Chromic acid (H2CrO4)

118.01000

117.93600

231-801-5

SA8VOV0V7Q

1755|1463

DTXSID8034455

Dark purplish-red crystals /Anhydrous chromic acid/|Red ortho crystals /Anhydrous chromic acid, chromic trioxide/|Brown solid

74.60000

-0.59120

Liquid

1.67-2.82 g/cm³

196 °C

330ºC

250ºC

Solubility in water, g/100ml: 61.7 (good)

Storage site should be as close as practical to lab in which carcinogens are to be used, so that only small quantities required for expt need to be carried. Carcinogens should be kept in only one section of cupboard, an explosion-proof refrigerator or freezer (depending on chemicophysical properties ) that bears appropriate label. An inventory should be kept, showing quantity of carcinogen & date it was acquired Facilities for dispensing should be contiguous to storage area.

pKa = -0.8 to 1.6

Weighs 13.9 lb per gal /Chromic acid soln/|Deliquescent /Anhydrous chromic acid/

Attacks most metals, particularly copper and brass. Attacks cloth, leather, and some plastics.

II

5

UN 1463/1755

45-46-9-24/25-26-35-42/43-48/23-62-50/53

53-45-60-61

O, T+, N

Provision to contain effluent from fire extinguishing. Separated from combustible substances, reducing agents, bases and food and feedstuffs. Well closed. Store in an area without drain or sewer access.

P201, P202, P260, P261, P264, P270, P271, P272, P280, P281, P284, P285, P301+P310, P301+P330+P331, P302+P352, P303+P361+P353, P304+P340, P304+P341, P305+P351+P338, P308+P313, P310, P312, P314, P320, P321, P322, P330, P333+P313, P342+P311, P361, P363, P403+P233, P405, P501

H301

Generators of waste (equal to or greater than 100 kg/mo) containing this contaminant, EPA hazardous waste number D007, must conform with USEPA regulations in storage, transportation, treatment and disposal of waste.|The following wastewater treatment technologies have been investigated for chromic acid: Concentration process: Reverse Osmosis.|SRP: Wastewater from contaminant suppression, cleaning of protective clothing/equipment, or contaminated sites should be contained and evaluated for subject chemical or decomposition product concentrations. Concentrations shall be lower than applicable environmental discharge or disposal criteria. Alternatively, pretreatment and/or discharge to a permitted wastewater treatment facility is acceptable only after review by the governing authority and assurance that "pass through" violations will not occur. Due consideration shall be given to remediation worker exposure (inhalation, dermal and ingestion) as well as fate during treatment, transfer and disposal. If it is not practicable to manage the chemical in this fashion, it must be evaluated in accordance with EPA 40 CFR Part 261, specifically Subpart B, in order to determine the appropriate local, state and federal requirements for disposal.|PRECAUTIONS FOR "CARCINOGENS": There is no universal method of disposal that has been proved satisfactory for all carcinogenic compounds & specific methods of chem destruction ... published have not been tested on all kinds of carcinogen-containing waste. ... summary of avail methods & recommendations ... /given/ must be treated as guide only. /Chemical Carcinogens/|For more Disposal Methods (Complete) data for CHROMIC ACID (8 total), please visit the HSDB record page.

Dangerously reactive. Incompatible with acetic acid, acetic anhydride, tetrahydronaphthalene, acetone, alcohols, alkali metals, ammonia, arsenic, bromine pentafluoride, butyric acid, n,n-dimethylformamide, hydrogen sulfide, peroxyformic acid, phosphorus, potassium hexacyanoferrate, pyridine, selenium, sodium, sulfur & many other materials.|Combustible, organic, or other readily oxidizable materials (paper, wood, sulfur, aluminum, plastics, etc.); corrosive to metals. /Chromic acid and chromates/

Carcinogens, Corrosives, Reactive - 1st degree

|Danger|H271 (26%): May cause fire or explosion; strong Oxidizer [Danger Oxidizing liquids; Oxidizing solids]|P201, P202, P210, P220, P221, P260, P261, P262, P264, P270, P271, P272, P273, P280, P281, P283, P284, P285, P301+P310, P301+P330+P331, P302+P350, P302+P352, P303+P361+P353, P304+P340, P304+P341, P305+P351+P338, P306+P360, P308+P313, P310, P314, P320, P321, P322, P330, P333+P313, P342+P311, P361, P363, P370+P378, P371+P380+P375, P391, P403+P233, P405, and P501|Aggregated GHS information provided by 100 companies from 10 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.|H301: Toxic if swallowed [Danger Acute toxicity, oral]|P201, P202, P260, P261, P264, P270, P271, P272, P280, P281, P284, P285, P301+P310, P301+P330+P331, P302+P352, P303+P361+P353, P304+P340, P304+P341, P305+P351+P338, P308+P313, P310, P312, P314, P320, P321, P322, P330, P333+P313, P342+P311, P361, P363, P403+P233, P405, and P501

Employees should be provided with and required to use impervious clothing, gloves, face shields (eight-inch minimum), and other appropriate protective clothing necessary to prevent any possiblity of skin contact with solids or liquids containing chromic acid or chromates.|Wear appropriate personal protective clothing to prevent skin contact. /Chromic acid and chromates/|Wear appropriate eye protection to prevent eye contact. /Chromic acid and chromates/|Eyewash fountains should be provided in areas where there is any possibility that workers could be exposed to the substances; this is irrespective of the recommendation involving the wearing of eye protection. /Chromic acid and chromates/|For more Personal Protective Equipment (PPE) (Complete) data for CHROMIC ACID (10 total), please visit the HSDB record page.

If material involved in fire: Extinguish fire using agent suitable for type of surrounding fire (Material itself does not burn or burns with difficulty). Use water in flooding quantities as fog. Cool all affected contrainers with flooding quantities of water. Apply water from as far a distrance as possible. /Chromic acid solution/

PRECAUTIONS FOR "CARCINOGENS": A high-efficiency particulate arrestor (HEPA) or charcoal filters can be used to minimize amt of carcinogen in exhausted air ventilated safety cabinets, lab hoods, glove boxes or animal rooms ... Filter housing that is designed so that used filters can be transferred into plastic bag without contaminating maintenance staff is avail commercially. Filters should be placed in plastic bags immediately after removal ... The plastic bag should be sealed immediately ... The sealed bag should be labelled properly ... Waste liquids ... should be placed or collected in proper containers for disposal. The lid should be secured & the bottles properly labelled. Once filled, bottles should be placed in plastic bag, so that outer surface ... is not contaminated ... The plastic bag should also be sealed & labelled. ... Broken glassware ... should be decontaminated by solvent extraction, by chemical destruction, or in specially designed incinerators. /Chemical Carcinogens/|Environmental considerations: Land spill: Dig a pit, pond, lagoon, holding area to contain liquid or solid material. /SRP: If time permits, pits, ponds, lagoons, soak holes, or holding areas should be sealed with an impermeable flexible membrane liner./ Dike surface flow using soil, sand bags, foamed polyurethane, or foamed concrete. Absorb bulk liquid with fly ash or cement powder. Neutralize with agricultural lime (CaO), crushed limestone (CaCO3) or sodium bicarbonate (NaHCO3).|Environmental considerations: Water spill: Neutralize with agricultural lime (CaO), crushed limestone (CaCO3), or sodium bicarbonate (NaHCO3). Adjust pH to neutral (pH=7). Use mechanical dredges or lifts to remove immobilized masses of pollutants and precipitates. /Chromic acid solution/|Environmental considerations: Air spill: Apply water spray or mist to knock down vapors. Vapor knockdown water is corrosive or toxic and should be diked for containment. /Chromic acid solution/

If employees' clothing may have become contaminated with solids or liquids containing chromic acid or chromates, employees should change into uncontaminated clothing before leaving the work premises.|Clothing contaminated with chromic acid or chromates should be placed in closed containers for storage until it can be discarded or until provision is made for the removal of substance from the clothing. If the clothing is to be laundered or otherwise cleaned to remove the chromic acid or chromates, the person performing the operation should be informed of chromic acid or chromates hazardous properties.|Where there is any possibility of exposure of an employee's body to solids or liquids containing chromic acid or chromates, facilities for quick drenching of the body should be provided within the immediate work area for emergency use.|Non-impervious clothing which becomes contaminated with chromic acid or chromates should be removed immediately and not reworn until the substance is removed from the clothing.|For more Preventive Measures (Complete) data for CHROMIC ACID (23 total), please visit the HSDB record page.

/GUIDE 154: SUBSTANCES - TOXIC AND/OR CORROSIVE (NON-COMBUSTIBLE)/ Health: TOXIC; inhalation, ingestion, or skin contact with material may cause severe injury or death. Contact with molten substance may cause severe burns to skin and eyes. Avoid any skin contact. Effects of contact or inhalation may be delayed. Fire may produce irritating, corrosive and/or toxic gases. Runoff from fire control or dilution water may be corrosive and/or toxic and cause pollution. /Chromic acid, solution/|/GUIDE 154: SUBSTANCES - TOXIC AND/OR CORROSIVE (NON-COMBUSTIBLE)/ Fire or Explosion: Non-combustible, substance itself does not burn but may decompose upon heating to produce corrosive and/or toxic fumes. Some are oxidizers and may ignite combustibles (wood, paper, oil, clothing, etc.). Contact with metals may evolve flammable hydrogen gas. Containers may explode when heated. /Chromic acid, solution/|/GUIDE 154: SUBSTANCES - TOXIC AND/OR CORROSIVE (NON-COMBUSTIBLE)/ Public Safety: CALL Emergency Response Telephone Number ... As an immediate precautionary measure, isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters (75 feet) for solids. Keep unauthorized personnel away. Stay upwind. Keep out of low areas. Ventilate enclosed areas. /Chromic acid, solution/|/GUIDE 154: SUBSTANCES - TOXIC AND/OR CORROSIVE (NON-COMBUSTIBLE)/ Protective Clothing: Wear positive pressure self-contained breathing apparatus (SCBA). Wear chemical protective clothing that is specifically recommended by the manufacturer. It may provide little or no thermal protection. Structural firefighters' protective clothing provides limited protection in fire situations ONLY; it is not effective in spill situations where direct contact with the substance is possible. /Chromic acid, solution/|For more DOT Emergency Guidelines (Complete) data for CHROMIC ACID (8 total), please visit the HSDB record page.

No person may /transport,/ offer or accept a hazardous material for transportation in commerce unless that person is registered in conformance ... and the hazardous material is properly classed, described, packaged, marked, labeled, and in condition for shipment as required or authorized by ... /the hazardous materials regulations (49 CFR 171-177)./|The International Air Transport Association (IATA) Dangerous Goods Regulations are published by the IATA Dangerous Goods Board pursuant to IATA Resolutions 618 and 619 and constitute a manual of industry carrier regulations to be followed by all IATA Member airlines when transporting hazardous materials.|The International Maritime Dangerous Goods Code lays down basic principles for transporting hazardous chemicals. Detailed recommendations for individual substances and a number of recommendations for good practice are included in the classes dealing with such substances. A general index of technical names has also been compiled. This index should always be consulted when attempting to locate the appropriate procedures to be used when shipping any substance or article.|PRECAUTIONS FOR "CARCINOGENS": Procurement ... of unduly large amt ... should be avoided. To avoid spilling, carcinogens should be transported in securely sealed glass bottles or ampoules, which should themselves be placed inside strong screw-cap or snap-top container that will not open when dropped & will resist attack from the carcinogen. Both bottle & the outside container should be appropriately labelled. ... National post offices, railway companies, road haulage companies & airlines have regulations governing transport of hazardous materials. These authorities should be consulted before ... material is shipped. /Chemical Carcinogens/|PRECAUTIONS FOR "CARCINOGENS": When no regulations exist, the following procedure must be adopted. The carcinogen should be enclosed in a securely sealed, watertight container (primary container), which should be enclosed in a second, unbreakable, leakproof container that will withstand chem attack from the carcinogen (secondary container). The space between primary & secondary container should be filled with absorbent material, which would withstand chem attack from the carcinogen & is sufficient to absorb the entire contents of the primary container in the event of breakage or leakage. Each secondary container should then be enclosed in a strong outer box. The space between the secondary container & the outer box should be filled with an appropriate quantity of shock-absorbent material. Sender should use fastest & most secure form of transport & notify recipient of its departure. If parcel is not received when expected, carrier should be informed so that immediate effort can be made to find it. Traffic schedules should be consulted to avoid ... arrival on weekend or holiday ... /Chemical Carcinogens/

A powerful irritant of skin, eyes, & mucous membranes. Can cause a dermatitis, bronchoasthma, "chrome holes", damage to the eyes.

Permissible Exposure Limit: Table Z-2 Acceptable Ceiling Concentration: 1 mg/10 cu m. /Chromic acid and chromates/

NIOSH considers chromic acid to be a potential occupational carcinogen. /Chromic acid and chromates/|NIOSH usually recommends that occupational exposures to carcinogens be limited to the lowest feasible concentration. /Chromic acid and chromates/|Recommended Exposure Limit: 8 Hour Time-Weighted Average: 0.0002 mg/cu m. /as Cr; Chromic acid and chromates/|The NIOSH Recommended Exposure Limit (8-hour TWA) is 0.0002 mg Cr(VI)/cu m for all hexavalent chromium (Cr(VI)) compounds. NIOSH considers all Cr(VI) compounds (including chromic acid, tert-butyl chromate, zinc chromate, and chromyl chloride) to be potential occupational carcinogens. The NIOSH Recommended Exposure Limit (8-hour TWA) is 0.5 mg Cr/cu m for chromium metal and chromium(II) and chromium(III) compounds. /Chromic Acid and Chromates (as CrO3), Chromium(II) and Chromium(III) Compounds (as Cr), and Chromium Metal (as Cr)/

Chromium has been designated as a hazardous air pollutant under section 112 of the Clean Air Act. /Chromium/

D007; A waste containing chromium may or may not be characterized as a hazardous waste following testing by the Toxicity Characteristic Leaching Procedure as prescribed by the Resource Conservation and Recovery Act (RCRA) regulations. /Chromium/

Persons in charge of vessels or facilities are required to notify the National Response Center (NRC) immediately, when there is a release of this designated hazardous substance, in an amount equal to or greater than its reportable quantity of 10 lb or 4.54 kg. The toll free number of the NRC is (800) 424-8802. The rule for determining when notification is required is stated in 40 CFR 302.4 (section IV. D.3.b).

D007; A solid waste containing chromium may or may not become characterized as a hazardous waste when subjected to the Toxicity Characteristic Leaching Procedure listed in 40 CFR 261.24, and if so characterized, must be managed as a hazardous waste. /Chromium/

IDENTIFICATION AND USE: Chromic acid forms dark purplish-red crystals. It is used as photographic chemical; aluminum anodizing reagent; chrome electroplating/zinc colorless conversion coatings reagent; side-chain oxidation reagent, and wood preservative. HUMAN EXPOSURE AND TOXICITY: Repeated or prolonged exposure to chromic acid or chromate dust or mist may cause an ulceration and perforation of the nasal septum. Respiratory irritation may occur with symptoms resembling asthma. Liver damage with yellow jaundice has been reported. Prolonged or repeated exposure of the skin may cause a skin rash. Allergic skin rash may also occur. Contact causes severe eye injury characterized by infiltration, vascularization, and opacification of the cornea. Full-thickness skin burns covering as little as 1% of the body surface area may lead to irreversible acute tubular necrosis secondary to acute chromium intoxication. The mortality rate is high if the burned area exceeds approximately 10% of the body surface. The correlation with duration of chrome bath work associated with exposure to chromium acid was positive only for cancers of the lung and bronchus in male workers. It was experimentally and epidemiologically confirmed that hexavalent chromium compounds act as carcinogens and cause specific biological effects on the respiratory system. These characteristics of hexavalent compounds might be attributable to the strong oxidizing potency and/or high permeability through the cell membrane. Furthermore, hexavalent compounds might be entirely different in biological action from trivalent compounds which are chemically most stable. ANIMAL STUDIES: There is limited evidence in experimental animals for the carcinogenicity of chromic acid. There was an increased incidence in abnormalities (cleft palate, cleft sternum, perforated sternum) in developmental studies in mice. In CHO cells, there was a significant increase in SCE with CrVI compounds. In the Ames test there was a dose-response for increase in revertant colonies for all CrVI compounds at 10-200 ug/plate with TA1537, TA98 and TA100. Addition of S9 did not affect mutation incidence. In other studies, when tested in Salmonella typhimurium strains TA1537, TA1538, TA98 and TA100 the S9 mix decreased the mutagenicity of CrVI compounds.

Severe poisoning follows the ingestion of as little as 1 to 2 g of compounds containing hexavalent chromium ion. The lethal dose is approximately 6 g.

LD50 Dog oral 330 mg/kg|LD100 Rat oral 350 mg/kg /From table/

NIOSH (NOES Survey 1981-1983) has statistically estimated that 126,538 workers (19,927 of these were female) were potentially exposed to chromic acid in the US(1).|Chromic acid fumes ... can affect the body if they are inhaled or come in contact with the eyes or skin. They can also affect the body if they are swallowed.|Skin problems caused by chromic acid are associated with chrome baths in the electroplating industry. /From table/|Chrome platers are exposed to chromium trioxide (CrO3) & its aqueous soln, chromic acid (H2CrO4). There is no convincing evidence that these highly corrosive soluble chromates pose a lung cancer risk among chrome platers, although the suggestion of an increased risk has been reported. Today, however, there are additives that reduce the escape of mist by reducing bubbling at electrodes, & newer plating methods, including electrolysis plating, & other control measures have greatly reduced exposures to these chromates.|For more Probable Routes of Human Exposure (Complete) data for CHROMIC ACID (6 total), please visit the HSDB record page.

Severe poisoning follows the ingestion of as little as 1 to 2 g of compounds containing hexavalent chromium ion. The lethal dose is approximately 6 g.

Inhalation of highly water-soluble hexavalent chromium salts, such as chromic acid, ... may result in systemic absorption.|Absorption of inhaled chromium cmpds takes place in the lung via transfer across cell membranes and in the GI tract from particles cleared from the lungs. Absorption after oral exposure in humans varies from essentially none for the highly insoluble chromium(III) cmpd chromic oxide, to 0.5-2.0% for chromium(III) cmpds in the diet, to approx 2-10% for chromium(VI) as potassium chromate. Dermal absorption depends on the physical and chemical properties of the cmpd, the vehicle, and the integrity of the skin. Concentrated soln of chromium(VI) cmpds such as potassium chromate can cause chemical burns and facilitate absorption. /Chromium cmpds/

The strong oxidizing potential of chromium(VI) compounds explain much of their irritating and toxic properties. /Chromium(VI) compounds/

/EXPL/ Treatment of /chromic acid burns/ is directed at immediate, copious irrigation of all exposed areas. If irrigation cannot be achieved within seconds to minutes, full thickness burns and cutaneous absorption of the chromium ion will result. A variety of compounds have been recommended for limiting the toxic effects of the hexavalent chromium ion, including dressings of sodium thiosulfate, sodium citrate, 10% vitamin C gel to convert Cr(+6) to (Cr+3), lactate, and sodium metabisulfite. Recommended systemic antidotes include sodium thiosulfate, dimercaprol, calcium disodium ethylenediaminetetraacetic acid, and n-acetyl-cysteine. Some have advocated a prompt, deep, tangential incision of all contaminated tissues to prevent systemic ion penetration. All these approaches must be regarded as experimental.|Immediate first aid: Ensure that adequate decontamination has been carried out. If patient is not breathing, start artificial respiration, preferably with a demand-valve resuscitator, bag-valve-mask device, or pocket mask, as trained. Perform CPR as necessary. Immediately flush contaminated eyes with gently flowing water. Do not induce vomiting. If vomiting occurs, lean patient forward or place on left side (head-down position, if possible) to maintain an open airway and prevent aspiration. Keep patient quiet and maintain normal body temperature. Obtain medical attention. /Inorganic acids and related compounds/|Basic treatment: Establish a patent airway (oropharyngeal or nasopharyngeal airway, if needed). Suction if necessary. Watch for signs of respiratory insufficiency and assist respirations if needed. Administer oxygen by nonrebreather mask at 10 to 15 L/min. Monitor for pulmonary edema and treat if necessary ... . Monitor for shock and treat if necessary ... . For eye contamination, flush eyes immediately with water. Irrigate each eye continuously with 0.9% saline (NS) during transport ... . Do not use emetics. Activated charcoal is not effective. For ingestion, rinse mouth and administer 5 mL/kg up to 200 mL of water for dilution if the patient can swallow, has a strong gag reflex, and does not drool ... . Do not attempt to neutralize because of exothermic reaction. Cover skin burns with dry, sterile dressings after decontamination ... . /Inorganic acids and related compounds/|Advanced treatment: Consider orotracheal or nasotracheal intubation for airway control in the patient who is unconscious, has severe pulmonary edema, or is in severe respiratory distress. Early intubation, at the first sign of upper airway obstruction, may be necessary. Positive-pressure ventilation techniques with a bag valve mask device may be beneficial. Consider drug therapy for pulmonary edema ... . Consider administering a beta agonist such as albuterol for severe bronchospasm ... . Monitor cardiac rhythm and treat arrhythmias as necessary ... . Start IV administration of D5W /SRP: "To keep open", minimal flow rate/. Use 0.9% saline (NS) or lactated Ringer's(LR) if signs of hypovolemia are present. For hypotension with signs of hypovolemia, administer fluid cautiously. Consider vasopressors if patient is hypotensive with a normal fluid volume. Watch for signs of fluid overload ... . Use proparacaine hydrochloride to assist eye irrigation ... . /Inorganic acids and related compounds/|For more Antidote and Emergency Treatment (Complete) data for CHROMIC ACID (8 total), please visit the HSDB record page.

/SIGNS AND SYMPTOMS/ Repeated or prolonged exposure to chromic acid or chromate dust or mist may cause an ulceration & perforation of the nasal septum. Respiratory irritation may occur with symptoms resembling asthma. Liver damage with yellow jaundice has been reported. Prolonged or repeated exposure of the skin may cause a skin rash. Allergic skin rash may also occur.|/SIGNS AND SYMPTOMS/ Contact causes severe injury characterized by infiltration, vascularization, & opacification of the cornea. Chronic exposure to fine droplets in the air from electroplating baths or transfer to the eyes on the fingers causes chronic conjunctival inflammation & in rare instances a brown band in the superficial layers of the cornea.|/SIGNS AND SYMPTOMS/ Splash contact of concentrated strong acids, such as ... chromic acid ... can prove as severely & devastatingly injurious to the eye as splashes of strong alkalies.|/SIGNS AND SYMPTOMS/ Symptomatology (after ingestion or skin contact): 4) Circulatory collapse with clammy skin, weak and rapid pulse, shallow respirations, and scanty urine. Circulatory shock is often the immediate cause of death. 5) Asphyxial death due to glottic edema. 6) Late esophageal, gastric and pyloric strictures and stenoses, which may require major surgical repair, should be anticipated. Signs of obstruction commonly appear within a few weeks but may be delayed for months and even years. Permanent scars may also appear in the cornea, skin and oropharynx. 7) Uncorrected circulatory collapse of several hours' duration may lead to renal failure and ischemic lesions in the liver and heart.|For more Human Toxicity Excerpts (Complete) data for CHROMIC ACID (12 total), please visit the HSDB record page.

chromic acid

Wood preservatives (72%); metal finishing (22%); misc, including magnetic material and catalysis (6%)|DEMAND: (1998) 47,000 short tons; (1999) 48,100 short tons; (2003) 52,600 short tons

USEPA/OPP Pesticide Code 021101; Trade Names: Chromic acid flake.|Grades: technical; CP (chemically pure).|Osmose K-33 (60%) Wood Preservative (Osmose, Inc.): Active ingredient: arsenic oxide 20.0%, chromic acid 29.9% and cupric oxide 10.5%.|Osmose ACC 50% Wood Preservative (Osmose, Inc.): Active ingredient: chromic acid 35.46% and cupric oxide 14.07%.|For more Formulations/Preparations (Complete) data for CHROMIC ACID (11 total), please visit the HSDB record page.

All other basic inorganic chemical manufacturing|Chromic acid (H2CrO4): ACTIVE|R - indicates a substance that is the subject of a TSCA section 6 risk management rule.|/Chromic acid:/ This important acid is known also as chromium trioxide. The technical grade is obtainable from primary producers in an anhydrous form as small dark red flakes containing 99% CrO3. Like all chromates and dichromates, its chromium is in the hexavalent state. It is very soluble and strongly reactive both as an acid and as an oxidizing agent ... .

Particulate filter collection; H2S04 and diphenylcarbazide work-up; Colorimetric spectroscopy analysis. /Chromic acid and chromates/|NIOSH Method 7600. Chromium, Hexavalent. Concentrations of chromic acid as CrO4- 2/diphenylazide complex measured using UV/VIS spectrophotometry. Detection limit = 0.05 ug/sample.|NIOSH Method 7604. Chromium, Hexavalent. Concentrations of chromic acid as CrO4-2 ion measured using ion chromatography with conductivity detection. Detection limit = 3.5 ug/sample.

The levels of trace element in hair of 9 yr old human subject was detn 50, 240, and 690 days after acute chromic acid poisoning (accidental immersion of 2 legs into dichromate waste). The half life of Cr in hair was 540 days. Significant decrease of Ca level and increase of Fe and Zn levels seen on day 54 restored to normal level on day 690.

Fire Hazards -> Carcinogens, Corrosives, Reactive - 1st degree