Dichlorvos (DDVP) Risk Characterization Document - California ...

Table 9.
The no-observed-effect levels (NOELs) and lowest-observed-effect levels (LOELs) of DDVP from chronic studies.
Plasma ChE a RBC ChE a Brain ChE a Other Effects
Species Route a Duration a NOEL LOEL % C NOEL LOEL % C NOEL LOEL % C NOEL LOEL Effects Ref. b
(mg/kg-day) (mg/kg-day) (mg/kg-day) (mg/kg-day)
Rat diet 7d/wx80w - - - - - - - 7.5 15 reduced body weight 1
Rat diet 7d/wx2y 0.13 1.2 79-95% 0.13 1.2 78-92% >8.0 - 1.2 8.0 hepatocyte degeneration 2
at 2y
at 2y
Rat gavage 5d/wx2y - - - - - - oncogenic risk c mononuclear leukemia 3*
and other tumors
Rat water 7d/wx2y - - - - - - 14 28 reduced body weight 4
in males
Mouse gavage 5d/wx2y - - - - - - oncogenic risk forestomach tumors 3*
Mouse diet 7d/wx80w - - - - - - 45 90 reduced body weight 5
Dog capsule 7d/wx1y 0.05 1.0 46% 0.05 1.0 54% 0.05 1.0 78% 1.0 3.0 emesis, salivation, ataxia 6*
at 52w at 52w at 52w
Dog diet 7d/wx2y 0.01 0.09 64-86% 0.01 0.09 49-60% >8.9 - no effects 0.09 0.9 hepatocyte degeneration 7
at 1-12w at 4-24w
Rat inhal 23h/d 0.05 0.5 76-84% 0.05 0.5 69-72% 0.05 0.5 90% 0.5 4.6 reduced body weight 8
x7d/wx2y at 104w at 104w at 104w
a/
b/
c/
Abbreviations: ChE= cholinesterase, RBC= erythrocyte, inhal= inhalation, h= hours, d= days, w= weeks, y= years, % C= % of control values at the LOEL,
-= data not available.
* after the reference number indicates the study was acceptable to DPR according to FIFRA guidelines. References: 1. NCI, 1977a; 2. Witherup et al.,
1967; 3. Chan, 1989; 4. Enomoto, 1978; 5. NCI, 1977b; 6. Markiewicz, 1990; 7. Jolley et al., 1967; 8. Blair et al., 1974.
Oncogenic effects are assumed to have no threshold levels, and they are evaluated by the calculation of potency factors.
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