Sodium Methyldithiocarb - Chemical Profile 10/84
CHEMICAL NAME: Sodium N-methyldithiocarbamate (56)
TRADE NAME(S): Vapam, VPM (48)
FORMULATION(S): Aqueous solutions (48)
TYPE: Soil fumigant-nematicide-fungicide
BASIC PRODUCER(S): Stauffer Chemical Co.
Nyala Farm Road
Westport, CT 06880
STATUS: General use
PRINCIPAL USES: Control of soil-borne species of nematodes and some
fungus on a variety of crops (48).
General purpose soil fumigant. Highly effective in control of
weeds and weed seeds, nematodes, and soil fungi. Penetration and
effectiveness is improved somewhat by a water seal although this is not
To be developed.
II. PHYSICAL PROPERTIES
MOLECULAR FORMULA: C2 H4 N Na S2 (26)
MOLECULAR WEIGHT: 129.2 (26)
PHYSICAL STATE: Colorless crystalline dihydrate (pure compound)
SOLUBILITY: 722 g dihydrate/l water at 20 C (pure compound)
III. HEALTH HAZARD INFORMATION
OSHA STANDARD: NA
NIOSH RECOMMENDED LIMIT: NA
ACGIH RECOMMENDED LIMIT: NA
A. ACUTE TOXICITY
DERMAL: LD50 = 800 mg/kg (rabbit); irritant (26).
LD50 = 1300 mg/kg (rabbit, Vapam Soil Fumigant
ORAL: LD50 = 820 mg/kg (male rat) (26)
LD50 = 1700 mg/kg (female rat, Vapam Soil Fumigant
LD50 = 1800 mg/kg (male rat, Vapam Soil Fumigant
INHALATION: The acute inhalation LC50 is greater than 4.7
mg/l in both male and female rats. A single 4-hour inhalation exposure
of 4.7 mg/l (greater than 85 percent respirable) produced decreased
physical activity and blood-like stains about the face in female rats.
A single 4-hour inhalation exposure of 4.7 mg/l (greater than 85 percent
respirable) produced decreased physical activity, dyspnea, blood-like
stains about the face, 6 to 14 percent decrease in mean body weights
and 10 percent mortality in male rats (Vapam Soil Fumigant Solution)
EYES: Mild irritant to rabbit eyes (Vapam Soil Fumigant
B. SUBACUTE AND CHRONIC TOXICITY:
To be developed.
IV. ENVIRONMENTAL CONSIDERATIONS
Fumes toxic to living plants (48).
This product is toxic to fish. Keep out of lakes, streams and
ponds. Do not contaminate water sources by cleaning equipment or
disposing of wastes (29i).
V. EMERGENCY AND FIRST AID PROCEDURES
The chemical information provided below has been condensed
from original source documents, primarily from "Recognition and
Management of Pesticide Poisonings", 3rd ed. by Donald P. Morgan,
which have been footnoted. This information has been provided in
this form for your convenience and general guidance only. In
specific cases, further consultation and reference may be required
and is recommended. This information is not intended as a sub-
stitute for a more exhaustive review of the literature nor for the
judgement of a physician or other trained professional.
If poisoning is suspected, do not wait for symptoms to develop.
Contact a physician, the nearest hospital, or the nearest Poison
SKIN CONTACT: Immediately remove contaminated clothing wiping
away excess material from the skin. Under a safety shower, flush all
affected areas with large amounts of water for at least 15 minutes. Do
not attempt to neutralize with chemical agents. Obtain medical advice
INGESTION: Immediately dilute the swallowed material by giving
large quantities of water. Induce vomiting by gagging the victim with
a blunt object placed on the back of the victim's tongue. Continue
fluid administration until vomitus is clear. Never give anything by
mouth to an unconscious person. Call a physician or the nearest Poison
Control Center immediately (29i).
INHALATION: Remove from contaminated atmosphere. If breathing
has ceased, clear the victim's airway and start mouth-to-mouth
artificial respiration, which may be supplemented by the use of a
bag-mask respirator or a manually-triggered, oxygen supply capable of
delivering one liter/second or more. If the victim is breathing,
oxygen may be delivered from a demand-type or continuous-flow
inhalator, preferably with a physician's advice (29i).
EYE CONTACT: Immediately flush the eyes with large quantities of
running water for a minimum of 15 minutes. Hold the eyelids apart
during the flushing to ensure rinsing of the entire surface of the eye
and lids with water. Do not attempt to neutralize with chemical
agents. Obtain medical attention as soon as possible. Oils or
ointments should not be used. Continue the flushing for an additional
15 minutes if the physician is not immediately available (29i).
VI. FIRE AND EXPLOSION INFORMATION
GENERAL: This material is considered noncombustible. However, under
fire conditions it may decompose to give off toxic oxides of nitrogen
and sulfur. Vapors are extremely irritating to the respiratory tract
and may cause breathing difficulty and pulmonary edema. Symptoms may
be delayed several hours or longer depending upon exposure.
As in any fire, prevent human exposure to fire, smoke, fumes or
products of combustion. Evacuate nonessential personnel from the fire
area. When there is a potential for exposure to smoke, fumes, products
of combustion, etc., firefighters should wear full-face, self-contained
breathing apparatus and impervious clothing such as gloves, hoods,
suits and rubber boots. Use of contaminated buildings, area and
equipment must be prevented until they are properly decontaminated
EXTINGUISHER TYPE: Use standard firefighting techniques in
extinguishing fires involving this material - use water, dry chemicals,
foam or carbon dioxide. If drums are not leaking, keep cooled with a
water spray. High pressure water hose may spread product from broken
containers increasing contamination hazards (29i).
Corrosive to brass and copper (48).
Upon dilution with water or on heating, the material decomposes
and forms methyl isothiocyanate and hydrogen sulfide, both highly
poisonous. Use promptly after mixing with water. Do not allow
solution to stand. This material is not compatible with acidic
VIII. PROTECTIVE MEASURES
STORAGE AND HANDLING: Stable in concentrated solution but unstable on
dilution. Avoid contact with skin and eyes (56).
Do not store below 0 F. Product crystallizes at lower
temperatures. Warm or store at higher temperatures and mix to
redissolve crystals and assure uniformity before use (29g).
Do not store near feed or food (29g).
PROTECTIVE CLOTHING: Skin contact with liquid or its aerosol must be
prevented through the use of impervious clothing, gloves and footwear,
selected with regard for use condition exposure potential. Eye contact
with liquid or its aerosol should be avoided through the use of
chemical safety glasses, goggles or face shield, selected with regard
for use condition exposure potential (29i).
PROTECTIVE EQUIPMENT: When applying in enclosed areas wear a mask or
respirator of a type approved by the U.S. Bureau of Mines for Vapam
IX. PROCEDURES FOR SPILLS AND LEAKS
IN CASE OF EMERGENCY, CALL, DAY OR NIGHT
PESTICIDE TEAM SAFETY NETWORK/CHEMTREC
Make sure all personnel involved in the spill cleanup follow good
industrial hygiene practices.
Small spills can be handled routinely. Use adequate ventilation
and wear an air-supplied respirator to prevent inhalation. Wear
suitable protective clothing to prevent skin and eye contact. Use the
1. Spread a suitable absorbent such as clay, sawdust or kitty litter
on the spilled material.
2. Place sweepings in an appropriate chemical waste container.
3. Generously cover the contaminated areas with a common household
detergent (e.g. Tide). Using a stiff brush and small amounts of
water, work the detergent into the spill material forming a
slurry. Do not splatter on one's self or bystanders, and
completely avoid skin and eye contact with this material. Brush
the slurry into cracks and crevices and allow to stand for 2-3
4. Again spread absorbents on the slurried liquid and shovel the
absorbed material into the container.
5. Repeat if necessary.
6. Flush the area with water while observing proper environmental
7. Seal container and dispose of in approved pesticide landfill or
Large spills must be handled according to a predetermined plan.
For assistance in developing a plan, contact the Agricultural Chemical
Division, Stauffer Chemical Company, Westport, CT 06880 (29i).
X. LITERATURE CITED
26. The Pesticide Manual: A World Compendium, 6th ed. 1979. C. R.
Worthing, ed. The British Crop Protection Council, Croydon,
England. 655 pp.
29g. Stauffer Chemical Company. 1982. Specimen label: Vapam soil
fumigation solution for all crops. Westport, CT.
29i. Stauffer Chemical Company, Agricultural Chemical Division. 1980.
Product safety information: Vapam Soil Fumigant Solution.
48. Harding, W.C. 1979-80. Pesticide profiles, part two: fungicides
and nematicides. Univ. Maryland, Coop. Ext. Service Bull.
283, 22 pp.
56. Farm Chemicals Handbook, 70th ed. 1984. R. T. Meister, G. L.
Berg, C. Sine, S. Meister, and J. Poplyk, eds. Meister
Publishing Co., Willoughby, OH.