Congo red

696.66

696.083740

3894858

209-358-4

3U05FHG59S

DTXSID4022816

C81102

BROWNISH-RED POWDER; IN WATER YELLOWISH-RED & IN ETHANOL ORANGE

29215900

233

10.78740

Red Brown Powder/Solid

0.995 g/mL at25 °C

>360 °C

H2O: soluble 10mg/mL

Flammables area

<1 Pa

LD50 i.v. in rats: 190 mg/kg (Richardson, Dillon)

ODORLESS

SOLN HAVE PH OF 8-9.5

Decomposes on exposure to acid fumes.

2811

3

45-63-36

53-45-37/39-26

QK1400000

T,Xi

Stable. Incompatible with strong oxidizing agents.

P201-P280-P308 + P313

H350-H361d

SRP: At the time of review, criteria for land treatment or burial (sanitary landfill) disposal practices are subject to significant revision. Prior to implementing land disposal of waste residue (including waste sludge), consult with environmental regulatory agencies for guidance on acceptable disposal practices.

|Danger|H350: May cause cancer [Danger Carcinogenicity]|P201, P202, P281, P308+P313, P405, and P501|H319 (25.32%): Causes serious eye irritation [Warning Serious eye damage/eye irritation]|P201, P202, P264, P280, P281, P305+P351+P338, P308+P313, P337+P313, P405, and P501|Aggregated GHS information provided by 154 companies from 7 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.|Warning|H319: Causes serious eye irritation [Warning Serious eye damage/eye irritation]

beta-Amyloid peptides are neurotoxic when applied to primary cultures of hippocampal neurons from the embryonic rat. This neurotoxic effect can be inhibited completely by certain dyes. ... The most potent of these are Congo Red and Congo Rubin. ... Congo red also inhibits the neurotoxic effects of the human pancreatic amylodiogenic peptide amylin. It is postulated that these dyes, by interacting with the beta-pleated sheet structure of amylodiogenic peptides, prevent aggregation and hence neurotoxicity.|beta-Amyloid (beta A) is normally produced as a nontoxic soluble peptide. In Alzheimer disease, beta A aggregates and accumulates in the brain as inert diffuse plaques or compact plaques associated with neurodegenerative changes. To determine the relationship of neurotoxicity to the physical state of beta A ... creation of (1) nonamyloidogenic amorphous aggregates of beta A (amorphous beta A, Am-beta A) analogous to diffuse plaques and (2) amyloidogenic fibrils of beta A (fibrillar beta A, Fib-beta A) analogous to compact plaques. In primary rat hippocampal culture, Fib-beta A was neurotoxic, where as Am-beta A was not toxic. Fib-beta A caused significant loss of synapses in viable neurons, while Am beta-A had no effect on synapse number. The amyloid fibril binding dye Congo red inhibited Fib-beta A neurotoxicity by inhibiting fibril formation or by binding to preformed fibrils. Congo red also inhibited the pancreatic islet cell toxicity of diabetes associated amylin, another type of amyloid fibril. These results indicate that beta A neurotoxicity requires fibril formation.

C.I. Direct Red 28's production and use as an indicator dye, biological stain, diagnostic aid in medicine(1), as a fabric and paper dye(2), and a gelling agent for poly(vinyl alcohol)(3) may result in its release to the environment through various waste streams(SRC).

TERRESTRIAL FATE: Based on a recommended classification scheme(1), an estimated Koc value of 7(SRC), determined from a measured water solubility(2) and a recommended regression-derived equation(3), indicates that C.I. Direct Red 28 will have very high mobility in soil(SRC). However, C.I. Direct Red 28 was adsorbed by sediment with increasing adsorption seen with increasing pH; no adsorption was shown below pH 4(4). This was thought to occur via cation exchange processes due to weakly basic amino and strongly acidic sulfonate groups(4). This process(4) may slow down or prevent leaching(SRC). As C.I. Direct Red 28 is an ionic compound, volatilization of this compound will not be important from moist soil surfaces(5,SRC). Based on limited data, C.I. Direct Red 28 is expected to be resistant to aerobic biodegradation in soil(SRC); C.I. Direct Red 28 was not biodegraded in a standard 5 day BOD test using a sewage inoculum(6). However, under anaerobic conditions, this dye is expected to rapidly biodegrade(SRC), forming benzidine as a metabolic product(7).|AQUATIC FATE: Based on a recommended classification scheme(1), an estimated Koc value of 7(SRC), determined from a measured water solubility(2) and a recommended regression-derived equation(1), indicates that C.I. Direct Red 28 should not adsorb to suspended solids and sediment in water(SRC). However, due to the ionic nature of C.I. Direct Red 28, the retention of the dye by ion-exchange processes at pH values greater than 4(3) may lead to increased adsorption on some sediment and particulate surfaces(SRC). As C.I. Direct Red 28 is an ionic compound, volatilization from water surfaces is not expected(3,SRC). According to a classification scheme(4), an estimated BCF value of 1(1,SRC), from a measured water solubility(2), suggests that bioconcentration in aquatic organisms is low(SRC). Based on limited data, C.I. Direct Red 28 is expected to be resistant to aerobic biodegradation in water(SRC); C.I. Direct Red 28 was not biodegraded in a standard 5 day BOD test using a sewage inoculum(5). However, under anaerobic conditions, this dye is expected to rapidly biodegrade(SRC). A half-life of 3.6 days was measured for C.I. Direct Red 28 in an anaerobic pond sediment-water system(3); loss was due to biodegradation.|ATMOSPHERIC FATE: The ionic state of C.I. Direct Red 28 makes this compound essentially non-volatile(1,SRC), therefore this compound should exist in the particulate phase in the ambient atmosphere. Particulate-phase C.I. Direct Red 28 may be physically removed from the air by wet and dry deposition(SRC).

An estimated BCF value of 1 was calculated for C.I. Direct Red 28(SRC), using a measured water solubility of 1.16X10+5(1) and a recommended regression-derived equation(2). According to a classification scheme(3), this BCF value suggests that bioconcentration in aquatic organisms is low(SRC).

The Koc of C.I. Direct Red 28 is estimated as approximately 7(SRC), using a measured water solubility of 1.16X10+5(1) and a regression-derived equation(2,SRC). According to a recommended classification scheme(3), this estimated Koc value suggests that C.I. Direct Red 28 has very high mobility in soil(SRC). Due to the ionic nature of the dye, the retention of C.I. Direct Red 28 by ion-exchange processes(4,SRC) may slow down or prevent leaching(SRC). C.I. Direct Red 28 was adsorbed by sediment (cation exchange capacity= 3.72 meq/100 mg; 1.2% organic carbon) with increasing adsorption seen with increasing pH up to pH 8 to 9. No adsorption was shown below pH 4(5). This was thought to occur via cation exchange processes due to weakly basic amino and strongly acidic sulfonate groups(5). Adsorption to sediment was also affected by the addition of inorganic salts such as calcium or sodium chloride at concentrations of 0.001 to 0.01 M; the addition of either salt enhanced the sorption of C.I. Direct Red 28(5).

Since C.I. Direct Red 28 is an ionic compound, volatilization from water and moist soil surfaces will not be important(1,SRC).

NIOSH (NOES Survey 1981-1983) has statistically estimated that 4273 workers (3443 of these are female) are potentially exposed to C.I. Direct Red 28 in the US(1). Occupational exposure may be through inhalation of dust and dermal contact with this compound at workplaces where C.I. Direct Red 28 is produced or used(SRC). The general population will be exposed to C.I. Direct Red 28 via dermal contact with products containing this compound.

Dyes|/SRP: FORMER USE/: AS MUCH AS 80% OF INJECTED DOSE CAN BE RETAINED BY ABNORMAL AMYLOID DEPOSIT. THUS, DYE WILL DISAPPEAR MORE RAPIDLY FROM BLOOD OF AFFECTED PT THAN IT DOES FROM NORMAL INDIVIDUAL. IN AMYLOID GROWTHS IN LIVER, NO DYE...IN URINE; IN AMYLOID GROWTHS IN KIDNEYS, SUBSTANTIAL AMT APPEAR IN URINE.|MEDICATION (VET): HEMOSTATIC AGENT|Test for amyloidosis and for achlorhydria. ... Use of Congo Red ... as pharmaceutical colorant is not permitted by the FDA or the European Economic Community.

Anaphylactic shock, substernal pain, cold sweat, visual impairment, vomiting. Fatal after intravenous use.

Chemicals and substances that impart color including soluble dyes and insoluble pigments. They are used in INKS; PAINTS; and as INDICATORS AND REAGENTS. (See all compounds classified as Coloring Agents.)

Congo red, an azo dye derived from benzidine, and 2-azoxyfluorene, a derivative of 2-aminofluorene, were reduced during overnight incubation with a suspension of rat intestinal bacteria. HPLC and uv spectral analysis verified the presence of benzidine in the extracts of the Congo red incubations. ... Extracts of the Congo red incubations were mutagenic toward Salmonella typhimurium TA1538 in the presence of post-mitochondrial activating system, but Congo red was not mutagenic without this reductive pretreatment. ... The utility of the Ames test in screening for potential mutagens may be expanded by a reductive pretreatment utilizing cecal bacteria.

MAY HAVE SEVERE ALLERGIC REACTION (ANAPHYLACTIC SHOCK). POSSIBLE CARCINOGEN.|ADDN OF EVANS BLUE & CONGO RED TO HUMAN PLATELET-RICH PLASMA CAUSED PLATELET AGGREGATION. IV ADMINISTRATION OF CONGO RED WAS HAZARDOUS, PARTICULARLY IN HYPOALBUMINETIC PATIENTS.

Congo Red

VET: FORMERLY MARKETED AS 1% SOLN- NOW STANDARDIZED AS 0.6% SOLN.

1-Naphthalenesulfonic acid, 3,3'-[[1,1'-biphenyl]-4,4'-diylbis(2,1-diazenediyl)]bis[4-amino-, sodium salt (1:2): ACTIVE|S - indicates a substance that is identified in a final Significant New Use Rule.|SOL DYE TAKEN UP DIRECTLY BY FIBERS, PRESUMABLY DUE TO SELECTIVE ADSORPTION. USUALLY APPLIED TO COTTON OR...(COTTON-WOOL MIXT). DYEING ASSISTANTS...SODIUM CHLORIDE OR SODIUM SULFATE ARE USED TO OBTAIN HIGHER CONCN OF DYE ON FIBERS. /DIRECT DYE/