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Publication #PI-62

Pesticide Toxicity Profile: Thiocarbamate Fungicides1

Frederick M. Fishel2

This document provides a general overview of human toxicity, a listing of laboratory animal and wildlife toxicities, and a cross-reference of chemical, common, and trade names of thiocarbamate pesticides that can be used as fungicides and that are registered for use in Florida.

General

As a chemical family, the thiocarbamates are a group of pesticides with a wide range of uses. Some are used as fungicides, while others have herbicidal activity. Thiocarbamate fungicides are applied for a wide variety of uses including protection of seeds, seedlings, ornamentals, turfgrass, vegetables, and fruit. They have been known as the “old reliables” because they have been in use since the 1930s and 40s. Unlike the carbamate insecticides (UF/IFAS EDIS Document PI-51 [http://edis.ifas.ufl.edu/PI088]), the thiocarbamate fungicides have very few insecticidal properties. Members of this chemical family include ferbam, metam-sodium, thiram, and ziram. Ferbam and ziram are used widely on fruit and nut trees, vegetables and tobacco. Thiram is used as a seed protectant and for certain fungus diseases of peaches, strawberries, and tomatoes. As a turfgrass fungicide, it is applied for control of brown patch and dollar spot. It also has animal repellant properties to protect fruit trees and ornamentals from damage by rabbits, rodents, and deer. Metam-sodium is classified as a restricted-use pesticide and used in agricultural crop production. It is applied as a soil biocide and fumigant to kill fungi, bacteria, weed seeds, nematodes, and insects. Homeowner uses of metam-sodium in the United States have been cancelled. One of its trade products has a Federal restricted-use classification for the control of tree roots in sewage and waste water systems. Product formulations of the thiocarbamate fungicides include aqueous solutions, wettable powders, dusts, flowables, water dispersible granules, emulsifiable concentrates, and granules.

Toxicity

Dust from ferbam and ziram is irritating to the skin, respiratory tract, and eyes. Prolonged inhalation of ziram is reported to have caused neural and visual disturbances. Thiram is a common component of latex and possibly responsible for some of the allergies attributed to latex. Contact dermatitis has occurred in occupationally exposed workers. Systemic human poisonings by thiram itself have been rare, probably due to limited absorption. Metam-sodium can be very irritating to the skin, like most fumigants in general. Because of its extreme irritation of the lungs, it must be used in outdoor settings, and stringent precautions must be taken to avoid inhalation of evolved gas. Mammalian toxicities for the thiocarbamate fungicides are shown in Table 1. Table 2 lists the toxicities to wildlife by the common name of the pesticide. Table 3 provides a cross listing of many of the trade names under which these products are registered and sold in Florida.

Additional Information

Tables

Table 1. 

Thiocarbamate fungicide mammalian toxicities (mg/kg of body weight).

Common name

Rat oral LD50

Rabbit dermal LD50

Ferbam

>17,000

---

Metam-sodium

1,891

>3,074

Thiram

1,000

>5,000

Ziram

1,400

>6,000

Table 2. 

Thiocarbamate fungicide wildlife toxicity ranges.

Common name

Bird acute oral LD50 (mg/kg)*

Fish (ppm)**

Bee

Ferbam

---

MT

PNT

Metam-sodium

MT

HT

PNT

Thiram

ST

HT

PNT

Ziram

---

MT

PNT

*Bird LD50: Practically nontoxic (PNT) = >2,000; slightly toxic (ST) = 501 – 2,000; moderately toxic (MT) = 51 – 500; highly toxic (HT) = 10 – 50; very highly toxic (VHT) = <10.

**Fish LC50: PNT = >100; ST = 10 – 100; MT = 1 – 10; HT = 0.1 – 1; VHT = <0.1.

Bee: HT = highly toxic (applied product and residues kill on contact); MT = moderately toxic (kills if applied over bees); PNT = relatively nontoxic (relatively few precautions necessary).

Table 3. 

Cross reference list of common, trade and chemical names of thiocarbamate fungicides.

Common name

Trade names*

Chemical name

Ferbam

Ferbam®

Ferric dimethyldithiocarbamate

Metam-sodium

Metam®, Vapam®

Sodium N-methyldithiocarbamate

Thiram

Aules®, Thiram®

Bis(dimethylthiocarbamoyl) disulfide

Ziram

Ziram®, Vancide®

Zinc bis(dimethyldithiocarbamate)

*Does not include manufacturers prepackaged mixtures.

Footnotes

1.

This document is PI-62, one of a series of the Agronomy Department, UF/IFAS Extension. Original publication date September 2005. Revised March 2014. Reviewed March 2014. Visit the EDIS website at http://edis.ifas.ufl.edu.

2.

Frederick M. Fishel, professor, Agronomy Department, and director, Pesticide Information Office; UF/IFAS Extension, Gainesville, FL 32611.

The use of trade names in this publication is solely for the purpose of providing specific information. UF/IFAS does not guarantee or warranty the products named, and references to them in this publication do not signify our approval to the exclusion of other products of suitable composition. Use pesticides safely. Read and follow directions on the manufacturer's label.


The Institute of Food and Agricultural Sciences (IFAS) is an Equal Opportunity Institution authorized to provide research, educational information and other services only to individuals and institutions that function with non-discrimination with respect to race, creed, color, religion, age, disability, sex, sexual orientation, marital status, national origin, political opinions or affiliations. For more information on obtaining other UF/IFAS Extension publications, contact your county's UF/IFAS Extension office.

U.S. Department of Agriculture, UF/IFAS Extension Service, University of Florida, IFAS, Florida A & M University Cooperative Extension Program, and Boards of County Commissioners Cooperating. Nick T. Place, dean for UF/IFAS Extension.