Renewable hydrocarbons (naphtha type fraction)

Endpoint summary

Description of key information

Acute oral toxicity: The LD50 value for the substance is 2000 mg/kg bw.
Acute dermal toxicity: The LD50 values for read-across substances are greater than 2 920 mg/kg bw.
Acute inhalation toxicity: The LC50 value for read-across substance is 23 400 mg/m3

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:

26 April 2012 - 17 May 2012

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: The study was conducted according to the OECD 420 guideline and in compliance with GLP.

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes

Test type:

fixed dose procedure

Species:

rat

Strain:

Wistar

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: harlan Laboratories UK Ltd., Oxon, UK
- Age at study initiation: eight to twelve weeks
- Weight at study initiation: 156-165 g
- Fasting period before study: overnight fast immediately before dosing and for approximately three to four hours after dosing
- Housing: in groups of up to four in suspended solid-floor polypropylene cages furnished with woodflakes
- Diet (e.g. ad libitum): 2014C Teklad Global Rodent diet ad libitum
- Water (e.g. ad libitum): drinking water ad libitum
- Acclimation period: at least five days

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

Route of administration:

oral: gavage

Vehicle:

unchanged (no vehicle)

Details on oral exposure:

Using available information on the toxicity of the test item, one animal was gavaged at a dose level of 2000 mg/kg. In the absence of toxicity, an additional group of animals (four) were gavaged at 2000 mg/kg bw. All animals were dosed once using metal cannula attached to a graduated syringe. The volume administered to each animal was calculated according to its fasted bodyweight at the time of dosing.

Doses:

2000 mg/kg bw

No. of animals per sex per dose:

5

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Clinical observations were made 0.5, 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 0 (the day of dosing) and on Days 7 and 14.
- Necropsy of survivors performed: yes/no
- Other examinations performed: clinical signs, body weight,organ weights, histopathology, other:

Preliminary study:

2000 mg/kg bw was chosen as the starting dose, no mortality was observed.

Sex:

female

Dose descriptor:

LD50

Effect level:

2 000 mg/kg bw

Based on:

test mat.

Mortality:

There were no deaths

Clinical signs:

other: No signs of systemic toxicity were noted

Gross pathology:

No abnormalities were noted at necropsy

Other findings:

- Organ weights: not measured
- Histopathology: not examined
- Potential target organs: not observed
- Other observations: none

Interpretation of results:

study cannot be used for classification

Conclusions:

The acute oral medial lethal dose (LD50) of the test item in the female rat was estimated to be greater than 2000 mg/kg bodyweight.

Executive summary:

The objective of this study was to assess the toxicity of the test item when administered in a single oral dose (2000 mg/kg bw) to female rats. No mortalities were observed at the tested dose level.

The study is considered reliable without restrictions since the study is carried out based on the OECD No. 420 guideline and in compliance with principles of Good Laboratory Paractice (GLP).

Based on these results, the test item does not have to be classified and has no obligatory labeling requirement for acute oral toxicity according to CLP Regulation 1272/2008 and Directive 67/548/EEC.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

2 000 mg/kg bw

Acute toxicity: via inhalation route

Link to relevant study records

Reference

Endpoint:

acute toxicity: inhalation

Type of information:

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

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Remarks:

The study does not comply fully with the specific testing guideline. However, the study is well documented and the method used is scientically acceptable. The information in the publication is used to support the waiver.

Justification for type of information:

Read-across justification: Based on the chemical composition, the renewable hydrocarbons obtained from the catalytic hydrotreatment of wood oil with or without the addition of vegetable oils and/or animal fats have similar hydrocarbon fractions and they contain the same critical constituents than fossil fuels (low boiling naphthas). Naphtha is a generic term used to describe volatile, flammable hydrocarbon fractions. The target substance and the sources substances (naphthas) meet same physical-chemical and technical performance specifications in Europe (EN 228). These fuel specifications include limits for the certain properties (vapour pressure and boiling point) which are also important considering the similarities in the toxicological profiles and the toxicokinetic behaviour as well as the relevant exposure routes of the substance. Based on the content of saturated, olefinic and aromatic hydrocarbons, the typical carbon number range and the physicochemical properties, the renewable hydrocarbons with gasoline type fractions can be considered as having structural similarities and similar behaviour in contact with water and in the physiological processes than the analogue source substances (fossil gasolines). Their irritation and skin sensitisation as well as acute and long-term adverse effects to human health is similar. Therefore, and in order to avoid the unnecessary animal testing, the read-across data from the analogue fossil gasolines is used to evaluate the irritation, sensitisation and short term and/or long-term toxicological effects of the target substance.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Principles of method if other than guideline:

Male Sprague Dawley rats were exposed to inhaltion of n-C9 to n-C13 alkanes close to air saturation at 20 deg. C (4438, 1369, 442, 142 and 41 ppm, respectively) for 8 hours and observed for the following 14 days. In addition, exposure to higher and lower concentrations of n-C9 alkane was performed.

GLP compliance:

not specified

Test type:

other: Modification of the standard method

Species:

rat

Strain:

Sprague-Dawley

Sex:

male

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Mollegaard A/S, Ll. Skensved, Denmark
- Weight at study initiation: 180-220 g
- Acclimation period: 4-6 d
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21-23
- Humidity (%): 40-70
- Photoperiod (hrs dark / hrs light): 12/12

Route of administration:

inhalation: vapour

Type of inhalation exposure:

whole body

Vehicle:

clean air

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: conical 0.7 m3 steel chambers with glass front door and walls; flow rate 30-40 l/min.
- Vapour generation: test substance warmed (approx. 22 degrees C) under negative pressure and mixed with clean air to achieve required concentration
- Method of particle size determination:The presence of alkane aerosol in the inhalation chamber during exposure was investigated by Royco mod. 255 particlem onitorwith an aerosol particle counter sensor mod 241
- Temperature, humidity, pressure in air chamber: slightly higher than in the vapour generation, negative pressure 2-5 mm H20.

TEST ATMOSPHERE
- Brief description of analytical method used:Concentration of alkanes in the chambers was monitored automatically every 15 min by on-line gas chromatography (Shimadzu GC-9A).Chromatography was performed at 200 deg C on a 2 m x 1/8" stainless steel column packed with GP 10% SP-2100 on Supelcoport 100/120 mesh with helium as the carrier gas. The alkanes were detected by a FID detector. Injector and detector temperatures were 250 deg C.

TEST ATMOSPHERE (if not tabulated)
- Particle size distribution:
- MMAD (Mass median aerodynamic diameter) / GSD (Geometric st. dev.):

Analytical verification of test atmosphere concentrations:

yes

Duration of exposure:

8 h

Concentrations:

n-C9: 5280*, 4438, 3560 and 2414 ppm
n-C10: 1369* ppm
n-C11: 442* ppm
n-C12: 142* ppm
n-C13: 41* ppm
Values marked * were the maximum achievable vapour concentration in air

No. of animals per sex per dose:

10 males

Control animals:

no

Details on study design:

- Duration of observation period following administration: Animals were exposed to at least the saturated vapour concentration (20 degrees C) for each test substance for 8 hr.
- Frequency of observations and weighing: During inhalation all animals were observd at 15 and 30 min intervals. For the first 8 hours after exposure all animals were observed hourly, then at 2 hour intervals during daytime for 14 days.
- Necropsy of survivors performed: yes, full gross necropsy on day 14
- Other examinations performed: clinical signs, histopathology, body weight, tissue weights of brain, lungs, heart, liver and kidney, the LC50 for n-nonane was calculated by probit analysis.

Sex:

male

Dose descriptor:

LC50

Effect level:

4 467 ppm

Based on:

test mat.

Remarks:

n-nonane

Exp. duration:

8 h

Remarks on result:

other: 23.4 mg/l

Sex:

male

Dose descriptor:

LC0

Effect level:

1 390 ppm

Based on:

test mat.

Remarks:

n-decane

Exp. duration:

8 h

Remarks on result:

other: 8.7 mg/l

Sex:

male

Dose descriptor:

LC0

Effect level:

442 ppm

Based on:

test mat.

Remarks:

n-undecane

Exp. duration:

8 h

Remarks on result:

other: 2.7 mg/l

Sex:

male

Dose descriptor:

LC0

Effect level:

142 ppm

Based on:

test mat.

Remarks:

n-dodecane

Exp. duration:

8 h

Remarks on result:

other: 0.99 mg/l

Sex:

male

Dose descriptor:

LC0

Effect level:

41 ppm

Based on:

test mat.

Remarks:

n-tridecane

Exp. duration:

8 h

Remarks on result:

other: 0.31 mg/l

Mortality:

n-nonane: 0/10, 1/10, 4/10, 9/10 at 2414, 3560, 4438 and 5280 ppm, respectively
n-decane, n-undecane, n-dodecane, n-tridecane: no mortality at maximum saturated vapour concentration

Clinical signs:

other: Tremor, spasms and limb paralysis were observed in rats treated with n-nonane. Most severe symptoms were observed in a high dose group. These symptoms were observed at 2 hours after the start of the exposure in the highest dose group. The length of time b

Body weight:

Not reported in the publication

Gross pathology:

No gross pathological changes were observed in the brain, lungs, heart, liver and kidneys following exposure to the n-C10 to n-C13 alkanes. In animals exposed to 4438 ppm of n-nonane the autopsy findings suggest that death was due to cardiopulmonary insufficiency. This may have been induced by the direct toxic effect of heart or lungs or by indirect effects by the central nervous system. In cerabellar cortex severe damage and extensive loss of purkinje neurons were demontrated.

Interpretation of results:

GHS criteria not met

Conclusions:

The acute inhalation LC50(rat, male) for n-nonane was 4467 ppm (23.4 mg/l) following 8-hr exposure.

Executive summary:

The acute inhalation toxicity of a series on C9-C13 n-alkanes were investigated in male SD rats following a single 8 -hr exposure to vapour. A calculated LC50 of 4467 ppm (23.4 mg/l) was determined for n-nonane; the 4 -hr LC50 value is likely to exceed this value. No mortality was recorded for the other test substances after exposure to the maximum achievable vapour concentration in air. Maximum saturated vapour concentration decreased in a predictable manner with increasing C-number.

The study was conducted for the read-across substance. This study is considered reliable since the publication contains sufficiently data for assessment.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Acute toxicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

2 920 mg/kg bw

Additional information

Oral exposure

In a guideline study of Sanders, A. (2012) (OECD 420 - Fixed dose method) without restrictions 1 female rat was gavaged with undiluted test substance at a dose level of 2000 mg/kg bw. Following a sighting study test at dose level of 2000 mg/kg, an additional four fasted female animals were given a single oral dose level of 2000 mg/kg bodyweight. Clinical signs and bodyweight development were monitored during the study. All animals were subjected to gross necropsy. The post exposure period was 14 days. There were no deaths observed during the study and no signs of toxicity were noted. All animals showed expected gains in bodyweight. No abnormalities were noted at necropsy. The acute median lethal dose (LD50) of the test item in female Wistar rat was estimated to be greater than 2000 mg/kg bodyweight.

 

As a conclusion, the results of the key study did not indicate this substance to be classified for acute toxicity via oral route.

Inhalation exposure

No valid data from renewable hydrocarbons of wood origin (naphtha type fraction) are available on acute inhalation toxicity. The UVCB substance is currently on pilot production phase and no representative sample is currently available.

The vapour pressure of the substance is measured to be 29.8 kPa at 40 deg. C (method DIN EN 13016-1) indicating that the substance is volatile at ambient T. Thus, inhalation exposure is likely. Based on the exposure assessment no high peak exposures are expected and the risks for acute effects are adequately controlled with the risk management measures presented for long-term effects (see CSR sections 9 & 10). The Oral toxicity key study conducted for the substance shows low acute toxicity (Sanders, A., 2012).

This UVCB substance is a complex mixture of hydrocarbons. When there is no data on the substance itself the read-across data was also used to avoid unnecessary animal testing. The read-across from fossil gasoline is justified because the toxicokinetics and toxicological properties of renewable gasoline are considered similar to fossil gasoline based on the similar composition and physical-chemical properties. The read-across justification and the data matrices are presented in the annex 1of the CSR.

Therefore, unnecessary animal testing was considered unjustified and the hazard evaluation via inhalation route is based on the main constituents of the substance. Inhalation toxicity of alkanes C9-C13 was studied by Nilson et. al.(1988). Male rats were exposed to inhalation of each alkane close to air saturation at 20 deg. C for 8 hours and observed for 14 days. In addition, exposure to several concentration of C9 alkane (nonane) was performed. A calculated LC₅₀of 4467 ppm (23.4 mg/l) was determined for n-nonane; the 4 -hr LC50 value is likely to exceed this value. No mortality was recorded for the other test substances after exposure to the maximum achievable vapour concentration in air.

 

Renewable hydrocarbons of wood origin (naphtha type fraction) contains also short chain (C4-C8) aliphatic hydrocarbons. Generally, these chemicals are highly volatile and inhalation is the primary route of exposure.Acute inhalation toxicity data in male and female rats for C5 hydrocarbons show LC50 values varying between 5.6 mg/L - 12.5 mg/L .Furthermore, LC50 values reported for C8 aliphatic hydrocarbon (2,2,4 trimethyl pentane) were greater than 14 mg/L and for C7 hydrocarbon (n-heptane) greater than 29.3 mg/L.

 

The aspiration property relates to the physico-chemical properties of the substance. Viscosity is a key parameter in determining aspiration hazards. Low viscosity substances have high potential to enter directly into trachea and lower air ways. The classification criteria for aspiration hazard of hydrocarbons refer to kinematic viscosity at 40 °C. The kinematic viscosity of the registering substance was 0.58 mm²/s measured in accordance with DIN EN ISO 3104. Hydrocarbons with kinematic viscosity lower than 20.55 mm²/s should be classified for aspiration hazard.

  

Short chain hydrocarbons, the most volatile components of the substance, have the potential to cause anaesthetic effects. Clinical signs indicative of transient CNS depression have been observed primarily with inhalation exposure at relatively high concentrations of C4 -C9 alkanes. Effects were resolved within 2 days post-exposure. As available information suggest that components of the substance cause central nervous system effects, renewable hydrocarbons of wood origin (naphtha type fraction) will be classified to hazard class STOT SE 3 H336.

 

Based on the above information there is no need to classify this substance based on lethal effects after inhalation exposure. However, this substance has potential to cause CNS depression based on the presence of volatile components of the substance, and the substance may cause aspiration hazard based on the kinematic viscosity.

Dermal exposure

 

The substance is a UVCB with varying composition. No representative sample is currently available from the substance, which is not yet at full scale production. The animal testing is concluded to be not warranted by the rules laid down in REACH Annex XI.

Based on the exposure assessment no high peak exposures are expected and the risks for acute effects are adequately controlled with the risk management measures presented for long-term effects. When there is no data on the substance itself the read-across data was also used to avoid unnecessary animal testing. The read-across from fossil gasoline is justified because the toxicokinetics and toxicological properties of renewable gasoline are considered similar to fossil gasoline based on the similar composition and physical-chemical properties. The read-across justification and the data matrices are presented in annex1of the CSR.

 

Acute dermal toxicity data for n-pentane in rabbits show an LD50 value of 3000 mg/kg bw. The dermal LD50 in rabbits was greater than 2920 mg/kg bw (multi-constituent subcategory, CAS 64742-49-0) and greater than 3160 mg/kg bw for iso-paraffins category (C7-C9) isoalkanes (CAS 90622-56-3), and 2,2,4-trimethylpentane ( CAS 540-84-1).

 

Based on this above information there is no need to classify this substance as having acute toxicity via dermal route.

Justification for selection of acute toxicity – oral endpoint
The reliable and guideline compliant study conducted for the substance

Justification for selection of acute toxicity – inhalation endpoint
No study conducted for the target substance. The selected study was conducted for the read-across substances (n-C9-C13 alkanes).

Justification for selection of acute toxicity – dermal endpoint
No specific study was selected since the hazard conclusion is based on the studies conducted for the most critical constituents of the substance.

Justification for classification or non-classification

The available data for renewable hydrocarbons of wood origin (naphtha type fraction) and from the read-across substance, indicate relatively low potential for acute toxicity. Based on the available acute toxicity data, the substance has not to be classified according to CLP Regulation 1272/2008 and Directive 67/548/EEC.

 

Classification and labelling for aspiration toxicity is based on the measured kinematic viscosity of a substance at 40 °C. The measured kinematic viscosity of the substance was 0.58 mm²/s. Based on this value the substance is classified for Asp. Tox 1 H304 according to CLP Regulation 1272/2008 and for Xn; R65 according to Directive 67/548/EEC.

This substance contains aliphatic hydrocarbons with carbon number C4-C12. Especially, the short chain hydrocarbons have been shown to cause transient sedation of the central nervous system after inhalation exposure. Based on these observations, the registering substance has to be classified to hazard class STOT SE 3 H336 according to CLP Regulation 1272/2008 and as R67 according to Directive 67/548/EEC.