3,30-Dichlorobenzidine is a gray or purplecrystalline solid. Molecular weight =253.14; Boilingpoint =368℃; Freezing/Melting point = 132.8℃;Autoignition temperature =350℃. Hazard Identification(based on NFPA-704 M Rating System): Health 0,Flammability 1, Reactivity 0. Practically insoluble in water;solubility = 0.07% at 15℃.
3,3’-Dichlorobenzidine is a gray or purple
crystalline solid.
colourless to white crystalline solid
Colorless to grayish-purple needles or crystals with a mild or pungent odor
Intermediate in the manufacture of azo dyes and pigments for printing inks, textiles, paints,
plastics, and crayons; curing agent for isocyanate-terminated polymers and resins; rubber
compounding ingredient; analytical determination of gold; formerly used as chemical intermediate
for direct red 61 dye.
Used in the production of yellow and
red pigments for the printing ink, textile, paper,
paint, rubber, plastic, and related industries
ChEBI: 3,3'-Dichlorobenzidine is an organochlorine compound, a member of biphenyls and a member of monochlorobenzenes.
Gray to purple crystalline powder. Insoluble in water. Very toxic. Used in the dye industry, curing agent for isocyanate terminated resins.
A halogenated amine. Amines are chemical bases. They neutralize acids to form salts plus water. These acid-base reactions are exothermic. The amount of heat that is evolved per mole of amine in a neutralization is largely independent of the strength of the amine as a base. Amines may be incompatible with isocyanates, halogenated organics, peroxides, phenols (acidic), epoxides, anhydrides, and acid halides. Flammable gaseous hydrogen is generated by amines in combination with strong reducing agents, such as hydrides.
3,3'-Dichlorobenzidine (DCB)
is carcinogenic in several animal species.
Confirmed carcinogen
with experimental carcinogenic and
tumorigenic data. Human mutation data
reported. When heated to decomposition it
emits very toxic fumes of Cl and NOx.
A halide-and amine-substituted aromatic compound used in the dye industry, curing agent for
isocyanate terminated resins. The major uses of dichlorobenzidine are in the manufacture of pigments for printing
ink, textiles, plastics, and crayons and as a curing agent
for solid urethane plastics. There are no substitutes for
many of its uses. Additional groups that may be at risk
include workers in the printing or graphic arts professions
handling the 3,3’-DCB-based azo pigments. 3,3’-DCB may
be present as an impurity in the pigments, and there
is some evidence that 3,3’-DCB may be metabolically
liberated from the azo pigment
If this chemical gets into the eyes, remove anycontact lenses at once and irrigate immediately for at least15 min, occasionally lifting upper and lower lids. Seek medical attention immediately. If this chemical contacts theskin, remove contaminated clothing and wash immediatelywith soap and water. Seek medical attention immediately. Ifthis chemical has been inhaled, remove from exposure,begin rescue breathing (using universal precautions, including resuscitation mask) if breathing has stopped and CPR ifheart action has stopped. Transfer promptly to a medicalfacility. When this chemical has been swallowed, get medical attention. Give large quantities of water and inducevomiting. Do not make an unconscious person vomit.
Studies in several test systems have shown
DCB to be genotoxic in vitro and in vivo and
suggest that this effect most likely mediates the
carcinogenicity of the chemical. In vitro, DCB
has induced sister chromatid exchanges,
unscheduled DNA synthesis, and positive
responses in bacterial Salmonella assays; in vivo
DCB induced micronuclei in polychromatic
erythrocytes in male mice and fetuses.
Because of demonstrated potent carcinogenicity
in multiple animal species, evidence of
genotoxicity, and structural relationship to the
known bladder carcinogen benzidine, DCB
should be regarded as a probable human carcinogen
and exposure by any route should be
avoided.
3,3￠-Dichlorobenzidene has no threshold
limit value (TLV) exposure limit and is classified
as an A3, confirmed animal carcinogen
with unknown relevance to humans, and a
notation for skin absorption.
Synthesized from o-chloronitrobenzene in the presence of NaOH and zinc dust (Shriner et
al., 1978).
Biological. In activated sludge, 2.7% mineralized to carbon dioxide after 5 d (Freitag et al.,
1985). Sikka et al. (1978) reported 3,3′-dichlorobenzidine is resistant to degradation by indigenous
aquatic microbial communities in a 4-wk period. Under aerobic and anaerobic conditions,
3,3′-dichlorobenzidine is mineralized very slowly (Boyd et al., 1984; Chung and Boyd, 1987).
Nyman et al. (1997a) studied the transformation of 3,3′-dichlorobenzidine under laboratory
controlled conditions at 20 °C. Wet sediment (50 g) and water (150 mL) from Lake Macatawa,
Holland, MI were placed in glass serum bottles and purged with nitrogen to ensure anaerobic
conditions to which 3,3′-dichlorobenzidine was added. The bottles were incubated in the dark at
20 °C for 12 months. Soil and water samples were retrieved periodically for transformation
product identification using HPLC. The investigators identified 3-chlorobenzidine as a transient
metabolite from the biological transformation of 3,3′-dichlorobenzidine. 3-Chlorobenzidine
rapidly dechlorinated forming the end product benzidine.
Photolytic. An aqueous solution subjected to UV radiation caused a rapid degradation (half-life
<10 min) to monochlorobenzidine, benzidine, and several unidentified, brightly-colored, waterinsoluble
chromophores (Banerjee et al., 1978). In a similar experiment, 3,3′-dichlorobenzidine in
an aqueous solution was subjected to radiation at λ=310 nm for approximately 15 min. During the
period of irradiation, concentrations of 3,3′-dichlorobenzidine decreased rapidly. 3-Chlorobenzidine
formed as a transient intermediate which underwent dechlorination forming a benzidine,
a stable photoproduct. Depending upon the wavelength used, the benzidine yields ranged from 8
to 12% of the total 3-chlorobenzidine transformed (Nyman et al., 1997). A carbon dioxide yield of
41.2% was achieved when 3,3′-dichlorobenzidine adsorbed on silica gel was irradiated with light
(λ >290 nm) for 17 h (Freitag et al., 1985).
Chemical/Physical. 3,3′-Dichlorobenzidine will not hydrolyze to any reasonable extent (Kollig,
1993).
At influent concentrations of 1.0, 0.1, 0.01, and 0.001 mg/L, the GAC adsorption capacities at
were 300, 190, 120, and 73 mg/g, respectively (Dobbs and Cohen, 1980).
Color Code—Blue: Health Hazard/Poison: Storein a secure poison location. Prior to working with thischemical you should be trained on its proper handling andstorage. Store in tightly closed containers in a cool, wellventilated area. A regulated, marked area should be established where this chemical is handled, used, or stored incompliance with OSHA Standard 1910.1045
UN2811 Toxic solids, organic, n.o.s., Hazard
Class: 6.1; Labels: 6.1-Poisonous materials, Technical
Name Required
Crystallise the benzidine from EtOH, pet ether (m 133o) or *benzene. [Beilstein 13 H 234, 13 I 67, 13 II 106, 13 III 477, 13 IV 384.] CARCINOGEN.
Incompatible with oxidizers (chlorates,
nitrates, peroxides, permanganates, perchlorates, chlorine,
bromine, fluorine, etc.); contact may cause fires or explosions. Keep away from alkaline materials, strong bases,
strong acids, oxoacids, and epoxides. Achemical base: neutralize acids to form salts plus water with an exothermic
reaction. May be incompatible with isocyanates, halogenated
organics, peroxides, phenols (acidic), epoxides, anhydrides,
and acid halides. Flammable gaseous hydrogen is generatedby amines in combination with strong reducing agents such
as hydrides, nitrides, alkali metals, and sulfides.
Incineration (816C,
0.5 second for primary combustion; 1204C, 1.0 second for
secondary combustion). The formation of elemental
chlorine can be prevented through injection of steam ormethane into the combustion process. nitrogen oxides
may be abated through the use of thermal or catalytic
devices. 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
