Thiabendazole (Arbotect, Mertect) - Chemical Profile 2/85
CHEMICAL name: 2-(4'-Thiazolyl)-benzimidazole (56)
TRADE name(S): Arbotect, Mertect, TBZ, Tecto, Thibenzole, Apl-
FORMULATION(S): Wettable powder 60%, 45% flowable, smoke generator
TYPE: Benzimidazole fungicide
BASIC PRODUCER(S): Merck and Co., Inc.
MSD Agvet Div.
P.O. Box 2000
123 E. Lincoln Ave.
Rahway, NJ 07065
STATUS: General use
PRINCIPAL USES: Preventative and eradicant chemical against molds,
rots and others on vegetables, turf and ornamentals. Some systemic
action. Used orally on humans and livestock for roundworm control
Fungicide to control green mold, blue mold, and stem end rot of
citrus fruits; to control Cercospora leaf spot on sugar beets; to
control Fusarium basal rot and Penicillium blue mold on ornamental
bulbs and corms; to control brown rot on bananas; to control blue mold
rot, bull's eye rot and gray mold on apples and pears; to control
black rot, scurf and foot rot of sweet potatoes; to control Fusarium
(dry rot) in potato storage. Also as a preservative for reconstituted
tobacco. On soybeans to reduce the severity of pod and stem blight,
anthracnose, brown spot, frog eye leaf spot, and purple seed stain.
Antihelmintic to treat cattle against roundworm infestations, sheep and
goats for roundworm infestations, swine for prevention of infestation
by large roundworms (Ascaris) (56).
Pathogenic fungi controlled include species of Aspergillus,
Botrytis, Ceratocystis, Cercospora, Colletotrichum, Diaporthe,
Fusarium, Giberella, Gloesporium, Oospora, Penicillium, Phoma,
Rhizoctonia, Sclerotinia, Septoria, and Verticillium (26).
It has been demonstrated that considerable thiabendazole persists
in the plant for 2-3 weeks after absorption (51a).
II. PHYSICAL PROPERTIES
MOLECULAR FORMULA: C10 H7 N3 S (26)
MOLECULAR WEIGHT: 201.2 (26)
PHYSICAL STATE: Colorless powder (pure compuond) (26)
MELTING POINT: 304-305 C (pure compound) (26)
VAPOR PRESSURE: Nonvolatile at room temperature but sublimes when
heated strongly to 310 C (pure compound) (26)
SOLUBILITY: c. 10 g/l water at pH 2, 25 C; <50 mg/l water at pH
5-12, 25 C; >50 mg/l water at pH 12, 25 C (pure
III. HEALTH HAZARD INFORMATION
OSHA STANDARD: NA
NIOSH RECOMMENDED LIMIT: NA
ACGIH RECOMMENDED LIMIT: NA
A. ACUTE TOXICITY
ORAL: LD50 = 3300 mg ai/kg (rat); 3850 mg/kg ai/kg
EYES: Irritation studies by application to rabbit's eye
revealed only a slight erythema of a short duration
when thiabendazol was applied as a dry powder (51a).
B. SUBACUTE AND CHRONIC TOXICITY:
No observable clinical effect followed chronic inhalation at 70
mg/m3. In 2-year feeding trials rats receving 40 mg/kg daily showed no
evidence of ill-effect (26).
No evidence of teratogenesis was obtained in a study with rats.
Subacute inhalation studies demonstrated that thiabendazole has a very
low order of subacute toxicity (51a).
IV. ENVIRONMENTAL CONSIDERATIONS
Nonhazardous to wildlife. Nonphytotoxic when used as directed
In mammals, thiabendazole metabolites have been found to be
5-hydroxy-thiabendazole and its glucuronide and sulfate conjugates
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
To be developed.
VI. FIRE AND EXPLOSION INFORMATION
To be developed.
Incompatible with a number of other pesticides, especially copper
compounds and those alkaline in reaction (48).
VIII. PROTECTIVE MEASURES
To be developed.
IX. PROCEDURES FOR SPILLS AND LEAKS
IN CASE OF EMERGENCY, CALL, DAY OR NIGHT
PESTICIDE TEAM SAFETY NETWORK/CHEMTREC
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.
48. Harding, W.C. 1979-80. Pesticide profiles, part two: fungicides
and nematicides. Univ. Maryland, Coop. Ext. Service Bull.
283, 22 pp.
51a. Merck, Sharp and Dohme, Canada Ltd. 1970. Summary data sheet
1970-73 for thiabendazole, a new experimental fungicide.
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.
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