Chromic acid

CAS: 7738-94-5

Overview

Chromic acid (CAS 7738-94-5 ) is a strong inorganic oxidizing acid used primarily in metal surface treatment and industrial finishing operations. In practice, it exists as an aqueous solution of chromium trioxide and is sourced and handled in that form by most industrial buyers.

In metal finishing and electroplating, chromic acid is the active constituent of hard chrome and decorative chrome plating baths. It produces wear-resistant and corrosion-inhibiting coatings on various industrial components.

Anodizing operations for aluminum use chromic acid electrolyte processes where a thin, corrosion-resistant oxide layer is required. This is particularly critical in specialized aerospace and defense applications.

In the textile and leather industries, it functions as an oxidizing bleach and surface modifier. This improves dye uptake and prepares fiber substrates for various types of downstream processing.

Mining and metals operations use it in passivation treatments to protect metal surfaces against oxidation during storage and transit. This ensures the integrity of the metal before it reaches the end user.

Chromic acid is supplied as an aqueous solution, with chromium trioxide dissolved in water to produce the active acid. Technical grade is the standard commercial form for most industrial applications.

Concentration is typically specified by the buyer according to specific process requirements. Industrial supply is subject to regulatory controls in many jurisdictions due to hexavalent chromium content.

Buyers should confirm compliance documentation alongside standard quality specifications. Proper handling and storage protocols must be maintained to ensure safety and environmental protection during use.

Physical Properties

Melting Point	196 °C
Boiling Point	250 °C (decomposes)
Density	1.67-2.82 g/cm³
Appearance	Chromic acid is a dark purplish-red odorless flakes or crystalline powder
Color	Clear, orange
Odor	Odorless
Form	Liquid
Water Solubility	HIGHLY Soluble
pH	3.03(1 mM solution);2.33(10 mM solution);2.06(100 mM solution)

Safety & Handling

Danger GHS03 GHS05 GHS06 GHS07 GHS08 GHS09 Hazard Statements H271 May cause fire or explosion; strong Oxidizer H300 Fatal if swallowed H301 Toxic if swallowed H310 Fatal in contact with skin H311 Toxic in contact with skin H312 Harmful in contact with skin H314 Causes severe skin burns and eye damage H317 May cause an allergic skin reaction H318 Causes serious eye damage H330 Fatal if inhaled H334 May cause allergy or asthma symptoms or breathing difficulties if inhaled H340 May cause genetic defects H341 Suspected of causing genetic defects H350 May cause cancer H361 Suspected of damaging fertility or the unborn child H372 Causes damage to organs through prolonged or repeated exposure H400 Very toxic to aquatic life H410 Very toxic to aquatic life with long lasting effects Precautionary Statements P203 Obtain, consult and follow expert instructions for use. P210 Keep away from heat, hot surfaces, sparks, open flames and other ignition sources. No smoking. P220 Keep away from clothing and other combustible materials. P233 Keep container tightly closed. P260 Do not breathe dust/fume/gas/mist/vapours/spray. P261 Avoid breathing dust/fume/gas/mist/vapours/spray. P262 Do not get in eyes, on skin, or on clothing. P264 Wash … thoroughly after handling. P270 Do not eat, drink or smoke when using this product. P271 Use only outdoors or in a well-ventilated area. P272 Contaminated work clothing should not be allowed out of the workplace. P273 Avoid release to the environment. P280 Wear protective gloves/protective clothing/eye protection/face protection. P283 Wear fire-resistant/flame-retardant clothing. P284 In case of inadequate ventilation wear respiratory protection. P316 Get emergency medical help immediately. P317 Get emergency medical help. P318 IF exposed or concerned, get medical advice. P319 Get medical advice/attention if you feel unwell. P320 Specific treatment is urgent (see … on this label). P321 Specific treatment (see … on this label). P330 Rinse mouth. P363 Wash contaminated clothing before reuse. P391 Collect spillage. P403 Store in a well-ventilated place. P405 Store locked up. P420 Store away from other materials. P501 Dispose of contents/container in accordance with local regulations. P264+P265 Wash … thoroughly after handling. P301+P316 Get emergency medical help immediately. P302+P352 IF ON SKIN: Wash with plenty of water. P304+P340 IF INHALED: Remove person to fresh air and keep comfortable for breathing. P306+P360 IF ON CLOTHING: Rinse immediately contaminated clothing and skin with plenty of water before removing clothes. P333+P317 Get emergency medical help. P342+P316 Get emergency medical help immediately. P361+P364 Take off immediately all contaminated clothing and wash it before reuse. P362+P364 Take off contaminated clothing and wash it before reuse. P370+P378 Use … for extinction. P403+P233 Store in a well-ventilated place. Keep container tightly closed. P301+P330+P331 Rinse mouth. Do NOT induce vomiting. P302+P361+P354 IF ON SKIN: Take off immediately all contaminated clothing. Rinse skin with water/shower. P305+P354+P338 IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing. P371+P380+P375 Evacuate area.

Trade & Regulatory

UN Number

1463

Other Names

Industries

Textile, Leather & Paper Mining & Metals