Eucalyptus globulus, ext.

Short-term toxicity to fish

Description of key information

OECD Guideline 203, GLP, Weight of Evidence, validity 1:
Eucalyptus oil globulus 96h-LL50 = 42 mg/L
Eucalyptus crude oil 96h-LL50 = 18 mg/L

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

18 mg/L

Additional information

Based on a weight of evidence approach, the acute toxicity of Eucalyptus oil to fish can be estimated, in a first step, using adequate toxicity data of major constituents, greater than 10% in the mixture. Three constituents were considered, representing 90% of the mixture. To obtain a worst case estimation, the worst case percentages of each constituent were taken into account based on the individual toxicities of these compounds. These data are summarized in the table below:

Constituents	Worst-case composition	Acute fish 96h-LC50, mg/L	Reference in IUCLID 6
Cineol 1,8	55%	57	1,8-Cineol, 470-82-6, Short-term toxicity to fish, Goodband, 2012, RS, W
Limonene	12%	0.71	d-limonene, 5989-27-5, Short-term toxicity to fish, Broderius, 1990, RS, W
Pinene α	23%	0.28	alpha-pinene, 7785-70-8, Short-term toxicity to fish, Broderius, 1990, RS, W

 

The acute toxicity of Eucalyptus oil to fish was estimated using the following additivity formula, as recommended in the Regulation (EC) No 1272/2008:

∑ Ci / L(E)C50m = ∑ (Ci / L(E)C50i)

Where,

Ci = concentration of component i (weight percentage);

L(E)C50i = LC50 or EC50 for component i, in mg/L;

L(E)C50m = L(E)C50 of the part of the mixture with test data;

 

Based on data presented above, the 96h-LC50m value for Eucalyptus oil was estimated to be 0.90 mg/L for fish for a worst case typical mixture, corresponding to an Aquatic Acute 1 classification (according to the 2nd ATP of the Regulation (EC) No 1272/2008).

However, this constituent approach was considered as a worst case. To prove that Eucalyptus oil is not classified as Aquatic Acute 1 and as fish was considered as the most sensitive species in acute conditions, two experimental acute fish studies were performed for two worst case typical mixtures of Eucalyptus oil (one mixture containing the greater percentage of Limonene: Eucalyptus crude oil, and the other the greater percentage of Pinene α: Eucalyptus oil globulus).

As a validation that additivity approach is a real wost case, the experimental studies show 96h-LL50 of 18mg/L and 42 mg/L for both Eucalyptus crude oil and Eucalyptus oil globulus respectively. Therefore, the Aquatic Acute 1 classification should no longer be considered.