United States
Environmental Protection
Agency
Office of Water
4601
EPA 811-F-95-003wT
October 1995
&EPA
National Primary Drinking
Water Regulations
Oxamyl (Vydate)
CHEMICAL/ PHYSICAL PROPERTIES
CAS NUMBER: 23135-22-0
COLOR/ FORM/ODOR:
White crystals with slight sulfurous
• odor.
M.P.: 100-192° C, different crystalline
form at 108-110"C
VAPOR PRESSURE: N/A
OCTANOL/WATER PARTITION (Kow):
DENSITY/SPEC. GRAV.: N/A
N/A
SOLUBILITY: 280 g/L of water at 25° C;
Very soluble in water
SOIL SORPTION COEFFICIENT: N/A
ODOR/TASTE THRESHOLDS: N/A
BlOCONCENTRATION FACTOR: N/A
HENRY'S LAW COEFFICIENT: N/A
TRADE NAMES/SYNONYMS:
Vydate K; Thioxamyl; Dioxamyl; DPX
1410; Dupont 1410; Methyl N'.N'-
dimethyl-N-((methylcarbamoyl)oxy)-
1-thiooxamimidate
DRINKING WATER STANDARDS
MCLG: 0.2 mg/L
MCL: 0.2 mg/L
HAL(child): 1- to 10-day: 0.2 mg/L
Longer-term: 0.2 mg/L
HEALTH EFFECTS SUMMARY
Acute: EPA has found oxamyl to potentially cause the
following health effects from acute exposures at levels
above the MCL: tremors, salivation and tearing due to
cholinesterase inhibition.
Drinking water levels which are considered "safe" for
short-term exposures: For a 10-kg (22 Ib.) child consum-
ing 1 liter of water per day, up to a 7-year exposure to 0.2
mg/L.
Chronic: Oxamyl has the potential to cause the
following health effects from long-term exposures at
levels above the MCL: decreased body weight.
Cancer: There is no evidence that oxamyl has the
potential to cause cancer from a lifetime exposure in
drinking water.
RELEASE PATTERNS
Oxamyl is released directly to the environment in its
use as an insecticide and during its manufacture, han-
dling and storage.
Since oxamyl is not a listed chemical in the Toxics
Release Inventory, data on releases during its manufac-
ture and handling are not available.
ENVIRONMENTAL FATE
Oxamyl is highly soluble in water, and is relatively
stable in aqueous solutions at acidic pH. It hydrolyzes
and photodegrades rapidly to an oximino compound.
Biodegradation is also rapid in soils under both aerobic
and anaerobic conditions. While laboratory studies have
found oxamyl to be mobile in soils, field data indicates
only limited mobility, most likely due to rapid biodegrada-
tion.
Bioconcentration is not expected as oxamyl is rapidly
absorbed, metabolized and eliminated in toxicological
tests. However, some accumulation has been noted in
the skin and hair of rodents, so accumulation may occur
in species that do not readily metabolize the compound.
Exposure data are limited, but oxamyl has been found
USAGE PATTERNS -m drinking water at levels averaging 5 percent of the
Oxamyl is widely used for control of insects, mites and MCL.
nematodes on field crops, fruits and ornamentals. The
•ajority of oxamyl is applied to apples (36 percent),
potatoes (33 percent), and tomatoes (20 percent).
EPA estimated that 400,000 Ibs. of oxamyl were pro-
duced in the US in 1982.
October 1995
Technical Version
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OTHER REGULATORY INFORMATION
MONITORING:
FOR GROUND/SURFACE WATER SOURCES:
INITIAL FREQUENCY- 4 quarterly samples every 3 years
REPEAT FREQUENCY- If no detections during initial round:
2 quarterly per year if serving >3300 persons;
1 sample per 3 years for smaller systems
TRIGGERS - Return to Initial Freq. if detect at > 0.002 mg/L
ANALYSIS:
REFERENCE SOURCE METHOD NUMBERS
EPA 600/4-88-039 531.1
Standard Methods 6610
TREATMENT:
BEST AVAILABLE TECHNOLOGIES
Granular Activated Charcoal
FOR ADDITIONAL INFORMATION:
* EPA can provide further regulatory and other general information:
• EPA Safe Drinking Water Hotline - 800/426-4791
* Other sources of lexicological and environmental fate data include:
• Toxic Substance Control Act Information Line - 202/554-1404
• Toxics Release Inventory, National Library of Medicine - 301/496-6531
• Agency for Toxic Substances and Disease Registry - 404/639-6000
• National Pesticide Hotline - 800/858-7378
October 1995
Technical Version
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