Physicochemical Properties

Alcohol (95%) is an aqueous ethanol solution containing approximately 95% ethanol by volume, representing the near-azeotropic composition of ethanol and water. It presents as a colorless, mobile liquid with a characteristic pleasant odor and a distinct burning taste upon contact. The reagent is highly volatile, with a low boiling point relative to many common laboratory solvents, which contributes to its rapid evaporation under ambient conditions.

A defining feature of Alcohol (95%) is its broad miscibility profile. It mixes freely with water, chloroform, diethyl ether, methanol, acetone, and the majority of other common organic solvents, making it an exceptionally versatile medium for dissolution, extraction, and reaction chemistry. This miscibility is attributable to the amphiphilic nature of the ethanol molecule, which bears both a polar hydroxyl group and a nonpolar ethyl chain.

Safety and Hazard Information

Alcohol (95%) is classified as a highly flammable liquid and must be handled with appropriate precautions in the laboratory. Its vapors are denser than air and can travel to ignition sources at a distance, accumulating in low-lying areas. Critically, the vapors are capable of forming explosive mixtures with air across a defined concentration range; therefore, work with this reagent must always be performed away from open flames, sparks, and other ignition sources.

Recommended personal protective equipment (PPE) includes chemical-resistant gloves, safety goggles or a face shield, and a laboratory coat. Operations involving significant volumes or prolonged exposure should be conducted in a well-ventilated fume hood. Containers must be kept tightly closed when not in use to minimize vapor release. In the event of a spill, eliminate all ignition sources immediately, ventilate the area, and absorb the liquid with inert, non-flammable absorbent material before disposal in accordance with local regulations.

First-aid measures: In case of skin contact, wash with copious amounts of water. If vapors are inhaled in quantity, move the affected person to fresh air and seek medical attention if symptoms persist. Always consult the current Safety Data Sheet (SDS) for this product before use.

Storage Requirements

Alcohol (95%) must be stored in a cool, dry, well-ventilated area, strictly away from heat sources, open flames, and direct sunlight. Storage should be in tightly sealed, approved flammable-liquid containers—ideally fabricated from compatible materials such as borosilicate glass or approved high-density polyethylene (HDPE). Metal safety cans with flame arrestors are recommended for bulk quantities.

The storage location should be designated as a flammable-materials storage zone, clearly labeled and equipped with appropriate fire-suppression resources. Alcohol (95%) should be segregated from strong oxidizing agents, peroxides, and strong acids, as contact with these substances can result in vigorous or hazardous reactions. Inventory should be managed on a first-in, first-out (FIFO) basis, and containers should be inspected regularly for integrity. Keep quantities stored in the laboratory workspace to the minimum needed for immediate use.

Laboratory Applications and Protocols

Alcohol (95%) finds broad application across multiple research disciplines. Its most common laboratory uses include:

• Solvent and Extraction Medium: Used to dissolve or extract organic compounds, natural products, and biological macromolecules. Its broad miscibility makes it suitable for liquid–liquid extraction and precipitation protocols.
• Sterilization and Disinfection: Widely employed to disinfect bench surfaces, laboratory equipment, and biological safety cabinets. Note that 70–75% ethanol is generally more effective for microbial inactivation than 95%; the 95% grade is often diluted before disinfection use.
• Nucleic Acid Precipitation: Ethanol precipitation is a standard method to concentrate and purify DNA, RNA, and oligonucleotides from aqueous solution, exploiting reduced solubility of nucleic acids in high-ethanol environments.
• Tissue Fixation and Histology: Used as a dehydrating agent in tissue processing protocols for light microscopy, typically as part of a graded ethanol series.
• Reaction Solvent: Serves as a solvent or co-solvent in various organic synthesis and analytical chemistry procedures owing to its low toxicity profile relative to many alternatives.

When preparing working solutions or dilutions, always add Alcohol (95%) to water (not water to alcohol) to control mixing heat, and verify final concentration using a calibrated densitometer or refractometer if precision is required.

Procurement and Quality Considerations

When procuring Alcohol (95%) for research use, researchers and lab managers should verify the purity grade and intended application. Aladdin Scientific offers Alcohol (95%) under SKU A112722. Prior to ordering, confirm that the specification meets the requirements of your specific protocol—for instance, whether trace water content, denaturant absence, or specific impurity limits are critical parameters for your assay.

For regulatory and institutional compliance, note that ethanol-containing reagents may be subject to local purchase controls, documentation requirements, or usage logs depending on jurisdiction. Ensure that your institution's chemical inventory management system is updated upon receipt of new stock. Review the current SDS and certificate of analysis (CoA) upon each new lot received to confirm the product meets your quality standards before use.