GULFTENE C16-18 ISOMERISED OLEFINS - NICNAS

6.25% WAF 5 of the test animals had died, and the proportion of deaths increased at
successively larger WAF loadings till 40 (of the initial 60) animals (ie 66%) had died after 96
hours exposure. Trimmed Spearman-Karber analysis of the data furnished an LC50 of 53.8
g/L (WAF). As above since the C14-20 olefins are a component of the drilling mud,
assuming the toxicity of the mud is due to the olefin content, the results imply that the LC50
for the olefins may be significantly lower than 53.8 g/L. This result may also indicate that the
C14-20 olefins are more toxic to this species of marine invertebrate than the C16-18 olefins.
Copepod (Crustacean) Acute Toxicity Test (Environment & Resource Technology Ltd
1995)
A test report on the effect of C16-18 alpha olefins isomerised, to the marine copepod Acartia
tonsa (a herbivore) was submitted. This study was conducted in accordance with a US EPA
test protocol (Standard Operating Procedure 106 (US EPA 1985) using WAF of the test
substance prepared with nominal loadings of 1 000, 1 800, 3 200, 5 600 and 10 000 mg/L in
sea water. The tests at each loading were conducted in duplicate with four replicate control
tests (no test substance), with approximately 10 adult animals per test vessel. The test
duration was 48 hours during which the animals were exposed to dim continuous
illumination, while the temperature was maintained at 21±0.2°C and the pH and dissolved
oxygen levels were 8.1±0.03 and 94% saturation, respectively. The pattern of animal
mortality in this test was unusual in that zero mortality was observed at the highest nominal
WAF loading (10 g/L), but up to 25% mortality occurred at the lower loadings, with no
discernible pattern. This behaviour was exhibited by both sets of test replicates, while no
deaths were recorded in any of the four controls. The results could not be analysed by the
usual statistical methods, but it was concluded that the 48 hour LL50 was in excess of a WAF
loading of 10 000 mg/L, and consequently the material can be considered to be non toxic to
this species up to the limits of its water solubility. No explanation for the deaths observed at
the lower WAF loadings was offered in the report.
Amphipod (Crustacean) Acute Toxicity Test (Environment & Resource Technology Ltd
1995)
The effect of C16-18 alpha olefins, isomerised to the marine amphipod, Corophium volutator
(a benthic dwelling sediment reworker) was conducted in accordance with (US EPA 1985)
test protocols for toxicity testing of chemicals to marine organisms. The test is performed by
placing the test animals in beakers containing sediment, previously loaded with quantities of
the test substance. In the present test, samples of sediment taken from the area in which the
test animals originated, were prepared with nominal loadings of 100, 1 000, 3 200, 10 000
and 32 000 mg/kg of the test substance, on a wet weight basis. Around 100 grams of each
preparation were placed in individual one litre tall form beakers and sea water added to bring
the final volume to one litre. The tests at each loading were conducted in triplicate with five
replicate controls with approximately 20 adult animals per test vessel. The test duration was
10 days, during which the animals were exposed to constant dim illumination, while the
temperature was maintained at 18±1.5°C. The pH was 8.1±0.03 and dissolved oxygen levels
maintained through continuous aeration were between 92 and 98% saturation, respectively.
At the end of the 10-day test period, the sediment was sifted and the surviving animals
counted (it was assumed that dead animals would have decomposed or have been consumed
by the survivors). The data were analysed using the (US EPA 1991) method, and the 10-day
LL50 was determined as 1 250 mg/kg. It is to be noted that this result expresses the nominal
FULL PUBLIC REPORT 26 April 2000
NA/713 Page 83 of 100