4
Sep
Reagent Bottles with Screw Caps vs Glass Stoppers: What to Choose?
Reagent bottles are essential for the safe storage of chemicals in laboratories. Available with either screw caps or glass stoppers, these bottles are usually made from BORO 3.3 borosilicate glass, offering durability, chemical resistance, and thermal stability. For Australian schools, universities, and industry labs, selecting the right closure type ensures both safety and efficiency.
Reagent Bottles with Screw Caps
Screw-cap reagent bottles are widely used for their practicality and secure sealing.
- Made with polypropylene screw caps or caps with PTFE liners.
- Provide excellent chemical resistance and airtight sealing.
- Easy to open and close, even with frequent use.
- Suitable for aqueous solutions, solvents, and general storage.
Screw caps are particularly valued in busy laboratories where speed and convenience are important.
Reagent Bottles with Glass Stoppers
Glass-stopper bottles represent a more traditional design but remain highly effective.
- Ground-glass stoppers create a tight, reusable seal.
- Excellent for long-term storage of chemicals where stability is critical.
- Withstand heating and flame-sealing applications.
- Favoured in analytical labs, pharmaceuticals, and teaching environments.
While they require careful handling and occasional greasing, glass stoppers provide a chemically inert closure solution.
Comparison Table: Screw Caps vs Glass Stoppers
| Feature | Screw Caps | Glass Stoppers |
|---|---|---|
| Material | Polypropylene or PTFE-lined | Ground borosilicate glass |
| Ease of Use | Quick to open and close | Requires careful handling |
| Seal Quality | Excellent, airtight | Excellent, reusable |
| Heat Resistance | Limited by cap material | Very high, suitable for heating/flame use |
| Best Applications | General lab storage, solvents, routine use | Long-term storage, analytical work, teaching |
| Sustainability | Plastic component, replaceable | Fully glass, long-lasting, reusable |
FAQs
Q1: Which closure is better for storing volatile solvents?
Screw caps with PTFE liners are preferred as they provide superior sealing and prevent evaporation.
Q2: Do glass stoppers require grease?
Some do, especially for long-term storage, to prevent sticking and ensure an airtight seal.
Q3: Can both screw-cap and glass-stopper bottles be autoclaved?
Yes, BORO 3.3 bottles are autoclave-safe, though plastic caps may degrade faster than glass stoppers.
Q4: Which is more sustainable?
Glass-stopper bottles are fully glass and long-lasting, while screw-cap bottles require eventual replacement of the plastic caps.
References
- ISO 4796: Laboratory Glassware — Bottles for Liquids.
- ASTM E438: Standard Specification for Glasses in Laboratory Use.
- ISO 3585: Borosilicate Glass 3.3 — Properties and Standards.
- University of Melbourne Chemistry Laboratory Safety Guide.
- NIST Chemistry WebBook, National Institute of Standards and Technology.
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