Narrow Mouth Bottle, Plastic

Quick Answer: A narrow mouth plastic bottle is a screw-capped laboratory bottle with a small neck opening, typically moulded in polyethylene or polypropylene, used to store and pour liquid reagents, buffers, standards and water samples.

Narrow Mouth vs Wide Mouth: Which Bottle for Which Job

A narrow neck is the standard shape for liquids. The small opening pours in a controlled stream with less dribbling down the side, exposes less of the contents to air while the bottle is open, and takes a smaller cap that is easy to close tightly. That makes the Narrow Mouth Bottle, Plastic the everyday container for made-up solutions: dilute acids and alkalis, buffers, indicator solutions, standards and distilled water.

A wide mouth bottle is chosen instead for powders, pastes and solids that have to be spooned in and out, and it is easier to scrub inside. For bulk volumes that are too heavy to pour by hand, a carboy serves as the reservoir and narrow mouth bottles are filled from it for bench use.

Laboratory narrow mouth bottles are usually HDPE, LDPE or PP. Polyethylene is tough and generally resists aqueous acids, alkalis and salts; polypropylene offers similar resistance and is generally the one that can be autoclaved. Plastic is also preferred to glass for strong alkali solutions, which slowly attack glass and can seize a glass stopper, and for hydrofluoric acid, which etches glass.

Specifications

Applications

• Storing sodium hydroxide and other alkali solutions used in titration practicals.
• Holding prepared buffers and indicator solutions at student benches.
• Collecting and transporting water samples for chemical testing.
• Supplying distilled water or dilute reagents in class practical sets.

Care & Handling

• Label each bottle with its contents, concentration and preparation date.
• Leave headspace below the neck; liquids expand as they warm and a brim-full bottle can leak at the cap.
• Dedicate a bottle to one solution where possible, since plastics can hold traces of earlier contents.
• Store bottles away from direct sunlight and heat sources.

Why Choose LabEquip

Chemistry departments and water-testing labs buy narrow mouth plastic bottles in sets to equip reagent shelves and student practical trays. For solids, compare the wide mouth square plastic bottle; for solvents that are better kept in glass, see the narrow mouth reagent bottles in glass. Browse the Lab Glassware range or ask LabEquip for a quote.

Frequently Asked Questions

When should I use a narrow mouth bottle instead of a wide mouth bottle?

Use a narrow mouth bottle for liquids you pour, because the small neck gives a controlled stream and a tight seal. Use a wide mouth bottle for powders, solids and thick materials that must be scooped out, or when the inside needs thorough cleaning.

Is a plastic bottle suitable for sodium hydroxide solution?

Yes. Polyethylene and polypropylene generally resist alkali solutions, which is why sodium hydroxide and potassium hydroxide solutions are commonly kept in plastic. Strong alkali slowly attacks glass and can make glass stoppers stick.

Can the narrow mouth bottle be autoclaved?

That depends on the polymer. Polypropylene bottles are generally autoclavable, while polyethylene softens at autoclave temperatures. Check this bottle’s rating first, and loosen the cap during autoclaving so pressure can equalise.

Which chemicals should not be stored in it?

Avoid long-term storage of aromatic and chlorinated solvents such as benzene, toluene and chloroform, and strong oxidisers such as concentrated nitric acid, which can attack or permeate polyolefin plastics. Use glass or a container rated for those chemicals.

How should the bottle be cleaned before reuse?

Empty it, wash with a mild laboratory detergent and a bottle brush, rinse several times with tap water, then finish with distilled or deionised water. Drain it upside down and let it dry fully before capping.

Does a plastic bottle affect trace analysis?

It can in either direction. Plastic avoids the sodium, boron and silicate that glass can release, which helps for those determinations, but some plastics adsorb trace metals or leach additives. Clean the bottle with dilute acid and rinse with high-purity water before trace work.

Last Updated: September 2026