Docosane

Endpoint summary

Description of key information

No acute oral, dermal, or inhalation toxicity data is available for docosane. However, key oral toxicity and supporting dermal and inhalation toxicity data is available from structurally related substances, C18-C50 branched, cyclic and linear hydrocarbons – Distillates (CAS# 848301-69-9) and C8-C26 branched and linear hydrocarbons – Distillates (CAS# 848301-67-7) and is presented below.

1) Acute oral toxicity: The acute oral median lethal dose (LD₅₀) of C18-C50 branched, cyclic and linear hydrocarbons – Distillates (CAS# 848301-69-9) in the female Sprague-Dawley CD strain rat was estimated to be greater than 5000 mg/kg bodyweight.

2) Acute inhalation and dermal toxicity: Based on lack of skin irritation and systemic effects in a read across skin irritation study, docosane is not considered to be acutely harmful in contact with skin. Moreover, the substance is unlikely to form aerosols or particles of inhalable size. Therefore it is considered justifiable not to conduct these studies.

Supporting data on a related substance C8-C26 branched and linear hydrocarbons – Distillates (CAS# 848301-67-7) indicate the low dermal and inhalation toxicity:

a) Acute inhalation toxicity study (Shell, 2013a), conducted according to OECD 436 and GLP, reported an acute inhalation median lethal concentration (4 hr LC₅₀) of Distillates (Fischer-Tropsch), C8-26-branched and linear, in the RccHanTM: WIST strain rat >5 mg/L.

b) Acute dermal toxicity study (Shell, 2015a), conducted according to OECD 402 (Acute Dermal Toxicity) and GLP, reported an LD₅₀ in male and female rats >2000 mg/Kg bw.

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:

The study was performed between 23 October 2006 and 13 November 2006.

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study conducted to GLP and in compliance with agreed protocols, with no or minor deviations from standard test guidelines and/or minor methodological deficiencies, which do not effect the quality of the relevant results.

Justification for type of information:

A discussion and report on the read across strategy is given as an attachment in IUCLID Section 13.

Reason / purpose for cross-reference:

read-across: supporting information

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)

Remarks:

Date of inspection: 30/8/2005. Date of signature: 21/11/2005

Test type:

fixed dose procedure

Limit test:

yes

Species:

rat

Strain:

Sprague-Dawley

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Age at study initiation: Eight to twelve weeks of age.
- Weight at study initiation: 205-225 g at Day 0.
- Fasting period before study: Overnight fast immediately before dosing and for approximately three to four hours after dosing.
- Housing: The animals were housed in groups of up to four in suspended solid-floor polypropylene cages furnished with woodflakes.
- Diet (e.g. ad libitum): Free access to food (certified rate and mouse diet) was allowed throughout the study.
- Water (e.g. ad libitum): Free access to mains drinking water was allowed throughout the study.
- Acclimation period: At least five days.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): The temperature was set to achieve limits of 19 to 25°C.
- Humidity (%): The relative humidity was set to achieve limits of 30 to 70%.
- Air changes (per hr): At least fifteen changes per hour.
- Photoperiod (hrs dark / hrs light): Lighting was controlled by a time switch to give twelve hours continuous light and twelve hours darkness.

Route of administration:

oral: gavage

Vehicle:

unchanged (no vehicle)

Details on oral exposure:

MAXIMUM DOSE VOLUME APPLIED: 6.20 ml/kg

DOSAGE PREPARATION (if unusual):
For the purpose of the study the test material was used as supplied. The specific gravity was determined and used to calculate the appropriate dose volume for the required dose level.

Doses:

5000 mg/kg

No. of animals per sex per dose:

A total of 5 female animals at a dose level of 5000 mg/kg.

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days.
- Frequency of observations and weighing:
Clinical observations were made 1/2, 1, 2 and 4 hours after dosing and subsequently once daily for fourteen days. Morbidity and mortality checks were made twice daily.
Individual bodyweights were recorded on day (day of dosing) and on days 7 and 14.
- Necropsy of survivors performed: All animals were subjected to gross necropsy. This consisted of an external examination and opening of the abdominal and thoracic cavities. The appearance of any macroscopic abnormalities was recorded.

Preliminary study:

There was no death and no signs of systemic toxicity at 5000 mg/kg.
In the absence of toxicity at 5000 mg/kg, an additional group of 4 animals was treated at a dose level of 5000 mg/kg.

Key result

Sex:

female

Dose descriptor:

LD50

Effect level:

> 5 000 mg/kg bw

Based on:

test mat.

Mortality:

There were no deaths.

Clinical signs:

No signs of systemic toxicity were noted.

Body weight:

All animals showed expected gains in bodyweight over the study period.

Gross pathology:

No abnormalities were noted at necropsy.

Interpretation of results:

not classified

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

The acute oral median lethal dose (LD50) of the test material in the female Sprague-Dawley CD strain rat was estimated to be greater than 5000 mg/kg bodyweight.

Executive summary:

Introduction.

The study was performed to assess the acute oral toxicity of the test material 'Distillates (Fischer-Tropsch), heavy C18-50 - branched, cyclic and linear' in the Sprague-Dawley CD strain rat. The method was designed to meet the requirements of the following:

• OECD Guidelines for Testing of Chemicals No 420 "Acute Oral Toxicity - Fixed Dose Method" (adopted 17 December 2001)

• Method B1 bis Acute Toxicity (Oral) of Commission Directive 2004/73/EC Method.

Method.

Following a preliminary test in which there was no death at a dose level of 5000 mg/kg, an additional four fasted female animals were given a single oral dose of undiluted test material at a dose level of 5000 mg/kg bodyweight. Clinical signs and bodyweight development were monitored during the study. All animals were subjected to gross necropsy.

Mortality.

There were no deaths.

Clinical Observations.

There were no signs of systemic toxicity.

Bodyweight.

All animals showed expected gains in bodyweight.

Necropsy.

No abnormalities were noted at necropsy.

Conclusion.

The acute oral median lethal dose (LD50) of the test material in the female Sprague-Dawley CD strain rat was estimated to be greater than 5000 mg/kg bodyweight (Globally Harmonised Classification System - Unclassified).

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

5 000 mg/kg bw

Quality of whole database:

The study is GLP compliant and has Klimisch score 1.

Acute toxicity: via inhalation route

Link to relevant study records

Reference

Reference 1

Endpoint:

acute toxicity: inhalation

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

other:

Reference 2

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

Experimental Starting Date: 06 January 2014. Experimental Completion Date: 06 februry 2014

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Study on supporting substance (predominantly ≤C26) conducted in compliance with agreed protocols, with no/or minor deviations from standard test guidelines and/or minor methodological deficiencies, which do not affect the quality of the relevant results. Read-across is considered to be reliability 2.

Justification for type of information:

A discussion and report on the read across strategy is given as an attachment in IUCLID Section 13.

Reason / purpose for cross-reference:

read-across: supporting information

Qualifier:

according to guideline

Guideline:

OECD Guideline 436 (Acute Inhalation Toxicity: Acute Toxic Class Method)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test type:

acute toxic class method

Limit test:

no

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

Male and female RccHan™ : WIST strain rats were supplied by Harlan Laboratories UK Ltd, Oxon, UK. On receipt the animals were randomly allocated to cages. After an acclimatization period of at least five days the animals were given a number unique within the study by ear punching and a number written on a color coded cage card. At the start of the study the animals were approximately eight to twelve weeks old and within the weight range of 200g to 350g. The females were nulliparous and non-pregnant.

The animals were housed in groups of up to three by sex in solid-floor polypropylene cages with stainless steel lids, furnished with softwood flakes (Datesand Ltd., Cheshire, UK) and provided with environmental enrichment items: wooden chew blocks and cardboard “fun tunnels” (Datesand Ltd., Cheshire, UK). With the exception of the exposure period, free access to mains drinking water and food (Harlan 2014C Rodent Diet, Harlan Laboratories UK Ltd, Oxon, UK) was allowed throughout the study. The diet, drinking water, bedding and chew blocks are routinely analyzed and are considered not to contain any contaminants that could reasonably be expected to affect the purpose or integrity of the study.

The temperature and relative humidity were set to achieve limits of 19 to 25 C and 30 to 70% respectively. The rate of air exchange was at least fifteen changes per hour and the lighting was controlled by a time switch to give twelve hours continuous light (06:00 to 18:00) and twelve hours darkness. The animals were retained in this accommodation at all times except during the exposure period.

Route of administration:

inhalation: aerosol

Type of inhalation exposure:

nose only

Vehicle:

other: Unchanged (no vehicle)

Details on inhalation exposure:

Atmosphere Generation
The test item was aerosolized using a glass concentric jet nebulizer (Radleys, Saffron Walden, Essex, UK) located at the top of the exposure chamber. The nebulizer was connected to a plastic syringe attached to an infusion pump, which provided a continuous supply of test item under pressure, and to a metered compressed air supply.

Compressed air was supplied by means of an oil free compressor and passed through a water trap and respiratory quality filters before it was introduced to the nebulizer.

The cylindrical exposure chamber had a volume of approximately 30 liters (dimensions: 28 cm diameter x 50 cm high). The concentration within the exposure chamber was controlled by adjusting the rate of the infusion pump. The extract from the exposure chamber passed through a ‘scrubber’ trap and was connected with a high efficiency filter to a metered exhaust system. The chamber was maintained under negative pressure. A diagram of the dynamic (continuous flow) system employed is shown in Figure 1.

Homogeneity of the test atmosphere within the chamber was not specifically determined during this study. Chambers of the same design (ADG Developments Ltd, Hitchin, Herts, UK) have been fully validated and shown to produce evenly distributed atmospheres in the animals’ breathing zone with a wide variety of test items (Green J D et al, 1984).

Prior to the start of the study, test item atmospheres were generated within the exposure chamber. During this characterization period test item input rates were varied to achieve the required atmospheric conditions.


Exposure Procedure
Prior to the day of each exposure each rat was acclimatized (for approximately 2 hours) to a tapered polycarbonate restraining tube. During the exposure period, each rat was individually held in a tapered, polycarbonate restraining tube fitted onto a single tier of the exposure chamber and sealed by means of a rubber ‘O’ ring. Only the nose of each animal was exposed to the test atmosphere.

Following an appropriate equilibration period two groups, each of six rats (three males and three females), were subjected to a single exposure to the test item for a period of four hours. Based on the expected toxicity of the test item, a target concentration of 5.0 mg/L was used for the first exposure. The second concentration was selected after consideration of the results of the first exposure.


Exposure Chamber Temperature and Relative Humidity
The temperature and relative humidity inside the exposure chamber were measured by an electronic thermometer/humidity meter (Hanna Instruments Ltd, Beds., UK) located in a vacant port in the animals’ breathing zone of the chamber and recorded every thirty minutes throughout the four-hour exposure period.

Exposure Chamber Oxygen Concentration
Oxygen levels within the exposure chamber were measured by an electronic oxygen analyzer (Servomex (UK) Ltd, Crowborough, East Sussex) located in a port in the animals breathing zone during the four-hour exposure period. The test atmosphere was generated to contain at least 19% oxygen.

Analytical verification of test atmosphere concentrations:

no

Remarks:

(Gravimetric Only)

Duration of exposure:

4 h

Concentrations:

Group 1:
Mean Achieved (mg/L): 5.09
Mean Mass Median Aerodynamic Diameter (um): 1.92
Inhalable Fraction (%<4um): 77.3
Geometric Standard Deviation: 2.69

Group 2:
Mean Achieved (mg/L): 1.05
Mean Mass Median Aerodynamic Diameter (um): 1.64
Inhalable Fraction (%<4um): 89.4
Geometric Standard Deviation:2.05

No. of animals per sex per dose:

3

Control animals:

no

Details on study design:

Clinical Signs
All animals were observed for clinical signs at hourly intervals during exposure, immediately on removal from the restraining tubes at the end of exposure, one hour after termination of exposure and subsequently once daily for up to fourteen days. Any deaths or evidence of overt toxicity were recorded at each observation.

Body Weight
Individual body weights were recorded on arrival, prior to treatment on the day of exposure and on Days 1, 3, 7 and 14 or at death.


Necropsy
At the end of the fourteen day observation period the surviving animals were killed by intravenous overdose of sodium pentobarbitone. All animals, including those that died during the course of the study were subjected to a full external and internal examination, and any macroscopic abnormalities were recorded. The respiratory tract was subjected to a detailed macroscopic examination for signs of irritancy or local toxicity. As deaths were noted, the following tissues were preserved; Lungs (inflated to approximately normal inspiratory volume, with buffered formalin) and the upper respiratory tract in buffered formalin.

Statistics:

Evaluation of Data
Data evaluations included the relationship, if any, between the animals’ exposure to the test item and the incidence and severity of all abnormalities including behavioral and clinical observations, necropsy findings, body weight changes, mortality and any other toxicological effects.

Using the mortality data obtained, an estimate of the acute inhalation median lethal concentration (LC50) of the test item was made.

Preliminary study:

Not applicable

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 1 - 5 mg/L air

Based on:

test mat.

Exp. duration:

4 h

Mortality:

1 male (Day 2) and 3 females (Day 1) animals were found dead post-exposure
1 male (Day 2) and 1 female (Day 1) animal were found dead post-exposure

Clinical signs:

other: Common abnormalities noted during the study included increased respiratory rate, hunched posture, pilo-erection and wet fur. There were occasional instances of tip-toe gait, isolated occurrences of labored respiration and ataxia were also noted. Survivi

Body weight:

Group 1 – All surviving animals exhibited body weight losses on Day 1 post-exposure. None of the female animals survived past Day 1 post-exposure, however, reasonable body weight development was noted in both of the surviving male animals during the remainder of the recovery period.

Group 2 – All animals exhibited body weight losses on Day 1 post-exposure. Reasonable body weight development was noted in all surviving male animals during the remainder of the recovery period. In contrast, two surviving female animals exhibited a slight body weight loss or showed no body weight gain from Days 1 to 3 post-exposure. Reasonable body weight gains were noted in these two animals during the remainder of the recovery period.

Gross pathology:

Pale patches on the lungs were noted in one of two surviving animals from Group 1 at necropsy. Dark patches on the lungs or pale lungs were noted in all four surviving animals from Group 2 at necropsy.

Abnormally dark lungs were detected in the animals that died during the course of the study at necropsy.

From consideration of results of Histopathological examinations of tissues retained from a study conducted on a similar test item (Harlan Study Number: 41300142) the deaths noted during this study may be attributable to hydrocarbon aspiration induced inflammation (i.e. a chemical pneumonitis).

Other findings:

Not Applicable

Exposure Chamber Atmosphere Concentrations – Dose Group 1

Duration of Exposure (minutes)	Net Weight of Sample (mg)	Volume of Air Sampled (L)	Chamber Flow Rate (L/min)	Atmosphere Concentration (mg/L)
5	10.16	2	60	5.08
15	10.51	2	60	5.26
30	10.15	2	60	5.08
45	10.03	2	60	5.02
60	10.22	2	60	5.11
75	10.14	2	60	5.07
90	10.11	2	60	5.06
105	10.05	2	60	5.03
120	10.18	2	60	5.09
135	9.94	2	60	4.97
150	10.38	2	60	5.19
165	10.41	2	60	5.21
180	10.00	2	60	5.00
195	10.17	2	60	5.09
210	10.12	2	60	5.06
225	10.24	2	60	5.12
238	10.14	2	60	5.07

 

Exposure Chamber Atmosphere Concentrations – Dose Group 2

Duration of Exposure (minutes)	Net Weight of Sample (mg)	Volume of Air Sampled (L)	Chamber Flow Rate (L/min)	Atmosphere Concentration (mg/L)
5	4.85	4	60	1.21
15	4.87	4	60	1.22
30	4.21	4	60	1.05
45	4.08	4	60	1.02
60	4.01	4	60	1.00
75	4.13	4	60	1.03
90	4.03	4	60	1.01
105	4.08	4	60	1.02
120	4.04	4	60	1.01
135	4.03	4	60	1.01
150	4.17	4	60	1.04
165	4.09	4	60	1.02
180	4.15	4	60	1.04
195	4.11	4	60	1.03
210	4.15	4	60	1.04
225	4.10	4	60	1.03
238	4.29	4	60	1.07

 

Particle Size Distribution – Dose Group 1

Cascade Impactor Data

 

Impactor Stage Number	Cut Point (µm)	Amount Collected (mg) per Sample Number			Mean Amount Collected (mg)
		1	2	3
3	8.9	0.12	0.14	0.06	0.11
4	6.2	0.17	0.11	0.09	0.12
5	3.6	0.48	0.36	0.27	0.37
6	1.6	1.09	0.71	0.66	0.82
7	0.93	0.15	0.13	0.11	0.13
8	0.37	0.57	0.38	0.40	0.45
Back-up Filter	<0.37	0.16	0.05	0.14	0.12
Total Mean Amount of Test Item Collected					2.12

 

Calculation

 

Cut Point (µm)	Log10 Cut Point	Mean Cumulative Amount Less Than Cut Point
		(mg)	(%)	Probit
8.9	0.949	2.01	94.8	6.63
6.2	0.792	1.89	89.2	6.24
3.6	0.556	1.52	71.7	5.57
1.6	0.204	0.70	33.0	4.56
0.93	-0.032	0.57	26.9	4.38
0.37	-0.432	0.12	5.66	3.42

 

Results

 

Mean Mass Median Aerodynamic Diameter (MMAD) =1.92µm

Geometric Standard Deviation (GSD) =2.69

Predicted amount less than 4 µm =77.3%

Particle Size Distribution – Dose Group 2

Cascade Impactor Data

 

Impactor Stage Number	Cut Point (µm)	Amount Collected (mg) per Sample Number			Mean Amount Collected (mg)
		1	2	3
3	8.9	0.00	0.00	0.02	0.01
4	6.2	0.00	0.02	0.02	0.01
5	3.6	0.05	0.09	0.11	0.08
6	1.6	0.26	0.59	0.58	0.48
7	0.93	0.00	0.09	0.00	0.03
8	0.37	0.11	0.28	0.26	0.22
Back-up Filter	<0.37	0.00	0.04	0.03	0.02
Total Mean Amount of Test Item Collected					0.85

 

Calculation

 

Cut Point (µm)	Log10 Cut Point	Mean Cumulative Amount Less Than Cut Point
		(mg)	(%)	Probit
8.9	0.949	0.84	98.8	7.27
6.2	0.792	0.83	97.6	6.99
3.6	0.556	0.75	88.2	6.19
1.6	0.204	0.27	31.8	4.53
0.93	-0.032	0.24	28.2	4.42
0.37	-0.432	0.02	2.35	3.01

 

Results

 

Mean Mass Median Aerodynamic Diameter (MMAD) = 1.64 µm

Geometric Standard Deviation (GSD) = 2.05

Predicted amount less than 4 µm = 89.4 %

 

KEY TO CLINICAL OBSERVATIONS

A	=	ataxia
H	=	hunched posture
P	=	pilo-erection
Ri	=	increased respiratory rate
Rl	=	labored respiration
Wf	=	wet fur
Wt	=	tip-toe gait
0	=	no abnormalities detected
X	=	animal dead

 

Individual Clinical Observations (Day of Exposure) – Dose Group 1

Mean Achieved Atmosphere Concentration (mg/L)	Animal Number and Sex	Hours During Exposure			On Removal From Chamber	One Hour Post-Exposure
		1	2	3
5.09	1 Male	Wf Ri	Wf Ri	Wf Ri	Wf H P Ri Wt	H P Ri Wt
	2 Male	Wf	Wf Ri	Wf Ri	Wf H P Ri	H P Ri
	3 Male	Wf Ri	Wf Ri	Wf Ri	Wf H P Ri	Wf H P Ri
	4 Female	Wf	Wf Ri	Wf Ri	Wf H P Ri Wt	Wf H P Ri Wt
	5 Female	Wf	Wf Ri	Wf Ri	Wf H P Ri Wt	Wf H P Ri Wt
	6 Female	Wf	Wf Ri	Wf Ri	Wf H P Ri	H P Ri

 

Individual Clinical Observations (Recovery Period) – Dose Group 1

Mean Achieved Atmosphere Concentration (mg/L)	Animal Number and Sex	Days Post Exposure
		1	2	3	4	5	6	7	8 - 14
5.09	1 Male	H P Ri	X
	2 Male	H P Ri	H P Ri	H Ri	H Ri	H Ri	Ri	Ri	0
	3 Male	H P Ri	H P Ri	H Ri	H Ri	Ri	Ri	Ri	0
	4 Female	X
	5 Female	X
	6 Female	H P Ri Rl A Xlater in the day

 

Individual Clinical Observations (Day of Exposure) – Dose Group 2

Mean Achieved Atmosphere Concentration (mg/L)	Animal Number and Sex	Hours During Exposure			On Removal From Chamber	One Hour Post-Exposure
		1	2	3
1.05	7 Male	Wf Ri	Wf Ri	Wf Ri	Wf H P Ri	Wf H P Ri
	8 Male	Wf	Wf Ri	Wf Ri	Wf H P Ri	Wf H P Ri
	9 Male	Wf Ri	Wf Ri	Wf Ri	Wf H P Ri	Wf H P Ri
	10 Female	Wf Ri	Wf Ri	Wf Ri	Wf H P Ri	Wf H P Ri
	11 Female	Wf	Wf Ri	Wf Ri	Wf H P Ri	Wf H P Ri
	12 Female	Wf Ri	Wf Ri	Wf Ri	Wf H P Ri	Wf H P Ri

 

Individual Clinical Observations (Recovery Period) – Dose Group 2

Mean Achieved Atmosphere Concentration (mg/L)	Animal Number and Sex	Days Post Exposure
		1	2	3	4	5	6	7
1.05	7 Male	H P Ri	H P Ri	P Ri	P Ri	Ri	Ri	0
	8 Male	H P Ri	X
	9 Male	H P Ri	H P Ri	P Ri	P Ri	Ri	Ri	0
	10 Female	H P Ri	H P Ri	H P Ri	H P Ri	Ri	Ri	Ri
	11 Female	H P Ri	H P Ri	H P Ri Rl	H P Ri	Ri	Ri	Ri
	12 Female	H P Ri A XLater in the day

 

(Continued)   Individual Clinical Observations (Recovery Period) – Dose Group 2

Mean Achieved Atmosphere Concentration (mg/L)	Animal Number and Sex	Days Post Exposure
		8	9	10	11	12	13	14
1.05	7 Male	0	0	0	0	0	0	0
	8 Male
	9 Male	0	0	0	0	0	0	0
	10 Female	Ri	Ri	Ri	Ri	Ri	0	0
	11 Female	Ri	Ri	Ri	Ri	Ri	0	0
	12 Female

Interpretation of results:

Category 4 based on GHS criteria

Remarks:

Criteria used for interpretation of results: other: Globally Harmonized Classification System

Conclusions:

Four out of six animals died at a mean achieved atmosphere concentration of 5.09 mg/L, whereas, two deaths occurred in a group of six rats exposed to a mean achieved atmosphere concentration of 1.05 mg/L. It was therefore considered that the acute inhalation median lethal concentration (4 hr LC50) of GTL Base oil 3, in the RccHanTM : WIST strain rat, was in the range >1 mg/L to 5 mg/L (Globally Harmonized Classification System – Category 4).

Executive summary:

Introduction

A study was performed to assess the acute inhalation toxicity of the test item. The method used was compatible with that described in the OECD Guidelines for Testing of Chemicals (2009) No. 436 “Acute Inhalation Toxicity – Acute Toxic Class Method”.

 

Methods.......

Two groups of six RccHan™ : WIST strain rats (three males and three females) were exposed to an aerosol atmosphere. The animals were exposed for four hours using a nose only exposure system, followed by a fourteen day observation period.

 

Results……..

The mean achieved atmosphere concentration was as follows:

 

Group Number	Atmosphere Concentration
	Mean Achieved (mg/L)	Standard Deviation	Nominal (mg/L)
1	5.09	0.07	12.7
2	1.05	0.06	2.14

 

The characteristics of the achieved atmosphere were as follows:

 

Group Number	Mean Achieved Atmosphere Concentration (mg/L)	Mean Mass Median Aerodynamic Diameter (µm)	Inhalable Fraction (% <4 µm)	Geometric Standard Deviation
1	5.09	1.92	77.3	2.69
2	1.05	1.64	89.4	2.05

 

The mortality data were summarized as follows:

 

Group Number	Mean Achieved Atmosphere Concentration (mg/L)	Deaths
		Male	Female	Total
1	5.09	1/3	3/3	4/6
2	1.05	1/3	1/3	2/6

 

 

Clinical Observations

Common abnormalities noted during the study included increased respiratory rate, hunched posture, pilo-erection and wet fur. There were occasional instances of tip-toe gait, isolated occurrences of labored respiration and ataxia were also noted. Surviving Group 1 animals recovered to appear normal on Day 8 post-exposure. Surviving Group 2 animals recovered to appear normal from Days 7 to 13 post-exposure. 

Body Weight

Group 1 – All surviving animals exhibited body weight losses on Day 1 post-exposure. None of the female animals survived past Day 1 post-exposure, however, reasonable body weight development was noted in both of the surviving male animals during the remainder of the recovery period. 

 

Group 2 – All animals exhibited body weight losses on Day 1 post-exposure. Reasonable body weight development was noted in all surviving male animals during the remainder of the recovery period. In contrast, two surviving female animals exhibited a slight body weight loss or showed no body weight gain from Days 1 to 3 post-exposure. Reasonable body weight gains were noted in these two animals during the remainder of the recovery period.

 

 

Necropsy

Pale patches on the lungs were noted in one of two surviving animals from Group 1 at necropsy. Dark patches on the lungs or pale lungs were noted in all four surviving animals from Group 2 at necropsy.

 

Abnormally dark lungs were detected in the animals that died during the course of the study at necropsy.

 

From consideration of results of Histopathological examinations of tissues retained from a study conducted on a similar test item (Harlan Study Number: 41300142) the deaths noted during this study may be attributable to hydrocarbon aspiration induced inflammation (i.e. a chemical pneumonitis).

 

 

Conclusion

Four out of six animals died at a mean achieved atmosphere concentration of 5.09 mg/L, whereas, two deaths occurred in a group of six rats exposed to a mean achieved atmosphere concentration of 1.05 mg/L. It was therefore considered that the acute inhalation median lethal concentration (4 hr LC₅₀) ofGTL Base oil3, in the RccHan^TM: WIST strain rat, was in the range >1 mg/L to 5 mg/L (Globally Harmonized Classification System – Category 4).

Reference 3

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

Experimental Starting Date: 29 January 2013 Experimental Completion Date: 01 July 2013

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Study conducted on supporting substance (with range, C8-26) in compliance with agreed protocols, with no or minor deviations from standard test guidelines and/or minor methodological deficiencies, which do not affect the quality of the relevant results. The study report was conclusive, done to a valid guideline and the study was conducted under GLP conditions. Read-across is considered to be reliability 2.

Justification for type of information:

A discussion and report on the read across strategy is given as an attachment in IUCLID Section 13.

Reason / purpose for cross-reference:

read-across: supporting information

Qualifier:

according to guideline

Guideline:

OECD Guideline 436 (Acute Inhalation Toxicity: Acute Toxic Class Method)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test type:

acute toxic class method

Limit test:

yes

Species:

rat

Strain:

other: RccHan™ : WIST strain rats

Sex:

male/female

Details on test animals or test system and environmental conditions:

Male and female RccHan™ : WIST strain rats were supplied by reputable supplier. On receipt the animals were randomly allocated to cages. After an acclimatization period of at least five days the animals were given a number unique within the study by ear punching and a number written on a color coded cage card. At the start of the study the animals were approximately eight to twelve weeks old and within the weight range of 200g to 354g*.

The females were nulliparous and non-pregnant.

The animals were housed in groups of up to three by sex in solid-floor polypropylene cages with stainless steel lids, furnished with softwood flakes and provided with environmental enrichment items: wooden chew blocks and cardboard “fun tunnels”.

With the exception of the exposure period, free access to mains drinking water and food was allowed throughout the study. The diet, drinking water, bedding and chew blocks are routinely analyzed and are considered not to contain any contaminants that could reasonably be expected to affect the purpose or integrity of the study.

The environmental controls were set to achieve values of 19 – 25 °C and 30 – 70 % relative humidity. The rate of air exchange was at least fifteen changes per hour and the lighting was controlled to give twelve hours continuous light and twelve hours darkness. The animals were retained in this accommodation at all times except during the exposure period.

* = One male animal from Group 2 was slightly outside the weight range specified in the Study Plan (200g to 350g).
This deviation was considered not to affect the purpose or validity of this study.

Route of administration:

inhalation: aerosol

Type of inhalation exposure:

nose only

Vehicle:

clean air

Details on inhalation exposure:

Atmosphere Generation
The test item was aerosolized using a glass concentric jet nebulizer located at the top of the exposure chamber. The nebulizer was connected to a plastic syringe attached to an infusion pump, which provided a continuous supply of test item under pressure, and to a metered compressed air supply.

Compressed air was supplied by means of an oil free compressor and passed through a water trap and respiratory quality filters before it was introduced to the nebulizer.

The cylindrical exposure chamber had a volume of approximately 30 liters (dimensions: 28 cm diameter x 50 cm high). The concentration within the exposure chamber was controlled by adjusting the rate of the infusion pump. The extract from the exposure chamber passed through a ‘scrubber’ trap and was connected with a high efficiency filter to a metered exhaust system. The chamber was maintained under negative pressure. A diagram of the dynamic (continuous flow) system employed is shown in the attached Figure 1.

Homogeneity of the test atmosphere within the chamber was not specifically determined during this study. Chambers of the same design have been fully validated and shown to produce evenly distributed atmospheres in the animals’ breathing zone with a wide variety of test items (Green J D et al, 1984). Prior to the start of the study, test item atmospheres were generated within the exposure chamber.

During this characterization period test item input rates and air flow settings were varied to achieve the required atmospheric conditions.

Exposure Procedure
On the day of exposure (Group 1) and prior to the day of exposure (Group 2) each rat was acclimatized (for approximately 2 hours) to a tapered polycarbonate restraining tube. During the exposure period, each rat was individually held in a tapered, polycarbonate restraining tube fitted onto a single tier of the exposure chamber and sealed by means of a rubber ‘O’ ring. Only the nose of each animal was exposed to the test atmosphere.

Following an appropriate equilibration period two groups, each of six rats (three males and three females), were subjected to a single exposure to the test item for a period of four hours. Based on the expected toxicity of the test item, a target concentration of 5.0 mg/L was used for the first exposure. The second concentration was selected after consideration of the results of the first exposure.

Exposure Chamber Temperature and Relative Humidity
The temperature and relative humidity inside the exposure chamber were measured by an electronic thermometer/humidity meter located in a vacant port in the animals’ breathing zone of the chamber and recorded every thirty minutes throughout the four-hour exposure period. Individual values are given in the attached Table 14 and 15.

Exposure Chamber Oxygen Concentration
Oxygen levels within the exposure chamber were measured by an electronic oxygen analyzer located in a port in the animals breathing zone during the four-hour exposure period. The test atmosphere was generated to contain at least 19% oxygen. Individual values are given in the attached Table 16.

Analytical verification of test atmosphere concentrations:

yes

Duration of exposure:

4 h

Concentrations:

Group 1 mean achieved atmosphere concentration of 5.61 mg/L group 2 mean achieved atmosphere concentration 5.11 mg/L

No. of animals per sex per dose:

Two groups of six RccHan™ : WIST strain rats (three males and three females)

Control animals:

no

Details on study design:

Clinical Signs
All animals were observed for clinical signs at hourly intervals during exposure, immediately on removal from the restraining tubes at the end of exposure, one hour after termination of exposure and subsequently once daily for up to fourteen days. Any evidence of overt toxicity was recorded at each observation.

Body Weight
Individual body weights were recorded on arrival, prior to treatment on the day of exposure and on Days 1, 3, 7 and 14.

Necropsy
At the end of the fourteen day observation period the animals were killed by intravenous overdose of sodium pentobarbitone. All animals were subjected to a full external and internal examination, and any macroscopic abnormalities were recorded. The respiratory tract was subjected to a detailed macroscopic examination for signs of irritancy or local toxicity.

Statistics:

Evaluation of Data
Data evaluations included the relationship, if any, between the animals’ exposure to the test item and the incidence and severity of all abnormalities including behavioral and clinical observations, necropsy findings, body weight changes, mortality and any other toxicological effects. Using the mortality data obtained, an estimate of the acute inhalation median lethal concentration (LC50) of the test item was made.

Preliminary study:

Dose Group 1 – 5.61 mg/L
During exposure all animals exhibited increased respiratory rate and there were occasional instances of labored respiration. On removal from the chamber all animals exhibited increased respiratory rate and labored respiration. One hour post-exposure, little or no change in the condition of the animals was noted.

One day after exposure, one male and one female animal were found dead. All surviving animals exhibited increased respiratory rate, hunched posture and pilo-erection. Isolated occurrences of labored respiration, splayed gait, tip-toe gait and ptosis were also noted in one female animal. Observations gradually receded over the recovery period such that surviving animals recovered to appear normal from Days 8 to 9 post-exposure.

Key result

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 5 mg/L air

Based on:

test mat.

Exp. duration:

4 h

Remarks on result:

other: 95 % CL not reported.

Mortality:

For full details please see attached tables 6 to 9

Group 1: One male and one female animal were found dead from a group of six rats exposed to a mean achieved atmosphere concentration of 5.61 mg/L one day after exposure

Group 2: One female animal was found dead from a group of six rats exposed to a mean achieved atmosphere concentration of 5.11 mg/L one day after exposure

Clinical signs:

other: Individual clinical observations are given in the attached Tables 6 to 9. Dose Group 1 – 5.61 mg/L During exposure all animals exhibited increased respiratory rate and there were occasional instances of labored respiration. On removal from the chamber a

Body weight:

Individual body weights, together with body weight changes, are given in the attached Tables 10 and 11.

Group 1 – All surviving animals exhibited bodyweight losses on Day 1 post-exposure. With the exception of one female animal which showed no body weight gain from Days 1 to 3 post-exposure, reasonable bodyweight development was noted in all surviving animals during the remainder of the recovery period.
Group 2 – All surviving animals exhibited bodyweight losses on Day 1 post-exposure.
Reasonable bodyweight development was noted in all animals during the remainder of the recovery period.

Gross pathology:

Individual necropsy findings are given in the attached Tables 12 and 13.

Pale or dark patches on the lungs were noted at necropsy amongst four surviving animals from Group 1 and in two out of five surviving animals from Group 2 at the end of the fourteen day recovery period.

The following macroscopic abnormalities were detected in the animals that died during the course of the study at necropsy:
Lungs – abnormally dark or dark patches;
Stomach – gaseous distension;
Large Intestine – gaseous distension.

Due to the observations noted it is considered that the death noted during the study may have been mainly attributable to local toxicity.

Dark patches in the lungs and abnormally dark lungs in a proportion of animals in both treatment groups were associated with congestion and hemorrhage at histopathological examination, and were considered to be treatment-related.

Other findings:

A complete histopathology phase report is presented in the attached Appendix 3.

Histopathology
The following treatment-related findings were present in the lungs of animals surviving to
terminal sacrifice:
- minimal to moderate congestion
- minimal to slight hemorrhage
- minimal to moderate edema
- minimal to slight alveolar macrophages
- minimal acute alveolar inflammation
- minimal acute perivascular inflammation
The following treatment-related findings were present in the lungs of premature decedent animals:
- moderate congestion
- slight hemorrhage
- minimal to slight alveolar macrophages
- slight acute alveolar inflammation
There were no findings in the trachea.

Signs of hunched posture and pilo-erection are commonly seen in animals for short periods on removal from the chamber following 4-hour inhalation studies. Wet fur and red/brown staining around the eyes are commonly recorded both during and for a short period after exposure. These observations are considered to be associated with the restraint procedure and, in isolation, are not indicative of toxicity.

Exposure Chamber Concentration The test atmosphere (Group 1) was sampled seventeen times during the exposure period and the actual concentration of the test item calculated.

The actual concentration (Group 2) of the test item was determined by gas chromatography (GC). The test atmospheres were sampled after theoretical chamber equilibration and then at approximately half-hourly intervals during the exposure period.

The mean values obtained for each group were:

Group number	Atmosphere Concentration
	Mean Achieved (mg/L)	Standard Deviation	Nominal (mg/L)
1	5.61	0.23	15.3
2	5.11	0.09	11.7

The exposure chamber concentrations are given in the attached Tables 1 and 2 and are presented graphically in the attached Figures 2 and 3. The chamber flow rate was maintained at 60 L/min providing 120 air changes per hour. The theoretical chamber equilibration time (T99) was 3 minutes* (Silver, 1946).

Particle Size Distribution

The particle size analysis of the atmosphere drawn from the animals’ breathing zone, was as follows:

Group number	Mean Achieved Atmosphere Concentration (mg/L)	Mean Mass Median Aerodynamic Diameter (μm)	Inhalable Fraction (% <4μm)	Geometric Standard Deviation
1	5.61	2.78	65.7	2.48
2	5.11	2.16	77.5	2.27

The particle size distribution data is presented in the attached Tables 3 and 4 and graphs showing the distribution are presented in the attached Figures 4 to 7.

* = The test atmosphere was generated for 7 minutes and 14 minutes prior to animal insertion (for Groups 1 and 2

respectively) to ensure test item concentration was being achieved.

Interpretation of results:

other: Not classified

Remarks:

Criteria used for interpretation of results: EU

Conclusions:

Two deaths occurred in a group of six rats exposed to a mean achieved atmosphere concentration of 5.61 mg/L, whereas, one death occurred at a mean achieved atmosphere concentration of 5.11 mg/L. It was therefore considered that the acute inhalation median lethal concentration (4 hr LC50) of 'Distillates (Fischer-Tropsch), C8-26-branched and linear', in the RccHanTM : WIST strain rat, was >5 mg/L.

The microscopic findings observed in the lungs (alveolar and perivascular inflammation, edema, congestion and hemorrhage) were all consistent with hydrocarbon aspiration induced inflammation (i.e. a chemical pneumonitis).

Executive summary:

Introduction

A study was performed to assess the acute inhalation toxicity of the test item. The method used was compatible with that described in the OECD Guidelines for Testing of Chemicals (2009) No. 436 “Acute Inhalation Toxicity – Acute Toxic Class Method”.

 

Methods.......

Two groups of six RccHan™ : WIST strain rats (three males and three females) were exposed to an aerosol atmosphere. The animals were exposed for four hours using a nose only exposure system, followed by a fourteen day observation period.

 

Results……..

The mean achieved atmosphere concentration was as follows:

Group number	Atmosphere Concentration
	Mean Achieved (mg/L)	Standard Deviation	Nominal (mg/L)
1	5.61	0.23	15.3
2	5.11	0.09	11.7

 

Group number	Mean Achieved Atmosphere Concentration (mg/L)	Mean Mass Median Aerodynamic Diameter (μm)	Inhalable Fraction (% <4 μm)	Geometric Standard Deviation
1	5.61	2.78	65.7	2.48
2	5.11	2.16	77.5	2.27

 

Group Number	Mean Achieved Atmosphere Concentration (mg/L)	Deaths
		Male	Female	Total
1	5.61	1/3	1/3	2/6
2	5.11	0/3	1/3	1/6

 

Clinical Observations

Common abnormalities noted during the study included increased respiratory rate, labored respiration, hunched posture, pilo-erection and wet fur. There were occasional instances of tiptoe gait and red/brown staining around the eyes, isolated occurrences of splayed gait, ptosis and red/brown staining around the snout were also noted. Surviving Group 1 animals recovered to appear normal from Days 8 to 9 post exposure. Surviving Group 2 animals recovered to appear normal from Days 7 to 8 post-exposure.

 

Body Weight

Group 1 – All surviving animals exhibited bodyweight losses on Day 1 post-exposure. With the exception of one female animal which showed no body weight gain from Days 1 to 3 postexposure, reasonable bodyweight development was noted in all surviving animals during the remainder of the recovery period.

 

Group 2 – All surviving animals exhibited bodyweight losses on Day 1 post-exposure. Reasonable bodyweight development was noted in all animals during the remainder of the recovery period.

 

Necropsy

Pale or dark patches on the lungs were noted at necropsy amongst four surviving animals from Group 1 and in two out of five surviving animals from Group 2 at the end of the fourteen day recovery period.

 

The following macroscopic abnormalities were detected in the animals that died during the course of the study at necropsy:

Lungs – abnormally dark or dark patches;

Stomach – gaseous distension;

Large Intestine – gaseous distension.

Due to the observations noted it is considered that the death noted during the study may have been mainly attributable to local toxicity.

Dark patches in the lungs and abnormally dark lungs in a proportion of animals in both treatment groups were associated with congestion and hemorrhage at histopathological examination, and were considered to be treatment-related.

 

Histopathology

The following treatment-related findings were present in the lungs of animals surviving to terminal sacrifice:

- minimal to moderate congestion

- minimal to slight hemorrhage

- minimal to moderate edema

- minimal to slight alveolar macrophages

- minimal acute alveolar inflammation

- minimal acute perivascular inflammation

The following treatment-related findings were present in the lungs of premature decedent

animals:

- moderate congestion

- slight hemorrhage

- minimal to slight alveolar macrophages

- slight acute alveolar inflammation

There were no findings in the trachea.

 

Conclusion

Two deaths occurred in a group of six rats exposed to a mean achieved atmosphere concentration of 5.61 mg/L, whereas, one death occurred at a mean achieved atmosphere concentration of 5.11 mg/L. It was therefore considered that the acute inhalation median lethal concentration (4 hr LC50) of 'Distillates (Fischer-Tropsch), C8-26-branched and linear', in the RccHanTM: WIST strain rat, was >5 mg/L.

The microscopic findings observed in the lungs (alveolar and perivascular inflammation, edema, congestion and hemorrhage) were all consistent with hydrocarbon aspiration induced inflammation (i.e. a chemical pneumonitis).

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LC50

Value:

5 000 mg/m³

Quality of whole database:

The available studies are GLP compliant and have Klimisch score 2.

Acute toxicity: via dermal route

Link to relevant study records

Reference

Reference 1

Endpoint:

acute toxicity: dermal

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

other:

Reference 2

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: The study on supporting substance (with limited range, C8-26) was conducted according to OECD guideline and in compliance with GLP. Read-across considered to be reliability 2.

Justification for type of information:

A discussion and report on the read across strategy is given as an attachment in IUCLID Section 13.

Reason / purpose for cross-reference:

read-across: supporting information

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Qualifier:

according to guideline

Guideline:

EU Method B.3 (Acute Toxicity (Dermal))

GLP compliance:

yes

Test type:

standard acute method

Limit test:

yes

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Harlan laboratories, UK
- Age at study initiation: 8-12 weeks
- Weight at study initiation: minimum 200 g
- Fasting period before study:
- Housing: solid floor polypropylene cages, furnished with woodflakes
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: minimum 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19-25
- Humidity (%): 30-70
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12/12

Type of coverage:

semiocclusive

Vehicle:

unchanged (no vehicle)

Details on dermal exposure:

TEST SITE
- Area of exposure: not defined
- % coverage: ca. 10%
- Type of wrap if used: surgical gauze, semi-occluded with a piece of self-adhesive bandage

REMOVAL OF TEST SUBSTANCE
- Washing (if done): the skin was wiped with cotton wool, moistened with arachis oil BP
- Time after start of exposure: 24 hours

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 2.62 mL/kg
- Concentration (if solution): undiluted
- Constant volume or concentration used: yes

Duration of exposure:

24 hours

Doses:

2000 mg/kg bw

No. of animals per sex per dose:

5/sex

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: the animals were observed for deaths and overt signs of toxicity at 0.5, 1, 2, and 4 hours after dosing. Individual body weights were recorded prior to application of the test item on day 0, 7 and 14.
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight, organ weights, histopathology, other: The test sites were examined for evidence of primary irritation and scored. The appearance of any macroscopic abnormalities were recorded at necropsy, no tissues were retained.

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

There were no deaths.

Clinical signs:

There were no signs of systemic toxicity.

Body weight:

All animals showed expected gains in body weight.

Gross pathology:

No abnormalities were noted at necropsy.

Other findings:

Very slight erythema and crust formation and/or small superficial scattered scabs were noted at the test sites of four females. There were no signs of dermal irritation noted at the test sites of the remaining animals.

Interpretation of results:

other: Not classified

Remarks:

Criteria used for interpretation of results: EU

Conclusions:

An LD50 value of >2000 mg/kg bw is reported in a reliable study conducted according to an OECD test guideline and in compliance with GLP.

Executive summary:

The acute dermal toxicity study is a reliable test performed with Distillates (Fischer-Tropsch), C8-26 – branched and linear, in accordance with OECD 402 and in compliance with GLP. 2000 mg/kg bw of test substance was applied to five male and five female Wistar rats for a twenty-four hour exposure period under semiocclusive conditions. The animals were observed for deaths or overt signs of toxicity, and the test sites were observed for primary irritation for fourteen days before sacrifice and necroscopy. No deaths occurred and no signs of overt toxicity were observed. There were no abnormalities noted at necroscopy. Very slight erythema and crust formation and/or small superficial scattered scabs were noted at the test sites of four females. There were no signs of dermal irritation noted at the test sites of the remaining animals.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

2 000 mg/kg bw

Quality of whole database:

The available study is GLP compliant and have Klimisch score 2.

Additional information

No acute oral, dermal, or inhalation toxicity data is available for docosane. However, key oral toxicity and supporting dermal and inhalation toxicity data is available from structurally related substances, C18-C50 branched, cyclic and linear hydrocarbons – Distillates (CAS# 848301-69-9) and C8-C26 branched and linear hydrocarbons – Distillates (CAS# 848301-67-7) and is presented below.

Acute oral toxicity:

The study was performed to assess the acute oral toxicity of C18-C50 branched, cyclic and linear hydrocarbons – Distillates (CAS# 848301-69-9) in the Sprague-Dawley CD strain rat. The method was designed to meet the requirements of OECD Guideline No 420 "Acute Oral Toxicity - Fixed Dose Method" and Method B1 bis Acute Toxicity (Oral) of Commission Directive 2004/73/EC. A dose level of 5000 mg/kg bodyweight resulted in no deaths, no signs of systemic toxicity, expected gains in bodyweight and no abnormalities at necropsy, in a total of 5 animals. The acute oral median lethal dose (LD₅₀) of the test material in the female Sprague-Dawley CD strain rat was estimated to be greater than 5000 mg/kg bodyweight.

Acute inhalation and dermal toxicity:

No studies conducted on the test substance. However, based on lack of skin irritation and systemic effects in a skin irritation study the substance is not considered to acute harmful in contact with skin. The substance is unlikely to form aerosols or particles of inhalable size and therefore it is considered justifiable not to conduct inhalation study.

Moreover, supporting data on a related substance (with range C8 -26) indicate the low toxicity of the test substance:

- Acute inhalation toxicity study (Shell, 2013a), conducted according to OECD 436 and GLP, reported an acute inhalation median lethal concentration (4 hr LC₅₀) of Distillates (Fischer-Tropsch), C8-26-branched and linear, in the RccHanTM: WIST strain rat >5 mg/L.

- Acute dermal toxicity study (Shell, 2015a), conducted according to OECD 402 (Acute Dermal Toxicity) and GLP, reported an LD₅₀ in male and female rats >2000 mg/kg bw.

Justification for selection of acute toxicity – oral endpoint
No study available for substance defined in Section 1. For the endpoint conclusion a study of a related substance C18-C50 branched, cyclic and linear hydrocarbons – Distillates (CAS# 848301-69-9) was selected.

Justification for selection of acute toxicity – inhalation endpoint
No study available for substance defined in section 1. For the endpoint conclusion a study of a related substance with a limited range (C8-C26) was selected.

Justification for selection of acute toxicity – dermal endpoint
No study available for substance defined in section 1. For the endpoint conclusion a study of a related substance with a limited range (C8-C26) was selected.

Justification for classification or non-classification

On the basis of the available read across oral, inhalation and dermal data, docosane does not require classification for lethal effects following a single exposure according to Regulation 1272/2008/EC.