Comparison of test methods and early toxicity characterization for five dispersants.
The acute toxicities of a commercial dispersant (Corexit 9527) and four experimental dispersant formulations were evaluated using the 96-h mysid (Mysidopsis bahia) test and two rapid screening tests, Microtox and the Mysid IQ Toxicity Test. During 96-h toxicity tests, survival observations were recorded at 3, 6, 9, 12, and 24 h to document mortalities from short-term exposures more consistent with field exposure times and more approximate to exposure times used in Microtox and the Mysid IQ Toxicity Test. At nominal concentrations (6.25 and 12.5 mg/liter) and exposure times (3-24 h) near the upper range of predicted field conditions, mysid mortalities were </=5% for all test materials. Microtox and Mysid IQ Toxicity Test were evaluated for their ability to differentiate test materials compared with that of the 96-h mysid test. Dispersant formulations were ranked by relative toxicities based on LC50 or EC50 values and ranks compared among test methods. Microtox ranked the test materials similar to the 96-h mysid test. Ranks from the Mysid IQ Toxicity Test were dissimilar to those of the other tests. Early mortality observations during 96-h tests did not provide a better basis for comparing results of the rapid screening tests.
George-Ares
A
A
Exxon Biomedical Sciences, Inc., Mettlers Road CN 2350, East Millstone, New Jersey, 08875-2350, USA.
Clark
J R
JR
Biddinger
G R
GR
Hinman
M L
ML
D000818:Animals; D003445:Crustacea; D007928:Lethal Dose 50; D008055:Lipids; D013056:Spectrophotometry, Ultraviolet; D013501:Surface-Active Agents / Q000633:toxicity*; D013997:Time Factors; D018675:Toxicity Tests
D008055:Lipids; D013501:Surface-Active Agents; C021984:corexit 9527