Partially hydrogenated β-3,7,11-trimethyldodeca-1,3,6,10-tetraene, reaction products with linear C8-C16 alpha olefin, hydrogenated.

PBT assessment

PBT assessment: overall result

Reference

Reference 1

Name:

14 cSt Base Oil

Type of composition:

legal entity composition of the substance

State / form:

liquid

Reference substance:

14 cSt Base Oil

Reference substance:

14 cSt Base Oil

Reference 2

Name:

3 cSt Base Oil

Type of composition:

legal entity composition of the substance

State / form:

liquid

Reference substance:

3 cSt Base Oil

Reference substance:

3 cSt Base Oil

Reference substance:

3 cSt Base Oil

Reference 3

Name:

4 cSt Base Oil

Type of composition:

legal entity composition of the substance

State / form:

liquid

Reference substance:

4 cSt Base Oil

Reference substance:

4 cSt Base Oil

Reference substance:

4 cSt Base Oil

Reference 4

Name:

7 cSt Base Oil

Type of composition:

legal entity composition of the substance

State / form:

liquid

Reference substance:

7 cSt Base Oil

Reference substance:

7 cSt Base Oil

Reference substance:

7 cSt Base Oil

PBT status:

the substance is not PBT / vPvB

Justification:

Persistency

 

Degradation in the environment is a result of abiotic processes and biodegradation. The relative importance of these processes will depend upon the environmental compartment to which the individual components of the hydrocarbon UVCB substance partition. In general, abiotic processes are important in the atmosphere, whilst biodegradation is the principle mechanism of the breakdown of lower carbon chain length products in water and soil. Studies on direct phototransformation in water are not available but it is assumed on the basis of chemical structure and nature of use that direct photolysis is not expected to be a major degradation pathway for many of the hydrocarbon components in this UVCB substance. Likewise, hydrolysis is a reaction in which a water molecule or hydroxide ion substitutes for another atom or group of atoms present in a chemical resulting in a structural change of that chemical. Potentially hydrolyzable groups include alkyl halides, amides, carbamates, carboxylic acid esters and lactones, epoxides, phosphate esters, and sulfonic acid esters. The lack of a suitable leaving group renders compounds resistant to hydrolysis.

 

The chemical constituents that comprise the UVCB substance consist entirely of carbon and hydrogen and do not contain hydrolyzable groups. As such, they have a very low potential to hydrolyze. Therefore, this degradative process will not contribute to their removal from the environment.

 

Biodegradation studies on the substance are available for inspection as follows:

 

OECD 301B (in the presence of silica gel): 86.7% biodegradation in 28 days. 60% biodegradation was achieved at 8.9 days

OECD 301B (in the absence of silica gel): 78% in 28 days. 52% at the end of the 10-d window.

OECD 301F Manometric Respirometry Test (Chinese study): 49% after 28 days. Did not reach 60% at 10d-window.

OECD 301C Modified MITI Test (I) (Japanese study): 26% after 28 days.

OECD 302C Modified MITI Test (II) (Inherent degradation): 11.1% after 28 days.

 

It is considered on the basis of these results that the substance shows significant biodegradation, and can be considered to be biodegradable under normal conditions. The lighter fractions are expected to be readily biodegradable. Heavier fractions (majority by mass) are predicted to be inherently biodegradable. 

This conclusion is consistent with the established behaviour of analogue lubricant oil basestocks derived from petroleum, which have a very similar chemical composition apart from their much higher aromatic hydrocarbon content.

 

Bioaccumulation.

 

A full bioaccumulation study in accordance with Japanese Guidelines provided the following results:

 

Bioconcentration test

BCF

Level 1 (0.1 mg/L)

Peak 1: <63 L/kg

Peak 2: <2.0 L/kg

Peak 3: <29 L/kg

Level 2 (0.01 mg/L)

Peak 2: <10 L/kg

 

It was evaluated that a steady-state was reached within 28 days because all BCFs were less than 100 L/kg.

 

The substance is a hydrocarbon UVCB. Assessment using the US EPA On-Line EPI Suite™ KOWWIN version 1.68 model, the log Kow range is predicted to be 7.49 to 31.33.As the substance shows log Kow values in the main of > 10,it is proposed that the substance is not indicative of being potentially bioaccumulative, on the basis of the partition coefficient values observed.

The substance is, however, considered to be not bioavailable to aqueous organisms as demonstrated by the lack of toxicity. Furthermore, the high log Kow is considered to be more a consequence of poor water solubility than a lipophilic tendency and is considered to be not indicative of the tendency to bioaccumulate in lipid tissues of aquatic organisms. This is based in part on an evaluation of literature data which demonstrates a tendency for the Bioconcentration Factor (BCF) to decrease as Log Pow increases above 6. This assumption is further confirmed by the data set available on the substance which demonstrates that it is poorly absorbed, both on the basis of the toxicity (or lack of) observed, plus the absorption study which demonstrated the lack significant absorption in the rat.

 

The above opinion is also confirmed via use of the EPIWIN BCFBAF v3.01 for assessment of bioaccumulation. The smallest and largest theoretical molecular weight substances were assessed and all evaluated values are less that <2000, indicating that the substance is not proposed to be bioaccumulative.

 Evaluation of predicted molecular size data indicates that approximately 29% of the molecules are of a Dmax average of greater than 17 Å (1.7 nm) plus a molecular weight of greater than 700 (Da). 

 Taking into account the following:

 

·       The actual test data.

·       Demonstrated lack of absorption

·       Demonstrated lack of persistency

·       High predicted log Kow value.

·       Demonstrated lack of bioaccumulation potential

·       Molecular size data not being indicative of the propensity towards bioaccumulation.

 

 This indicates, within a weight of evidence approach and with expert judgment, that NovaSpec Renewable White Oil is deemed to not be bioaccumulative in aquatic organisms.

 

Toxicity

The substance is nottoxicor harmful. No evidence of general toxicity was noted in any of the mammalian studies conducted on the substance and its analogues. The substance is not acutely or chronically toxic, nor is it proposed to be carcinogenic. There are no mutagenic or reproductive toxicant activity ascribed to the substance. Furthermore, there is no evidence that, as a mineral hydrocarbon, the substance would be significantly absorbed via the oral, dermal or inhalation routes. With the exception of being an “aspiration hazard” (a physical effect based on viscosity), the substance is not classified.

Various studies have been conducted on Environmental Organisms with the following results:

Acute Fish Toxicity:              

 (1) - 96h-LL50 > 100mg/L nominal loading rate WAF

(2) - 96h-LL50 > 100mg/L nominal loading rate WAF

 

Chronic Fish Toxicity:           14d NOEL > 100mg/L nominal loading rate WAF.

 

Acute Daphnia Toxicity:       

 (1)- 48h-LL50 > 100mg/L nominal loading rate WAF

(2)- 48h-LL50 > 100mg/L nominal loading rate WAF

 

Chronic Daphnia Toxicity:     21d No Observed Effect Loading rate (NOEL)

NOEL for effects on reproduction: 100mg/L WAF

NOEL for effects on body length: 100mg/L WAF

NOEL for mortality of parent animals: 100mg/L WAF

Algal Toxicity:                       

72h EbC50 value (biomass): > 100 mg/L loading rate WAF

72h ErC50 value (growth rate): > 100 mg/L loading rate WAF

72h EyC50 value (yield): > 100 mg/L loading rate WAF

NOEC: 100 mg/L loading rate WAF

 

Inhibition of Bacterial Respiration: 3-Hour EC50 > 1000 mg/L. 3-hour; NOEC: 1000 mg/L.

 

Acute toxicity to Earthworms:         14d-LC0 1000mg/kg dry soil; 14d-LC50 > 1000mg/kg dry soil

 

There is no hazard proposed to any environmental organism at the limit of solubility in water.