Octacos-1-ene

Toxicological Summary

Workers - Hazard via inhalation route

Systemic effects

Acute/short term exposure

DNEL related information

Local effects

Acute/short term exposure

DNEL related information

Workers - Hazard via dermal route

Systemic effects

Acute/short term exposure

DNEL related information

Additional information - workers

Linear alpha olefins were not acutely toxic when administered via oral, dermal, or inhalation routes in several animal studies. Hence, these substances do not meet the classification and labelling criteria for acute oral, dermal, or inhalation toxicants according to EU DSD/DPD 67/548/EEC or CLP EU Regulation 1272/2008 (GHS aligned); therefore short-term DNELs were not derived for these endpoints.

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. All linear alpha olefins which exist as liquids at 40°C are classified as aspiration hazards because their respective kinematic viscosities are below the discriminating thresholds established for classification and labelling set forth in EU DSD/DPD 67/548/EEC (< 7 mm²/sec) or CLP EU Regulation 1272/2008 (GHS aligned)(< 20.5 mm²/sec). There are no kinematic viscosity data available for octacos-1-ene. Octacos-1-ene exists as a solid substance at room temperature and is expected to have a melting point > 38 °C based on read across to docos-1-ene (Lide, 2008). The physicochemical properties of this substance preclude it from being considered as a potential aspiration toxicant. A DNEL is neither feasible nor appropriate for this endpoint.

 

Two developmental/reproductive screening studies were available for linear alpha olefins (a 41-55 day study with hex-1-ene (Daniel, 1999) and a 43-51 day study with tetradec-1-ene (Daniel, 1999), both of which reported no treatment-related adverse effects on fertility and developmental parameters at the highest dose tested (1000 mg/kg bw/day). Results from developmental/reproductive screening studies conducted on isomerised olefin substances such as octadecene (Thorsrud, 2003) and C6, alkenes (Thorsrud, 2003) were also negative for effects on fertility and development. The weight of evidence presented by these studies suggests that higher olefin substances, as a group, are unlikely to present a significant hazard potential to fertility and development. However, these studies do not meet standard REACH information requirements for this endpoint since the studies do not fully assess all phases of the reproductive cycle (e.g. oestrus cyclicity, sperm quality, post weaning development, maturation and the reproductive capacity of the offspring). Therefore, these studies cannot be substituted for a full teratogenicity study (OECD 414) or two-generation study (OECD 416). Further testing on oct-1-ene (CAS RN 111-66 -0), a linear alpha olefin, has been proposed to address these outstanding toxicological endpoint data gaps for all higher olefins.

 

Workers

A worker-DNEL_{long-term for dermal route-systemic} and worker-DNEL_{long term for inhalation route-systemic} were not derived for linear alpha olefins because no adverse findings relevant to human health risk assessment were found in a 90-day inhalation repeated dose study with hex-1-ene (Bennick et al., 1984) and a combined repeated dose/ reproductive/developmental screening study with tetradec-1-ene (Daniel, 1995). No relevant adverse effects were observed at the highest dose tested in each study (3000 ppm corresponding with 10.3 mg/L hex-1-ene and 1000 mg/kg bw/day tetradec-1-ene, respectively).  Results from an additional good quality and high reliability 90-day repeated dose study with multiple carbon number isomerised olefin, alkenes, C20-24 (Brooker, 1999), also reported no adverse findings relevant to human health at the limit dose of 1000 mg/kg bw/day. The weight of evidence presented by these study results indicates that higher olefins, as a class, possess an inherently low hazard potential with regard to human health. Therefore, derivation of long-term DNELs is unnecessary. A worker-DNEL_{long-term for oral route-systemic}was not calculated for linear alpha olefins because oral exposure to these substances was not considered a relevant route of exposure for a worker population.

 

General Population - Hazard via inhalation route

Systemic effects

Acute/short term exposure

DNEL related information

Local effects

Acute/short term exposure

DNEL related information

General Population - Hazard via dermal route

Systemic effects

Acute/short term exposure

DNEL related information

General Population - Hazard via oral route

Systemic effects

Acute/short term exposure

DNEL related information

Additional information - General Population

General Population

General population DNELs for acute effects were not derived because no relevant hazard was apparent from the available toxicological data.

A general population-DNEL_{long-term for oral route-systemic}, general population-DNEL_{long-term for dermal route-systemic}, and general population-DNEL_{long term for inhalation route-systemic}were not derived for linear alpha olefins because no adverse findings relevant to human health risk assessment were found in a 90-day inhalation repeated dose study with hex-1-ene (Bennick et al., 1984) and a combined repeated dose/ reproductive/developmental screening study with tetradec-1-ene (Daniel, 1995). No relevant adverse effects were observed at the highest dose tested in each study (3000 ppm corresponding with 10.3 mg/L hex-1-ene and 1000 mg/kg bw/day tetradec-1-ene, respectively).  Results from an additional good quality and high reliability 90-day repeated dose study with multiple carbon number isomerised olefins, alkenes, C20-24 (Brooker, 1999), also reported no adverse findings relevant to human health at the limit dose of 1000 mg/kg bw/day. The weight of evidence presented by these study results indicates that higher olefins, as a class, possess an inherently low hazard potential with regard to human health. Therefore, derivation of long-term DNELs is unnecessary.