed expected gains in body weight and no abnormalities were noted at necropsy.

 

CONCLUSION

The acute oral median lethal dose (LD50) of the test item in the female Wistar strain rat was found to be > 2000 mg/kg bw.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Acute toxicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no study available

Acute toxicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Oral route

The key study was performed to assess acute oral toxicity of the test item in the Wistar strain rat in compliance with the OECD Guideline for Testing of Chemicals No 420 “Acute Oral Toxicity – Fixed Dose Method” (2001) and Method B.1 bis Acute Toxicity (Oral) of Commission Regulation (EC) No 440/2008.

 

Following a sighting test at 2000 mg/kg, an additional four fasted female animals were given a single oral dose of test item, as a suspension in arachis oil BP, at a dose level of 2000 mg/kg body weight. Clinical signs and body weight development were monitored during the study. All animals were subjected to gross necropsy.

No unscheduled animal deaths took place during the study and no signs of systemic toxicity were reported. All animals showed expected gains in body weight and no abnormalities were noted at necropsy. The acute oral median lethal dose (LD50) of the test item in the female Wistar strain rat was found to be > 2000 mg/kg bw.

Inhalation route

The substance decomposes from approximately 183 °C at 98 kPa and the vapour pressure has been determined to be 1.91 Pa at 25 °C. It is therefore expected that inhalation exposure will be low under general use conditions at ambient temperature. Lack of systemic toxicity when the substance is administered via the oral route suggests that determined vapour pressures of 13.0 Pa at 82 °C and 18.8 Pa at 88°C also give no cause for concern. The inhalation route is therefore not the most applicable method of investigating acute toxicity.

Dermal route

The substance is a paste that is non-toxic via the oral route under acute conditions (LD50 > 2000 mg/kg) and repeated exposure of the skin is not expected under normal condition of use. In addition, the test material has been determined to have a low vapour pressure (1.91 Pa at 25 °C) and high onset boiling point range (decomposition from approximately 183 °C at 101 kPa). These data indicate that the potential for dermal absorption after exposure to vapour is low under general use conditions at ambient temperature. Furthermore, the substance is a UVCB with a relatively high molecular weight, is highly insoluble in water (4.34 x 10E-03 gTOC/L at 20.0 ± 0.5 °C) and has a Log10 Kow value of > 10.0. Consequently, and in accordance with ECHA Guidance on Information Requirements and Chemical Safety Assessment Chapter R.7c: Endpoint specific guidance (Version 3.0; June 2017), the substance is considered insufficiently soluble to partition from the stratum corneum into the epidermis and the majority of UVCB constituents are likely to be too large to favour dermal absorption (molecular weight > 100 g/moL and log10 Pow > 4). Investigation of acute toxicity via the dermal route is therefore contraindicated.

Justification for classification or non-classification

The acute oral median lethal dose (LD50) of the test item in the female Wistar strain rat was found to be > 2000 mg/kg bw and classification for acute oral toxicity is not required under the terms of Regulation (EC) No 1272/2008.