| Chemical Abstract Number (CAS #) |
119937
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| Synonyms | o-Tolidine |
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3,3'-Dimethylbenzidine | [1,1'-Biphenyl]-4,4'-diamine, 3,3'-dimethyl- |
| Analytical Method |
EPA Method 553 |
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| Molecular Formula | C14H16N2 |
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| Use | VERY SENSITIVE REAGENT FOR DETECTION OF GOLD (1:10 MILLION
DETECTABLE); AND FREE CHLORINE IN WATER
CHEM INT FOR AZO DYES AND 3,3'-DIMETHYL-4,4'-BIPHENYLENE
DIISOCYANATE
Curing agent for urethane resins.
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| Consumption Patterns | Over 75% of DMB is used as a dye & as an intermed in the production of dyestuffs &
pigments approximately 20% of DMB is used in the production of polyurethane-based
high-strength elastomers, coatings, & rigid plastics.
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| Apparent Color | WHITE TO REDDISH CRYSTALS OR CRYSTAL POWDER
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| Boiling Point | 300 DEG C
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| Melting Point | 129-131 DEG C
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| Molecular Weight | 212.28
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| Sensitivity Data | Skin and eye irritant.
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| Environmental Impact | 3,3'-Dimethylbenzidine is used in dyes, as a reagent for gold and for free chlorine in
water, and as a curing agent for urethane resins. 3,3'-Dimethylbenzidine released to soil will have
a moderate tendency to sorb to organic matter But is expected to covalently bond to humic
material like other aromatic amines. Thus leaching should not be rapid in soils. Based upon
screening studies biodegradation may be an important degradative process while hydrolysis will
not be important. No information was found about volatilization. In water, 3,3'-dimethylbenzidine
will have a low tendency to sorb but should covalently bond to sediments. Bioconcentration in
aquatic organisms should not be important, because of its low octanol/water partition coefficient.
Biodegradation will probably be significant based on screening studies, while hydrolysis will not.
No information was found on photolysis or evaporation. An estimated half-life for vapor phase
3,3'-dimethylbenzidine in the atmosphere is 4.0 hours based upon reaction with photochemically
generated hydroxyl radicals. Human exposure to 3,3'-dimethylbenzidine may occur from its use in
dyes, reagents, and curing agents for urethane resins.
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| Environmental Fate | TERRESTRIAL FATE: 3,3'-Dimethylbenzidine released to soil will have a moderate
tendency to sorb to organic matter (estimated Koc is 447) but should covalently bond to humic
material in soil. Thus leaching should not be rapid in soils. Biodegradation may be the most
important degradative mechanism for 3,3'-dimethylbenzidine in soil based on screening studies .
Hydrolysis will probably not be important. No information was found about volatilization from
soil surfaces.
AQUATIC FATE: 3,3'-Dimethylbenzidine released to water will have a low tendency to
bioconcentrate in aquatic organisms (log Kow is 2.34 and estimated BCF is 35) but should
covalently bond to humic material in sediment. Biodegradation is probably an important removal
process for 3,3'-dimethylbenzidine in water while hydrolysis is not. No information was found on
photolysis or evaporation.
ATMOSPHERIC FATE: An estimated half-life for 3,3'-dimethylbenzidine in the vapor phase of
the atmosphere is 4.0 hours due to reaction with photochemically-produced hydroxyl radicals.
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