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Chemical Name: Hydroquinone
Common Names: 1,4-Benzenediol, Benzene-1,4-diol, Quinol
CAS Number: 123-31-9
Recommended Use: Antioxidant, photographic developer, polymerization inhibitor, skin lightening agent
Manufacturer Contact: Emergency phone available through CHEMTREC, reach out to supplier for specific numbers
Molecular Formula: C6H6O2
Molecular Weight: 110.11 g/mol
Hazard Classification: Acute toxicity (oral, dermal, inhalation), Eye irritation, Skin sensitization, Carcinogenicity (group 3, not classifiable as per IARC)
Signal Word: Danger
Hazard Statements: Toxic if swallowed, may cause an allergic skin reaction, causes serious eye irritation, harmful if inhaled, suspected of causing cancer
Pictogram: Skull and crossbones, exclamation mark, health hazard
Precautionary Statements: Avoid breathing dust, wear protective clothing and eye protection, wash hands thoroughly after handling, keep container tightly closed
Substance: Hydroquinone
Synonym: 1,4-Dihydroxybenzene
Concentration: 99-100% (pure), technical grades may contain small amounts of impurities or stabilizers
Impurities: May contain trace impurities or moisture depending on supplier, usually not significant for most commercial uses
Inhalation: Move person to fresh air, keep at rest in a position comfortable for breathing, seek immediate medical attention if symptoms like coughing or shortness of breath appear
Skin Contact: Remove contaminated clothing, wash skin with plenty of soap and water for at least 15 minutes, seek medical advice if irritation, redness, or sensitization show up
Eye Contact: Rinse cautiously with water for several minutes, remove contact lenses if present and easy to do, continue rinsing until medical help gets involved
Ingestion: Rinse mouth, do not induce vomiting, provide water if alert, get medical attention as soon as possible
Symptoms and Effects: Irritation, redness, headache, dizziness, abdominal pain, cyanosis, methemoglobinemia in severe poisoning
Suitable Extinguishing Media: Water spray, dry chemical, carbon dioxide, foam
Unsuitable Media: Strong jet of water can scatter powder and may spread fire
Special Hazards: Combustion produces carbon monoxide, carbon dioxide, toxic fumes, may release irritating or hazardous vapors
Protective Equipment: Firefighters should wear self-contained breathing apparatus and full protective gear
Advice for Firefighters: Keep containers cool with water spray, avoid inhalation of fumes, fight fire from safe distance
Personal Precautions: Evacuate area, ensure adequate ventilation, avoid breathing dust, use personal protective equipment
Environmental Precautions: Prevent further leakage or spillage if safe, keep out of sewers, drains, and waterways
Spill Clean-Up: Use non-sparking tools, clean up spill promptly, collect spillage into suitable containers, dispose of according to local regulations
Decontamination Methods: Wash area with plenty of water and detergent, ventilate affected area after spill clean-up
Safe Handling: Handle in well-ventilated areas, wear protective gloves and safety goggles to prevent contact, prevent formation of dust
Storage Conditions: Store in dry, well-ventilated space away from heat, ignition sources, and direct sunlight, keep container tightly closed
Incompatible Materials: Strong oxidizers, strong bases, mineral acids, iron, metals such as silver and lead
Other Precautions: Keep away from food and beverages, do not reuse container for other chemicals, use only with proper grounding and bonding to prevent static buildup
Occupational Exposure Limits (OEL): OSHA PEL: 2 mg/m³ TWA, ACGIH TLV: 1 mg/m³ TWA, NIOSH REL: 2 mg/m³ TWA
Engineering Controls: Local exhaust ventilation or general dilution ventilation, eye wash stations and emergency showers
Personal Protective Equipment (PPE): Impervious gloves (nitrile, neoprene), chemical splash goggles, lab coat or apron, properly fitted NIOSH-approved respirator for dust
Hygiene Measures: Do not eat, drink, or smoke while handling, wash hands thoroughly after use, remove contaminated clothing before entering eating areas
Appearance: White crystalline solid or powder
Odor: Slight aromatic odor
Melting Point: 172°C (342°F)
Boiling Point: 287°C (549°F) (decomposes on boiling)
Flash Point: 165°C (329°F, closed cup)
Solubility: Soluble in hot water, alcohol, ether
Vapor Pressure: 1 mmHg at 132°C
Density: 1.33 g/cm³ at 20°C
pH: Slightly acidic when dissolved in water
Partition Coefficient (log Kow): 0.59
Auto-Ignition Temperature: 530°C (986°F)
Chemical Stability: Tends to oxidize slowly in air turning brown, especially under light
Conditions to Avoid: Heat, open flames, oxidizing conditions, moisture, incompatible chemicals
Materials to Avoid: Strong oxidizers (such as nitric acid, hydrogen peroxide), alkalis, iron salts, lead, silver, chlorates
Hazardous Decomposition: Produces carbon monoxide, carbon dioxide, quinones and other toxic gases under fire or decomposition conditions
Polymerization: Does not undergo hazardous polymerization under normal conditions
Routes of Exposure: Inhalation, ingestion, skin contact, eye contact
Acute Toxicity Data: Oral LD50 (rat): 320 mg/kg, Dermal LD50 (rabbit): 500 mg/kg
Chronic Effects: Possible effects on kidney, liver, blood, methemoglobinemia, allergic skin reactions, dermatitis
Carcinogenicity: Not classified as carcinogen by IARC, ACGIH A3 (confirmed animal carcinogen with unknown relevance to humans)
Reproductive Toxicity: No adequate data on reproductive effects in humans
Mutagenicity/Genotoxicity: Evidence of mutagenic effects in experimental settings
Sensitization: Can cause allergic reactions and sensitization of skin
Symptoms of Overexposure: Headache, dizziness, nausea, vomiting, blue lips or skin (cyanosis), arrhythmia, convulsions
Ecotoxicity: Toxic to aquatic organisms, may cause long-term adverse effects in aquatic environments
Aquatic Toxicity: LC50 (fish, 96h): 0.044 mg/L, EC50 (daphnia, 48h): 0.29 mg/L
Persistence and Degradability: Biodegradable under aerobic conditions, breaks down in natural environments slowly
Bioaccumulative Potential: Low, log Kow indicates limited potential for bioaccumulation
Mobility in Soil: Moderate mobility, leaches through soil to groundwater, binds to some soil particles
Other Details: Avoid release to surface water and municipal sewer systems without proper treatment
Waste Handling: Treat as hazardous waste, landfilling or incineration should follow local, regional, national regulations
Contaminated Packaging: Empty containers may retain residues, all packaging should be cleaned or disposed of as hazardous waste
Disposal Methods: Collect in labeled, sealed containers for proper disposal, consult licensed hazardous waste disposal contractor
Do Not: Discard in household garbage, pour into drains, or allow to contaminate the environment
UN Number: UN 3077
Proper Shipping Name: Environmentally hazardous substance, solid, n.o.s. (Hydroquinone)
Transport Hazard Classes: 9 (Miscellaneous dangerous substances and articles)
Packing Group: III
Marine Pollutant: Yes
Special Transport Precautions: Avoid rough handling, do not transport with food, ensure containers are tightly sealed and upright, follow national and international regulations such as ADR, IMDG, IATA
GHS Classification: Covered by GHS for acute toxicity, eye and skin irritation
US Regulations: Listed in SARA 313, CERCLA (RCRA D code U197), TSCA inventory
EU Regulations: Included in REACH candidate list, classified under CLP Regulation (EC) No 1272/2008
Labeling Elements: Hazard pictograms, signal word, hazard and precautionary statements as per local legislation
Workplace Labeling: Comply with OSHA Hazard Communication Standard, GHS, and local laws for workplace chemical labeling
Canadian Regulations: WHMIS classification includes D1B (toxic material), D2B (other toxic effects)
