Fatty acids, tall-oil, low-boiling

Endpoint summary

Description of key information

No acute toxicity data are available for Tall Oil Heads. However, good quality, reliable data are available for the two related substances Crude Tall Oil (CAS 8002-26-4) and Tall Oil Pitch (CAS 8016-81-7). A weight of evidence approach is therefore used to fill data gaps for Tall Oil Heads.
The key acute oral toxicity study for Crude Tall Oil gave an LD50 (oral) >2000 mg/kg bw (OECD 423, acute toxic class method) in rats (Wolf, 2005). There were no clinical signs or necropsy findings. For Tall Oil Pitch, an acute oral LD50 value >2000 in rats was determined in a study conducted in accordance with OECD 425 (up & down method) and in compliance with GLP (inveresk, 2002). There were no mortalities or other treatment-related findings in the study. It can therefore be concluded that the acute oral LD50 for Tall Oil Heads is >2000 mg/kg. 
The key acute dermal toxicity study for Crude Tall Oil gave an LD50 (dermal) >2000 mg/kg bw (OECD 402, limit test) in rats (Bernat, 2005). There were no clinical signs, signs of local irritation or necrospy findings. For Tall Oil Pitch, an acute dermal LD50 >2000 in rats was determined in a study carried out in accordance with OECD 402 and in compliance with GLP (ARC, 2005a). There were no mortalities, treatment-related systemic effects or local effects during the study. It can therefore be concluded that the acute dermal LD50 for Tall Oil Heads is >2000 mg/kg. 
No data are available for the inhalation route. 

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion

Dose descriptor:

LD50

Value:

2 000 mg/kg bw

Acute toxicity: via dermal route

Endpoint conclusion

Dose descriptor:

LD50

Value:

2 000 mg/kg bw

Additional information

No acute toxicity data are available for Tall Oil Heads. Acute oral and dermal toxicity studies are, however, available for the related substances Crude Tall Oil (CAS 8002 -26 -4) and Tall Oil Pitch (8016 -81 -7).

Tall Oil Heads is obtained by physical separation (distillation) of Crude Tall Oil, and the two substances are multiconstituent products containing the same constituents in different proportions (the main categories being fatty acids, resin acids, sterols and other neutrals). Tall Oil Heads contains a higher proportion of fatty acids and neutrals (excluding sterol-type constituents, which are not present in Tall Oil Heads), whereas Crude Tall Oil contains a higher proportion of resin acids and sterols.

Tall Oil Pitch is also a product of the distillation of Crude Tall Oil, and contains a higher proprtion of neutrals (sterols and others) than either Crude Tall Oil or Tall Oil Heads, as well as fatty acids, resin acids and a significant proportion of polymeric acids and neutrals.

The results of acute toxicity testing for the oral and dermal routes, using standard OECD test methods, indicated that both Crude Tall Oil and Tall Oil Pitch were not acutely harmful or toxic to rats, with LD₅₀ >2000 mg/kg in all cases. These two substances contain all constituents present in Tall Oil Heads at concentrations covering the range that is relevant for the registered substance. It is therefore considered appropriate to take a weight of evidence approach and conclude that the acute oral and dermal LD₅₀ values for Tall Oil Heads are also >2000 mg/kg.

Justification for classification or non-classification

On the basis of weight of evidence from related test materials, Tall Oil Heads does not meet the criteria for classification for acute toxicity via the oral and dermal routes according to EU Directive 67/548/EEC and Regulation 1272/2008.

No data are available for the inhalation route.