Description
Nabam is a toxic fungicide, considered to be a carcinogen and there are some concerns that it may be an endocrine disrupter. It is very soluble in water, hydrolyzes rapidly, rapidly degrades in soil and so leaching to groundwater is unlikely. Its ETU metabolite is an environmental concern. Highly toxic to aquatic organisms. It is not toxic to honeybees. Toxicity data for other species has not been found.
Chemical Properties
Colorless crystals when pure. Easily sol-uble in water.
Chemical Properties
Colorless crystalline solid (when pure). Light
amber crystalline solid or 22% wettable powder solution.
Slight odor of sulfide.
Uses
Plant fungicide, starting material for derivativesthat are also pesticides.
Uses
Nabam provides protection against fungal diseases of cotton,
capsicums and onions when applied to soil.
Definition
ChEBI: A dithiocarbamate salt that is the disodium salt of ethylenebis(dithiocarbamic acid). A fungicide, algicide and bactericide used on various crops including on cotton, capsicums, onions and rice crops, it is considered to be a carcinogen, so is not licensed
for use within the European Union. Mixing nabam with zinc sulfate affords the fungicide zineb.
Production Methods
Nabam is produced through a straightforward aqueous-phase synthesis involving the reaction of ethylenediamine, carbon disulfide and sodium hydroxide. In this process, ethylenediamine is first dissolved in water and treated with carbon disulfide under controlled temperature and stirring, forming a dithiocarbamate intermediate. Sodium hydroxide is then added to neutralise the reaction and convert the intermediate into its disodium salt form, yielding nabam.
General Description
Colorless to light amber solid with a a slight odor. Mixes with water.
Air & Water Reactions
Water soluble. Decomposes in boiling hot to give poisonous hydrogen sulfide and flammable carbon disulfide.
Reactivity Profile
NABAM is a dithiocarbamate. Flammable gases are generated by the combination of thiocarbamates and dithiocarbamates with aldehydes, nitrides, and hydrides. Thiocarbamates and dithiocarbamates are incompatible with acids, peroxides, and acid halides.
Hazard
Irritant to skin and mucous membranes, nar-cotic in high concentrations, use may be restricted.
Health Hazard
Contact with liquid irritates eyes and may cause mild to severe erythema of skin as well as sensitization reactions.
Fire Hazard
Behavior in Fire: If water solution boils, poisonous hydrogen sulfide and highly flammable carbon disulfide vapors form.
Agricultural Uses
Fungicide, Algaecide, Herbicide, Microbiocide: Nabam is a broad-spectrum fungicide/bactericide/
algaecide used to prevent crop damage by fungi, to protect
harvested products from deterioration, and as an industrial
microbiocide. As a result of the U.S. EPA review of nabam
in 1989, all food uses were voluntarily canceled by
the manufacturers except for one FDA-regulated food use
on sugar mill grinding, crusher and/or diffuser systems,
e.g., processing water systems. Registered only for nonfood
application. Not approved for use in EU countries.
Registered for use in the U.S. and Canada.
Trade name
AMA-30®, Kemira Chemical (Finland);
CAMBELL’S® NABAM SOIL FUNGICIDE; CARBON
D®; NALCO D-62C44®; CHEM-BAM®; DITHANE
A-40®; DITHANE A-46®; DITHANE D-14®[C];
NAFUN-IPO®; NALCO® D-62C44; PARZATE®;
SPRING-BAK®
Mechanism of action
Non-specific, exact mode of action is unclear but thought to inhibit protein development.
Safety Profile
intraperitoneal route.
Experimental teratogenic and reproductive
effects. Mutation data reported. When
heated to decomposition it emits very toxic
fumes of NOx, Na2O, and SOx. See also
CARBAMATES.
Potential Exposure
Nabam is a broad spectrum dithiocarbamate
fungicide/bactericide/algaecide/herbicide/microbiocide
used to prevent crop damage by fungi, to protect
harvested products from deterioration, and as an industrial
microbiocide. As a result of the United States
Environmental Protection Agency review of nabam in
1989, all food uses were voluntarily canceled by the manufacturers
except for one FDA-regulated food use on sugar
mill grinding, crusher, and/or diffuser systems, e.g., processing
water systems. All other uses of nabam are for the
control of algae, slime-forming bacteria, and fungi in
indoor nonfood environments, paper mills, water cooling
systems, drilling mud and packer fluids, and secondary oil
recovery water system. Registered in the United States only
for nonfood application.
Metabolic pathway
Nabam and other alkylenebis(dithi0carbamate) fungicides are degraded
and metabolised via a common pathway. Limited information is available
to describe the fate of nabam in soil and animals. Based on information
generated with structurally similar compounds (see maneb, zineb), the
initial degradation reaction of nabam in water and plants involves the
dissociation of the metal complex and decomposition to numerous degradation
products including ethylenethiourea (ETU) and ethyleneurea (EU)
as major products (Scheme 1).
Shipping
UN3077 Environmentally hazardous substances,
solid, n.o.s., Hazard Class: 9; Labels: 9-Miscellaneous hazardous
material, Technical Name Required.
Purification Methods
It crystallises (as hexahydrate) from aqueous ethanol. It is a skin irritant. [Beilstein 4 III 149, 4 IV 234.]
Degradation
In aqueous solution, ethylenebis( thiocarbamate) compounds (eg. maneb,
zineb) decompose to yield ethylenetl.uourea (ETU, 2) and 5,6-dihydro-
3H-imidazo[2,l-c]-1,2,4-dithiazole-3-thione(3) (kaars Sijpestijn and Vonk,
1974). Nabam (1) decomposed to a complex pattern of degradation
products when exposed to aqueous solution at 90 °C (Marshall, 1977). A
possible degradation pathway involves the oxidation of nabam to
ethylenethiuram disulfide (4) which is further degraded to ETU (2) and
compound 3. Other decomposition products included carbon disulfide,
hydrogen sulfide, ethylene diisothiocyanate (5), β-aminoethy 1 isothiocyanate
(6), β-aminoethyl dithiocarbamate (7) and ethylenediamine (8).
The primary hydrolytic and thermal degradation pathways of nabam are
presented in Scheme 1
ETU in aqueous solution was ultimately converted into 2-imidazoline
(9) and EU (10) (kaars Sijpesteijn and Vonk, 1974).
Incompatibilities
Combustible material. Dust may form
explosive mixture in air, water, acid, oxidizing materials.
Heat or contact with moisture or acids causes rapid decomposition
and the generation of toxic and flammable hydrogen
sulfide and carbon disulfide. Dithiocarbamate esters
are combustible. They react violently with powerful oxidizers
such as calcium hypochlorite. Poisonous gases are generated
by the thermal decomposition of dithiocarbamate
compounds, including carbon disulfide, oxides of sulfur,
oxides of nitrogen, hydrogen sulfide, ammonia, and methylamine.
Thio and dithiocarbamates slowly decompose in
aqueous solution to form carbon disulfide and methylamine
or other amines. Such decompositions are accelerated by
acids. Flammable gases are generated by the combination
of dithiocarbamate with aldehydes, nitrides, and hydrides.
Dithiocarbamate are incompatible with acids, peroxides,
and acid halides. Corrosive to iron, copper, brass, and zinc
metals, especially in the presence of moisture. Heat alkalies
(lime), moisture can cause decomposition. Decomposes
on prolonged storage; by moisture, light, and heat.
Degradation produces ethylene thiourea.
Toxics Screening Level
The initial threshold screening level (ITSL) for NABAM is 1 μg/m3 based on an annual averaging time.
Waste Disposal
Do not discharge into drains
or sewers. Dispose of waste material as hazardous waste
using a licensed disposal contractor to an approved landfill.
Consult with environmental regulatory agencies for guidance
on acceptable disposal practices. Generators of waste
containing this contaminant (≥100 kg/mo) must conform
with EPA regulations governing storage, transportation,
treatment, and waste disposal. A potential candidate for liquid
injection incineration at a temperature range of
650 1600℃ and a residence time 0.1-2 seconds. Also, a
potential candidate for rotary kiln incineration at a temperature
range of 820 1600℃ and residence times of seconds
for liquids and gases, and hours for solids.
