Product Name: Cresol Red
Chemical Name: o-Cresolsulfonephthalein
Synonyms: C.I. 73320, Metacresolsulfonphthalein
CAS Number: 1733-12-6
Recommended Uses: Laboratory reagent, pH indicator
Manufacturer: Laboratory chemical suppliers
Emergency Contact: Refer to local poison control center
Address: Available from product supplier or distributor
Classification: Not classified as hazardous under GHS criteria
Signal Word: Warning
Hazard Statements: May cause skin and eye irritation, possible respiratory tract irritation if inhaled, potentially harmful if swallowed
Precautionary Statements: Avoid contact with skin and eyes, avoid inhalation, use protective clothing
GHS Pictograms: Exclamation mark
Other Hazards: Dust may cause irritation, not classified as carcinogenic by ACGIH, IARC, NTP, or OSHA
Cresol Red: 98–100%
Chemical Formula: C21H18O5S
Impurities: Minor residual manufacturing byproducts may be present at trace levels
Ingredient Disclosure Threshold: All components are listed
Other Constituents: None known of regulatory concern
Inhalation: Move person to fresh air, keep at rest, seek medical attention if symptoms develop
Skin Contact: Wash with soap and water, remove contaminated clothing, seek medical advice if irritation develops
Eye Contact: Rinse cautiously with water for several minutes, remove contact lenses if present, call physician if symptoms remain
Ingestion: Rinse mouth, do not induce vomiting unless directed by medical personnel, get medical attention if feeling unwell
Most Important Symptoms and Effects: May cause mild to moderate irritation, prolonged exposure may worsen effects
Special Advice to Physician: Treat symptomatically
Suitable Extinguishing Media: Dry chemical, CO2, foam, water spray
Unsuitable Media: Direct water jet may spread material
Specific Hazards: Material decomposes to produce hazardous fumes under fire conditions including sulfur oxides, carbon oxides
Special Protective Actions for Firefighters: Wear self-contained breathing apparatus and protective gear
Explosion Data: Dust may develop combustible mixtures with air; avoid dust accumulation
Hazardous Combustion Products: Carbon monoxide, carbon dioxide, sulfur oxides
Firefighting Instructions: Move containers away from fire if safely possible; keep out unnecessary personnel
Personal Precautions: Wear appropriate protective equipment including gloves, goggles, and dust mask
Environmental Precautions: Prevent release into drains, sewers, waterways
Methods for Cleanup: Sweep or vacuum without raising dust, place into closed containers for disposal
Decontamination: Wash spill site with water after material pickup
Precaution for Other Persons: Restrict access to area until cleanup is complete
Waste Disposal: Dispose in accordance with local regulations
Reference to Other Sections: Wear exposure control measures as indicated
Precautions for Safe Handling: Use only in well-ventilated areas, avoid inhalation and contact with skin and eyes, handle with care to avoid spills
Avoidance of Incompatible Conditions: Do not handle near sources of ignition, heat, or oxidizing materials
Safe Storage Conditions: Store tightly closed in a cool, dry, well-ventilated area, protect from moisture and light
Packing Materials: Store in chemically compatible containers
Specific End Use Recommendations: Laboratory and industrial use only; avoid food or medical applications
Storage Temperature: Room temperature
Handling Practices: Avoid dust formation, ensure containers are labeled and sealed
Engineering Controls: Use with adequate ventilation, local exhaust preferred
Eye Protection: Chemical safety goggles or face shield
Skin Protection: Suitable gloves (nitrile or rubber), lab coat or apron
Respiratory Protection: Dust mask or NIOSH-approved respirator if ventilation is inadequate
Exposure Limits: No specific limits established for cresol red
Environmental Controls: Prevent spillage or leakage into the environment
Hygiene Measures: Wash hands after handling; do not eat, drink, or smoke while using
Physical State: Solid powder
Color: Reddish violet
Odor: Odorless or faint characteristic
Molecular Weight: 366.43 g/mol
Melting Point: 279–283°C
Boiling Point: Not applicable (decomposes on heating)
Solubility: Slightly soluble in water, soluble in alcohol
pH: pH indicator range 7.2 (yellow) to 8.8 (red-purple)
Vapor Pressure: Not available
Density: Approximately 1.4 g/cm³
Partition Coefficient: Not available
Auto-Ignition Temperature: Not determined
Explosive Properties: Dust explosion risk possible in air
Viscosity: Not relevant for solid
Chemical Stability: Stable under normal storage and handling conditions
Reactivity: Not reactive under normal conditions
Possibility of Hazardous Reactions: No dangerous polymerization expected
Conditions to Avoid: Excess heat, sources of ignition, strong acids or bases, oxidizers
Incompatible Materials: Strong oxidizing agents, strong acids
Hazardous Decomposition Products: Carbon monoxide, carbon dioxide, sulfur oxides on combustion
Storage Life: Stable for several years when stored properly
Routes of Exposure: Inhalation, ingestion, skin and eye contact
Acute Toxicity: Low toxicity expected from short-term exposure
Skin Corrosion/Irritation: May cause mild irritation with prolonged or repeated exposure
Serious Eye Damage/Irritation: Can cause temporary redness, watering, discomfort
Respiratory Sensitization: Dust may cause irritation, no allergic sensitization expected
Carcinogenicity: Not identified as a carcinogen by IARC, OSHA, NTP
Reproductive Toxicity: Data unavailable
Target Organ Effects: No target organ toxicity documented
Chronic Effects: Long-term exposure data unavailable, repeated exposure may amplify mucous membrane or skin irritation
Ecotoxicity: Product has not been tested as a whole; similar dyes show low aquatic toxicity at typical concentrations
Persistence and Degradability: Not readily biodegradable
Bioaccumulative Potential: Low expected based on structure
Mobility in Soil: Information not available; moderate mobility possible
Other Adverse Effects: Not classified as environmentally hazardous
Precautions: Avoid uncontrolled environmental release, prevent access to waterways and drains
Waste Disposal Methods: Dispose of through a licensed chemical waste contractor
Contaminated Packaging: Dispose as hazardous waste following local, regional, and national guidelines
Special Precautions: Do not release waste into sewers, ground, or water bodies
Waste Code: Consult local regulations
Measures: Collection in sealed, labeled containers for transfer to approved disposal site
UN Number: Not regulated for transport
Proper Shipping Name: Not classed as dangerous goods
Transport Hazard Class: None
Packing Group: None
Environmental Hazards: Not a marine pollutant
Transport in Bulk: Not applicable
Special Precautions: Protect from moisture and extreme temperatures during transport
US TSCA Status: Listed on the Toxic Substances Control Act inventory
EU REACH: Not subject to registration; complies with Annex IV or V
DSL/NDSL (Canada): Listed
SARA Title III (Sections 311, 312): Not regulated
California Prop 65: No ingredients listed
OSHA Status: Not regulated as hazardous
Other Regulations: All major chemical inventories worldwide
