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

Table 62. Detection of nonionic detergent degradates in streams of the U.S. (Koplin, Furlong et al.
2002)
Chemical
Frequency
Detected
Maximum (μg/L)
Median
(μg/L)
4-nonylphenol 50.6 40 0.8
4-nonylphenol monoethoxylate 45.9 20 1
4-nonylphenol diethoxylate 36.5 9 1
4-octylphenol monoethoxylate 43.5 2 0.2
4-octylphenol diethoxylate 23.5 1 0.1
We are uncertain to what degree NP and NP-ethoxylates may or may not occur in carbaryl,
carbofuran, and methomyl product formulations and/or are added prior to application. Inert
ingredients are often not specified on product labels. Additionally, NP and NP-ethoxylates
represent a very small portion of the more than 4,000 inert ingredients that EPA permits for use
in pesticide formulations (EPA 2008). Many of these inerts are known to be hazardous in their
own right (e.g., xylene is a neurotoxin and coal tar is a known carcinogen). Several permitted
inerts are also registered a.i.s (e.g., copper, zinc, chloropictrin, chlorothalonil). Inerts can be
more than 50% of the mass of pesticide products, and millions of lbs of these products are
applied to the landscape each year (CDPR 2007). This equates to large contaminant loads of
inerts that may adversely affect salmon or their habitat. Uncertainty regarding exposure to these
ingredients will be qualitatively incorporated into our analysis.
Tank Mixtures
Several pesticide labels authorize the co-application of other pesticide products and other
materials in tank mixes, thereby increasing the likelihood of exposure to multiple chemical
stressors. For example, Sevin XLR Plus (EPA Reg. No. 264-333), which contains carbaryl,
specifies the product is compatible with a wide range of pesticides. The label indicates that
when used as a fruit thinner, Sevin XLR Plus may be mixed with other fruit thinners. Although
mixtures with other pesticides products are not specifically recommended on the Furadan LFR
label (EPA Reg. No. 279-3310, containing carbofuran), they are not prohibited. Furadan LFR
does specifically indicate that the product may be mixed with liquid fertilizer. Lannate SP (EPA
Reg. No. 352-342, containing methomyl) also provides instructions for tank mixing with other
products and identifies some tank mixes that are not compatible. These ingredients and the other
inert ingredients in these products are considered part of the action because they are authorized
by EPA’s approval of the FIFRA label. Exposure, and consequently risk associated with
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