| Chemical Abstract Number (CAS #) |
119904
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| Synonyms | 3,3'-Dimethoxybenzidine |
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(1,1'-Biphenyl)-4,4'-diamine, 3,3'-dimethoxy |
| Analytical Method |
EPA Method 553 |
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| Molecular Formula | C14H16N2O2 |
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| Use | CHEMICAL INTERMEDIATE IN PRODN OF O-DIANISIDINE DIISOCYANATE ;
FOR DETECTION OF PRESENCE OF THIOCYANATES, NITRITES & A NUMBER OF
METALS.
USED IN DYEING LEATHER, PAPER, PLASTIC, RUBBER, TEXTILES
CHEM INT FOR PIGMENTS, EG, PIGMENT ORANGE 16; DYE FOR ACETATE RAYON
(FORMER USE)
Azo dye intermediate
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| Consumption Patterns | ESSENTIALLY 100% AS A CHEM INT FOR DYES AND PIGMENTS
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| Apparent Color | LEAFLETS OR NEEDLES FROM WATER; COLORLESS CRYSTALS WHICH
TURN VIOLET ON STANDING
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| Melting Point | 137 DEG C
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| Molecular Weight | 244.29
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| Sensitivity Data | CAN CAUSE SKIN IRRITATION
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| Environmental Impact | 3,3'-Dimethyoxybenzidine may be released to the environment in waste streams resulting
from its use in the production of azo dyes. No information on the fate of 3,3'-dimethoxybenzidine
(DMB) was found; however, its fate may be predicted based on information on the fate of
benzidine and other aromatic amines. If it is released to the soil it may sorb to the soil with the
amount of adsorption dependent on the pH of the soil, adsorption increasing with decreasing pH.
It may also react with natural substances in the soil like cations such as Fe(III), clay minerals, and
aromatic amines are known to form covalent bonds with humic materials. No information on the
biodegradation of DMB was found; however, it may be subject to biodegradation as benzidine
was 79% degraded in 4 weeks in silty clay loam. If released to water it may readily degrade due to
reaction with hydroxyl radicals, redox reactions with naturally occurring cations, and perhaps
photodegradation. As such, degradation should occur more rapidly in humic waters because of
the presence of reactive radicals, cations and molecules and the fact that aromatic amines are
known to form covalent bonds with humic materials. Its adsorption to sediments will be pH
dependent, with adsorption increasing as pH decreases due to the increase in the amount of
ionized cation species present. It will not bioconcentrate in aquatic organisms or hydrolyze. No
information on the biodegradation of DMB in natural waters was found; limited data from
laboratory screening tests suggest that it may be susceptible to biodegradation. Since it absorbs
light above 290 nm, it may be susceptible to direct photolysis near the surface of natural waters. If
released to the atmosphere, it may be subject to direct photolysis due to its absorption of light
greater than 290 nm. 3,3'-Dimethoxybenzidine should exist almost entirely in the particulate phase
in the ambient atmosphere; the estimated vapor phase half-life in the atmosphere is 2 hrs as a
result of reaction with photochemically produced hydroxyl radicals. Human exposure to
3,3'-dimethoxybenzidine will occur through occupational contact during its manufacture and use
as an intermediate in the manufacture of dyes.
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| Environmental Fate | TERRESTRIAL FATE: No information on the fate of 3,3'-dimethoxybenzidine (DMB)
in soil were found; however, its behavior may be similar to the structurally very similar benzidine.
Therefore, if DMB is released to soil it may sorb to the soil. The adsorption may be dependent
upon the pH, with adsorption increasing with decreasing pH due to the increase in the amount of
cationic ionized species. It may react with natural cations such as Fe(III) in the soil and also with
clay minerals. Aromatic amines are known to form covalent bonds with humic materials, adding to
quinone-like structures followed by a slow oxidation. No information on the biodegradation of
DMB in soil was found; however, it may be subject to biodegradation as benzidine was 79%
degraded in 4 weeks in silty clay loam(1,SRC).
AQUATIC FATE: No information on the fate of 3,3'-dimethoxybenzidine (DMB) in water was
located. However, by analogy to benzidine, it may readily degrade due to reaction with radicals,
redox reactions with naturally occurring cations, and perhaps photodegradation. Such degradation
should occur more rapidly in humic waters because of the presence of reactive radicals, cations
and molecules, and the fact that aromatic amines are known to form covalent bonds with humic
materials, quinone-like structures followed by a slow oxidation. Its adsorption to sediments will
be pH dependent, with adsorption increasing as pH decreases due to the increase in the amount of
ionized cation species present. It will not bioconcentrate in aquatic organisms, volatilize from
water, or hydrolyze in water. No information on the biodegradation of DMB in natural waters
was found; limited data from laboratory screening tests suggests that it may be susceptible to
biodegradation. Since it absorbs light above 290 nm, it may be susceptible to direct photolysis.
ATMOSPHERIC FATE: Based on an experimental water solubility value of 60 mg/L at 25 deg
C , a vapor pressure for 3,3'-dimethoxybenzidine can be estimated to be 8.8X10-9 mm Hg at 25
deg C. This vapor pressure value suggests that 3,3'-dimethoxybenzidine will exist almost
entirely in the particulate phase in the ambient atmosphere . Vapor phase
3,3'dimethoxybenzidine is expected to degrade relatively rapidly in an average ambient
atmosphere (estimated half-life of about 2 hrs) by reaction with photochemically produced
hydroxyl radicals . It may be subject to direct photolysis in the atmosphere due to its absorption
of light >290 nm(5,SRC).
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