Octadecene, reaction products with hexadecene, hydrogenated

PBT assessment

PBT assessment: overall result

Reference

Name:

SynNova Base Oil™

Type of composition:

legal entity composition of the substance

State / form:

liquid

Reference substance:

SynNova Base Oil™

Reference substance:

SynNova Base Oil™

Reference substance:

SynNova Base Oil™

Reference substance:

SynNova 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 301 B / ISO 9439– Test 1: 61% after 28 days.  Did not pass 10 day window.

·       OECD 301 B / ISO 9439 – Test 2: 65% after 28 days.  Did not pass 10 day window.

·       OECD 301 B / ISO 9439 – Test 3: 66% after 28 days.  Did not pass 10 day window.

·       OECD 301 B / ISO 9439 – Test 4: 71% after 28 days.  Did not pass 10 day window.

·       OECD 301 B / ISO 9439 – Test 5: 78% after 28 days.  Did not pass 10 day window.

·       OECD 301 B / ISO 9439 – Test 6: 76% after 28 days.  Did not pass 10 day window.

·       OECD 301F Manometric Respirometry Test 1: 34% after 28 days. (ThODNH4).

·       OECD 301F Manometric Respirometry Test 2: 43.4% after 28 days. (ThODNH4).

·       Inherent Biodegradability: Modified MITI Test (III): 47.2% after 28 days. (ThODNH4

 

In all studies, the substance showed significant lag time for the first 7 days. Following that, significant biodegradation occurs. 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.

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 15.76 to 31.33.As the substance shows log Kow values 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, on the basis of the toxicity (or lack of) observed.

 

Two bioaccumulation studies in carp and rare minnow using the substances subject to registration have been conducted w

 

Toxicity

The substance is not toxic or 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 hydrocarbon UVCB, 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:              

The 24h, 48h, 72h and 96h LL50 value: > 100.0 mg/L

The 96h No-Observed Effect Loading Rate (NOELR): 100.0 mg/L

The 96h Lowest Observed Effect Loading Rate (LOELR): > 100.0 mg/L 

 

Chronic Fish Toxicity:           .

OECD 210

Hatching rate: NOEL =100mg/L; LOEL >100mg/L

Surviving rate after post-hatched: NOEL =100mg/L; LOEL >100mg/L

Cumulative abnormal rate: NOEL =100mg/L; LOEL >100mg/L

Cumulative mortality: NOEL =100mg/L; LOEL >100mg/L

Total length of surviving fish: NOEL =100mg/L; LOEL >100mg/L

Dry weight of surviving fish: NOEL =100mg/L; LOEL >100mg/L

OECD 212

Hatching rate: NOEL =100 mg/L; LOEL >100 mg/L

Surviving rate of larvae after post-hatched: NOEL =100 mg/L; LOEL >100 mg/L

Cumulative abnormal rate of embryos/larvae: NOEL =100 mg/L; LOEL >100 mg/L

Cumulative mortality of embryos/larvae: NOEL =100 mg/L; LOEL >100 mg/L

Total length of surviving larvae: NOEL =100 mg/L; LOEL >100 mg/L

Dry weight of surviving larvae: NOEL =100 mg/L; LOEL >100 mg/L

OECD 215

28 d - No Observed Effect Loading rate (NOEL) of juvenile growth test to Rare Minnow was the nominal loading rate of 100 mg/L (WAF), and the 28 d - Lowest Observed Effect Loading rate (LOEL) of juvenile growth test to Rare Minnow was greater than the nominal loading rate of 100 mg/L (WAF)

 

Acute Daphnia Toxicity:       

The 24h and 48h EL50 value: > 100.0 mg/L

The 48h EL100 value: > 100.0 mg/L

The 48h No-Observed Effect Loading Rate (NOELR): 100.0 mg/L

The 48h Lowest Observed Effect Loading Rate (LOELR): > 100.0 mg/L

 

Algal Toxicity:                       

Based on the nominal loading rate (WAF):

The 72h EbL50 value (biomass): > 100.0 mg/L

The 72h ErL50 value (growth rate): > 100.0 mg/L

The 72h EyC50 value (yield): > 100.0 mg/L

 The 72h No-Observed Effect Loading Rate (NOELR): 100.0 mg/L

The 72h Lowest Observed Effect Loading Rate (LOELR): > 100.0 mg/L 

 

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

 

Toxicity to terrestrial plants:  

EC50 for both germination and root elongation of Tomato, Cucumber, Lettuce, Mung bean, Cabbage, Watermelon, carrot, Mustard, Paddy and Corn were all greater than 1000 mg/L.

 

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