Document b5xayDONbZoD1OMGGj93kJqGZ
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Pesticide* and You
P ip o 'c n y l BtchttcW August, 1990
chemicalWATCH
Mevinphos, continued from page 5
The acute toxicity of piperonyl bu negative for tumor formation, however,
mevinphos, including the potential for toxide is low, far lower than the active a variety of liver effects were observed.
groundwater contamination, mevin ingredients it accompanies. The acute At the lowest dose level, 30 m g /k g /
phos' persistence in die environment, oral LDm for rats is 11.5 g /k g and der day, liver weights were increased. At
and the need for crop rotational label mal absorption is limited. Poisoning the highest dose level, 500 m g/kg/d ay,
restrictions." Despite an expressed symptoms include anorexia, vomiting, there were increased liver weights and
concern for the significant number of diarrhea, intestinal inflammation, pul liver cell enlargement in males and
mevinphos poisonings, EPA "is reser monary hemorrhage, and perhaps mild females. Increased hepatic "focal mixed
ving consideration of special review for central nervous system depression. cells" and increased serum cholesterol
mevinphos until data become available that more clearly identify the risks posed by mevinphos use."
Repeated contact may cause slight skin irritation.
Rat metabolism studies submitted
were observed in females. In addition, increases in "pigment in follicles" and abnormal overgrowth of follicular cells
Sources:
to EPA and considered supplementary, of the thyroid were noted in both sexes.
1. Thomson, W.T. (1984). Agricultural Chemi demonstrate that piperonyl butoxide is
cals: Insecticides. Thomson Publications, Fresno, slowly absorbed from the gastrointesti
CA. 2.
U.S. EPA. (1988). Guidancefor the reregistnraal tract, with blood levels peaking after
tion o f pesticide products containing mevinphos as the 4-6 hours. Excretion occurs via the urine
active ingredient. Office of Pesticides Programs. and feces, peaking after 12-24 hours and
Washington, D C
24-48 hours, respectively. No evidence
Sources:
Gosselin, et aL 1984. Q inical Toxicology o f Commercial Products, Williams & Wilkins, Balti more, MD
Morgan, D.P. 1982. Recognition and Man agement of Pesticide Poisonings, 4th Edition. U s. Environmental Protection Agency, Washington,
Piperonyl Butoxide
of specific tissue retention is described, and additional testing to determine the structure of metabolites is required.
EPA's chronic toxicity database is
DC US.-EPA. 1988 Memorandum from John
Doherty to Phil Hutton Re: Piperonyl Butoxide chronic feeding/oncogenidty study. April 28, 1988. Office of Pesticides and Toxic Substances
Some pesticide formulations con tain pesticide synergists, in addition to the active ingredients and inerts. Syner
incomplete. A single teratology (birth defects) study was submitted by IBT laboratories and is considered invalid. Mutagenicity testing indicates piper
(OPTS), Washington, D C U5.-EPA . 1988. Memorandum from John
Doherty to Geraldine Werdig Re: Piperonyl Bu toxide metabolism and pharmacokinetic studies. February 25,1988. OPTS. Washington, D C
gists are chemical agents included to enhance the killing power of the active ingredients. Examples include piper onyl butoxide and N-Octyl bicyclohep-
onyl butoxide is not mutagenic with the exception of one study which yielded "equivocal" results. A rat reproduction study noted no effect on reproductive
US.-EPA. 1987. Memorandum from John Doherty to Joseph Tavano Re: Piperonyl Butoxide rat multi-generation reproduction study. October 30,1987. OPTS. Washington, D C
US.-EPA. 1985. Memorandum from Irving
tenedicarboximideCMGK264). A range of products from repellents to foggers to pediculiddes (lice killers) to garden sprays contain these commonly used
performance or pup development, however decreases in weight gain were observed at the highest dose level. A rat chronic feeding/cancer study was
Mauer to T. Gardner/P. Schroeder Re: Piperonyl Butoxide mutagenicity study. June 27, 1985. OPTS. Washington, D C
U.S.-EPA. 1988. Toxicology One-Liner. Office of Pestidde Programs. Washington, D C
synergists. They appear to increase the potency of pyrethrin, pyrethroids, rotenone, carbamates, and occasionally other classes of insecticides. Formula
chemBRIEFS-- ------------------------------
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Mercury in Paint, Partial Action
tions generally contain 5-20 times more synergist than active ingredient.
EPA announced the cancellation of may be sold. By July 23, 1990, the mercury for use in indoor latex paints. mercury registrants will label prod
Piperonyl butoxide inhibits impor The June29,1990action followed a case ucts for outdoor use only and deliver
tant liver enzym es responsible for of acrodynia, a severe form of mercury similar labels to paint manufacturers.
breakdown of some toxins, including poisoning, in a MI child whose home NCAMP Staff Toxicologist Catherine
pesticidal active ingredients. Specifi was painted in 1989 with paint contain Karr noted that the "action would re
cally, it has been shown to inhibit he ing 930ppm mercury, three times the duce an important component of pub
patic microsomal oxidase enzymes in legal level of 300ppm. In response, the lic exposure to hazardous levels of
laboratory rodents and by inference in federal Centers for Disease Control, MI mercury. However, in light of widely
humans. A related group of enzymes is Depts. of Agriculture and Health, and available alternatives, allowing con
inhibited in insects. Because these en NCAMP called for a ban on mercury tinued public exposure and environ
zymes act to detoxify many drugs and fungicides in paint (PAY, June 1990). mental degradation from mercury use
other chemicals, a heavy exposure to an Following negotiations between EPA in exterior paint is imprudent and in
insecticidal synergist may make a per and mercury registrants, it was agreed appropriate." EPA is requiring addi
son temporarily vulnerable to a variety that as of August 20,1990, manufactur tional data to assess the risk to painters
of toxic insults that would normally be ing interior paint containing mercury and residents from exterior paint con
easily tolerated.
will be unlawful, although all stocks taining mercury.