Registration Dossier

Administrative data

Workers - Hazard via inhalation route

Systemic effects

Long term exposure
Hazard assessment conclusion:
no hazard identified
Acute/short term exposure
Hazard assessment conclusion:
DNEL (Derived No Effect Level)
Value:
60 mg/m³
Most sensitive endpoint:
acute toxicity
DNEL related information
Overall assessment factor (AF):
3
Modified dose descriptor starting point:
NOAEC

Local effects

Long term exposure
Hazard assessment conclusion:
no hazard identified
Acute/short term exposure
Hazard assessment conclusion:
no hazard identified
DNEL related information

Workers - Hazard via dermal route

Systemic effects

Long term exposure
Hazard assessment conclusion:
no hazard identified
Acute/short term exposure
Hazard assessment conclusion:
no hazard identified
DNEL related information

Local effects

Long term exposure
Hazard assessment conclusion:
no hazard identified
Acute/short term exposure
Hazard assessment conclusion:
no hazard identified

Workers - Hazard for the eyes

Local effects

Hazard assessment conclusion:
no hazard identified

Additional information - workers

Poly alpha olefins and their respective structural analogues were not acutely toxic when administered via oral or dermal routes in several animal studies. Hence, these substances do not meet the classification and labelling criteria for acute oral or dermal toxicants as defined by EU DSD/DPD 67/548/EEC or CLP EU Regulation 1272/2008 (GHS aligned) criteria; therefore DNELs were not derived for these endpoints. 

The available acute inhalation toxicity data indicate that some poly alpha olefins (viscosity <15 cSt at 40°C, average carbon number <C-30) are acutely toxic in experimental animal studies with inhalation LC50 values consistent with EU labelling requirements for Xn/R20 (Directive 67/548 EEC) or Acute Tox. 4, H332 (Regulation 1272/2008); a DNEL is required for substances meeting these physico-chemical criteria or where experimental data indicate a LC50 below 5 mg/L. However test data available for other samples with kinematic viscosity >15 cSt at 40°C and an average C-number of 30 or higher return LC50 values in excess of 5 mg/L; no classification or DNEL is required for these substances.

The reported LC50 for dec-1-ene, dimers, hydrogenated is below 5 mg/L and it is therefore classified as R20, Harmful if inhaled in accordance with EU Dangerous Substance Directive 67/548/EEC and as a Category 4 inhalation hazard under EU CLP regulation 1272/2008 (GHS aligned). Derivation of acute inhalation DNELs for dec-1-ene, dimers, hydrogenated are discussed below under the Worker Acute Inhalation DNEL and General Population Acute Inhalation DNEL section.

Regulatory classification and labeling for aspiration toxicity relies on the measured or calculated kinematic viscosity of a substance at 40°C rather than results from toxicological studies with animals. The reported kinematic viscosity value for dec-1-ene dimers, hydrogenated is 5.1 cSt (Chevron Phillips Chemical Company, 2002). This value meets the criteria for classification as an aspiration toxicant under DSD (< 7 cSt) and EU CLP (< 20.5 cSt) regulations. Dec-1-ene dimers, hydrogenated is classified as Xn, R65, Harmful in accordance with EU Dangerous Substance Directive 67/548/EEC and as a Category 1 aspiration toxicant under EU CLP regulation 1272/2008 (GHS aligned). A DNEL is neither feasible nor appropriate for this endpoint.

A one-generation reproductive toxicity study in which Alkane 4 (a structural analogue to 1-decene trimer, hydrogenated and trimers) was administered via oral gavage to rats showed no adverse effects on fertility or development at the highest dose tested of 1000 mg/kg bw/day (Knox et al., 2007). Additionally, rats exposed to Ethylflo 166 (1-decene homopolymer hydrogenated) in utero were again treated with Ethyflo 166 for an additional 91 days beginning 22 days after birth (Daniel, 1994). There were no treatment-related effects reported at the highest dose tested (1000 mg/kg bw/day) in the parental generation, offspring at birth, or following 91 days of subsequent oral exposure. The weight of evidence presented by these studies suggests that poly alpha olefins, as a group, are unlikely to present a significant hazard potential to fertility and development; therefore no DNEL for reproductive toxicity is necessary. 

 

Worker Acute Inhalation DNEL

Information from studies using dec-1-ene dimer, hydrogenated, (summarised above) will form the basis for the DNEL. This indicates the occurrence of low levels of mortality in rats exposed for 4 hr to respirable concentrations of 0.76-1.81 mg/L test substance relative to an LC50 of 1.17 mg/L. Although the precise shape of the dose response curve at lower exposures is not known, it is not unreasonable to assume that no mortality would occur following exposure to respirable concentrations that were 10-fold lower.

An estimated NOAEC of 0.1 mg/L is therefore assumed for the acute inhalation toxicity of low molecular weight, low viscosity poly alpha olefins.

Modification of dose descriptor
Modify for differences in respiratory function for humans at rest and humans undertaking light work (following REACH TGD Chapter 8, Example A2) e.g.

Corrected NOAEC = 0.1 mg/L x 6.7/10 m3= 0.067 mg/L

Derive the Haber’s constant using the 4 hr data (using the corrected NOAEC of 0.067 mg/L) and the default regression coefficient (n) value of 3):

 

(c^n) x t = k

(0.067^3) x 4 = 1.20 x 10-3mg/L

 

Rearrange the modified Haber's law calculation and use the constant value to derive a concentration for the 15 minute (0.25 hour) time period:- 

 

(c^n) x t = k

 c = 3√ (k / t)

 c = 3√ (1.20 x 10-3/ 0.25)

 c = 0.1687 mg/L

 

The duration of exposure is appropriate for the assessment of human peak exposures.

 

Assessment factors1

 

Uncertainty

AF

Justification

Interspecies differences

1

Default (inhalation)

Intraspecies differences

3

Default (worker)

Establishment of NOAEC

1

Default (note: 10-fold adjustment applied already)

Duration of exposure

1

Default

Overall AF

3

 

1Assessment factors were based on ECETOC (2003)

DNELacuteInhalation: 0.1687 mg/L / 3 = 0.06 mg/L (60 mg/m3), 15 min TWA (worker)

General Population - Hazard via inhalation route

Systemic effects

Long term exposure
Hazard assessment conclusion:
no hazard identified
Acute/short term exposure
Hazard assessment conclusion:
DNEL (Derived No Effect Level)
Value:
50 mg/m³
Most sensitive endpoint:
acute toxicity
DNEL related information
Overall assessment factor (AF):
5
Modified dose descriptor starting point:
NOAEC

Local effects

Long term exposure
Hazard assessment conclusion:
no hazard identified
Acute/short term exposure
Hazard assessment conclusion:
no hazard identified
DNEL related information

General Population - Hazard via dermal route

Systemic effects

Long term exposure
Hazard assessment conclusion:
no hazard identified
Acute/short term exposure
Hazard assessment conclusion:
no hazard identified
DNEL related information

Local effects

Long term exposure
Hazard assessment conclusion:
no hazard identified
Acute/short term exposure
Hazard assessment conclusion:
no hazard identified

General Population - Hazard via oral route

Systemic effects

Long term exposure
Hazard assessment conclusion:
no hazard identified
Acute/short term exposure
Hazard assessment conclusion:
no hazard identified
DNEL related information

General Population - Hazard for the eyes

Local effects

Hazard assessment conclusion:
no hazard identified

Additional information - General Population

General Population Acute Inhalation DNEL

Dose descriptor

Information from studies performed using dec-1 -ene, dimers, hydrogenated indicates the occurrence of low levels of mortality in rats exposed for 4 hr to respirable concentrations of 0.76-1.81 mg/L test substance relative to an LC50 of 1.17 mg/L. Although the precise shape of the dose response curve at lower exposures is not known, it is not unreasonable to assume that no mortality would occur following exposure to respirable concentrations that were 10-fold lower.

 

A estimated NOAEC of 0.1 mg/L is therefore assumed for the acute inhalation toxicity of low molecular weight, low viscosity poly alpha olefins.

Modification of dose descriptor

Derive the Haber’s constant using the 4 hr data (using the NOAEC of 0.10 mg/L and the default regression coefficient (n) value of 3):

 

(c^n) x t = k

(0.10^3) x 4 = 4.00 x 10-3mg/L

 

Rearrange the modified Haber's law calculation and use the constant value to derive a concentration for the 15 minute (0.25 hour) time period: -

 

(c^n) x t = k

 c = 3√ (k / t)

 c = 3√ (4.00 x 10-3/ 0.25)

 c = 0.2520 mg/L

 

The duration of exposure is appropriate for the assessment of human peak exposures.

Assessment factors1

 

Uncertainty

 

AF

 

Justification

Interspecies differences

1

Default (inhalation)

Intraspecies differences

5

Default (general population)

Establishment of NOAEC

1

Default (note: 10-fold adjustment applied already)

Duration of exposure

1

Default

Overall AF

5

 

1Assessment factors were based on ECETOC (2003)

DNELacuteInhalation: 0.2520 mg/L / 5 = 0.05 mg/L (50 mg/m3), 15 min TWA (consumer)