Carbaryl, Carbofuran, and Methomyl - National Marine Fisheries ...

formulations were presented for bluegill sunfish (L. macrochirus) and rainbow trout (O. mykiss).
A single test on rainbow trout was conducted using the formulation Furadan 75WP with a
reported LC50 of 458 μg/L. LC50s for rainbow trout tested with technical carbofuran ranged
from 362-600 μg /L. A number of different formulations (Furadan 4F, Furadan 10G, Furadan
50WP and Furadan 75WP) were tested with bluegill sunfish. LC50s ranged from 240-488 μg
carbofuran/L. LC50s for bluegill sunfish tested with technical carbofuran ranged from 88-126
μg a.i/L. Only one formulation test for freshwater invertebrates was reported. D. magna
exposed to “5G” had a survival EC50 of 41 μg /L. Tests with D. magna on technical carbofuran
produced survival EC50s of 29-38.6 μg /L. The estuarine fish Atlantic silverside (Mendia
menidia) was tested in two formulations, Furadan 4F and Furadan 15G. LC50s from these tests
were 36 μg a.i./L and 64 μg a.i./L, respectively. A test with technical grade on the same species
produced an LC50 of 33 μg a.i./L. (95% CI 27-41 μg a.i./L). The estuarine/marine invertebrate
pink shrimp was tested both in a formulation (Furadan 15G) EC50 13.3 μg a.i./L and with
technical (EC50s 4.6-7.3 μg a.i./L, n=2). Based on these data, there is no indication that the
carbofuran formulations tested are more toxic than the a.i. on survival as an endpoint. No long
term studies, such as life cycle studies, with formulations were reported for either fish or
invertebrates.
The methomyl BE (EPA 2003a) and Science Chapter for the RED (EPA 1998c) both reported
toxicity data for a 24% formulation and a 29% formulation for both fish and aquatic
invertebrates. In addition, the BE reported some toxicity data for a 30% formulation. While it is
difficult to make a definitive comparison given the structure of the data, the 24% formulation
appears more toxic to both fish and invertebrates. Neither the toxicity section of the BE nor the
use characterization in the Science Chapter list specific products. Thus, we cannot crossreference
the data to a product or determine if it is a currently registered product.
Identified data gaps and uncertainties of carbofuran’s, carbaryl’s and methomyl’s
toxicity information presented in BEs and REDs:
Overall, data provided in the BEs and their Science Chapters were insufficient to allow a
thorough evaluation of all identified assessment endpoints and measures considered by NMFS.
The Data Evaluation Reviews (DERs) or the original studies may have helped reduce some of
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