Cyclohexa-2,5-diene-1,4-dione

Cyclohexa-2,5-diene-1,4-dione is an organic compound with the molecular formula C6H4O2 and CAS number 106-51-4. Also known as para-benzoquinone or 1,4-benzoquinone, it is a yellow crystalline solid with a molecular weight of 108.09 g/mol. This quinone derivative features a six-membered ring with two ketone groups in para position, making it an important intermediate in organic synthesis and various industrial applications.

Cyclohexa-2,5-diene-1,4-dione appears as yellow crystalline needles or prisms at room temperature. It has a characteristic pungent, chlorine-like odor that is detectable at low concentrations. The compound is moderately soluble in water and readily soluble in organic solvents such as ethanol, ether, and benzene. It sublimates readily at room temperature and has a relatively low melting point, making it volatile under normal conditions.

Cyclohexa-2,5-diene-1,4-dione serves as a crucial intermediate in organic synthesis, particularly in the production of hydroquinone and other quinone derivatives. It is widely used in the manufacture of dyes, pigments, and photographic chemicals. The compound also finds applications in polymerization inhibitors, fungicides, and as an oxidizing agent in various chemical processes. Additionally, it is employed in the production of certain pharmaceuticals and fine chemicals.

Cyclohexa-2,5-diene-1,4-dione requires careful handling due to its Acute Tox. 3 classification and skin/eye irritant properties. Always wear appropriate personal protective equipment including chemical-resistant gloves, safety goggles, and protective clothing. Work in well-ventilated areas or under fume hoods to avoid inhalation exposure. Prevent skin and eye contact, and avoid generating dust or vapors. Wash hands thoroughly after handling and ensure emergency eyewash and shower facilities are readily accessible.

Cyclohexa-2,5-diene-1,4-dione should be stored in tightly sealed containers in a cool, dry, well-ventilated area away from direct sunlight and heat sources. Keep away from incompatible materials such as strong reducing agents, alkalis, and organic materials that may cause unwanted reactions. Store in original containers with proper labeling and maintain temperatures below 25°C to prevent sublimation. Ensure storage areas are equipped with appropriate spill containment measures and restrict access to authorized personnel only.

In case of skin contact with cyclohexa-2,5-diene-1,4-dione, immediately remove contaminated clothing and wash the affected area thoroughly with soap and water for at least 15 minutes. For eye contact, rinse immediately with clean water for at least 15 minutes while holding eyelids open. If inhaled, move the person to fresh air and keep at rest. If ingested, do not induce vomiting and rinse mouth with water. Seek immediate medical attention in all cases of exposure and provide safety data sheet information to medical personnel.

Cyclohexa-2,5-diene-1,4-dione must be disposed of as hazardous waste according to local, national, and international regulations. Contact licensed waste disposal companies for proper collection and treatment. The compound cannot be disposed of through normal waste streams due to its toxic and environmentally hazardous properties. Ensure proper packaging and labeling for waste collection, and maintain disposal records for regulatory compliance. Consider waste minimization and recovery options where technically and economically feasible.

Cyclohexa-2,5-diene-1,4-dione is classified as ADR Class 6.1 (Toxic substances), Packing Group II, requiring specific transport regulations compliance. Use appropriate UN-specification packaging designed for toxic substances and ensure proper hazard labeling with GHS06 and GHS09 pictograms. Transport vehicles must carry appropriate emergency equipment and documentation including safety data sheets. Only authorized and trained personnel should handle transportation, and emergency response procedures must be readily available during transit.

Cyclohexa-2,5-diene-1,4-dione is subject to comprehensive chemical regulations including REACH registration requirements in Europe and CLP classification as a hazardous substance. It is not currently listed as a Substance of Very High Concern (SVHC), but its Acute Tox. 3 and environmental hazard classifications impose strict handling, labeling, and safety data sheet requirements. Users must comply with occupational exposure limits, waste disposal regulations, and transport classifications under ADR for safe and legal use.

Cyclohexa-2,5-diene-1,4-dione is available through OYSI, a trusted European distributor of technical chemicals serving industrial customers across Europe. OYSI provides high-quality chemical products with proper documentation, safety data sheets, and regulatory compliance support. As a specialized chemical distributor, OYSI ensures reliable supply chains and technical support for professional users requiring cyclohexa-2,5-diene-1,4-dione for industrial applications, research, or manufacturing processes.