Dimethyl sulfoxide (DMSO) is a powerful polar aprotic solvent with a wide range of applications in pharmaceuticals, chemical synthesis, and biological research. While DMSO is stable under normal conditions, it requires proper storage to maintain its quality and ensure safe handling. Below are key storage precautions to consider when working with DMSO.

1. Temperature Control

• Store at room temperature (typically 15–25°C / 59–77°F).
• Avoid high heat, as DMSO has a relatively low flash point (about 87°C / 189°F).
• In cold environments (below ~18°C or 64°F), DMSO may crystallize or freeze into a solid. This is normal and does not affect its quality. Simply warm it gently (e.g., in a warm water bath) to re-liquefy.

2. Keep the Container Tightly Sealed

• DMSO is hygroscopic, meaning it absorbs moisture from the air. This can dilute the DMSO and affect its performance, especially in sensitive chemical or biological applications.
• Use airtight containers to minimize moisture absorption and contamination.
• Avoid frequent opening and closing of the container.

3. Use Appropriate Containers

• Store DMSO in glass, high-quality plastic (like HDPE), or stainless steel containers.
• Avoid using low-grade plastics or rubber materials, as DMSO can dissolve certain plastics and cause leaks or contamination.

4. Label Clearly

• Ensure containers are clearly labeled with: Chemical name: Dimethyl Sulfoxide (DMSO) Concentration (if mixed) Hazard symbols (flammable, irritant) Date of receipt or opening (for quality tracking)

5. Ventilation and Fire Safety

• Store in a well-ventilated area to prevent vapor accumulation.
• Keep away from ignition sources, as DMSO is combustible.
• Do not store near strong oxidizing agents (e.g., nitric acid, chlorine compounds), as these may react with DMSO under certain conditions.

6. Avoid Cross-Contamination

• Use clean tools and dispensing equipment to prevent introducing impurities.
• In research and medical applications, even minor contamination can interfere with results.

7. Personal Safety Precautions

• Wear appropriate protective equipment when handling DMSO, including gloves, goggles, and lab coats.
• DMSO is known for its ability to penetrate skin and carry other chemicals with it, so gloves should be chemical-resistant (nitrile recommended).
• Avoid skin contact, as DMSO may cause irritation or systemic exposure.

8. Disposal

• Dispose of DMSO according to local environmental regulations.
• Do not pour large quantities down the drain without proper dilution and approval.

Conclusion

While DMSO is a useful and generally stable chemical, improper storage can lead to safety hazards, reduced effectiveness, and environmental risks. By following these storage guidelines, users can ensure the safe, efficient, and long-lasting use of this versatile solvent in labs, industry, or medical settings.