Carboy, Plastic

Quick Answer: A plastic carboy is a large laboratory container, usually moulded in polyethylene or polypropylene, used to store, carry and dispense bulk liquids such as distilled water, buffers, dilute reagents and collected aqueous waste.

Where a Plastic Carboy Fits Among Lab Containers

The Carboy, Plastic is the container a lab turns to when the volume outgrows ordinary reagent bottles. It holds the day’s or week’s supply of distilled or deionised water, a large batch of buffer, or aqueous rinse waste waiting for neutralisation. Carboys generally have a screw closure and carrying handles, and many are also offered with a tap near the base so liquid can be drawn off without lifting and tipping a heavy vessel.

A carboy and a narrow mouth bottle do different jobs. The bottle is poured by hand at the bench; the carboy is heavy when full, so it normally stays in one place, is filled at the top and emptied through a tap or by siphon. Many labs keep one carboy as the reservoir and decant from it into bench bottles and wash bottles.

The polymer decides what a carboy can hold. Polyethylene (HDPE or LDPE) is tough and generally resists aqueous acids, alkalis and salt solutions; polypropylene has similar chemical resistance and is generally the grade chosen when a carboy must be autoclaved. The title of this listing says only “plastic”, so check which polymer it is before storing solvents or putting it through an autoclave.

Specifications

Care & Handling

• Label every carboy with its contents and date, and never reuse a waste carboy for water or reagents.
• Store it out of direct sunlight: UV light slowly degrades polyethylene and polypropylene and encourages algae in stored water.
• Lift a full carboy with both hands by its handles or move it on a trolley; never carry it by the cap or neck.
• If a tap is fitted, check it and its washer for drips before leaving the carboy full overnight.

Applications

• Reservoir of distilled or deionised water for filling wash bottles and bench bottles.
• Making up and holding large batches of dilute salt or buffer solutions for class practicals.
• Collecting aqueous waste for neutralisation or disposal, clearly labelled and kept separate from water carboys.
• Carrying water samples or process liquids between a field site and the lab.

Why Choose LabEquip

Carboys like this one are ordered mainly by labs that use water or buffer in volume: school chemistry departments, water-testing labs and microbiology teaching labs. LabEquip can supply the carboy together with smaller narrow mouth plastic bottles for bench use; the Lab Glassware category lists other containers, and you can send your capacity requirement to our team.

Frequently Asked Questions

What is the difference between a carboy and a large reagent bottle?

A carboy is designed for bulk volumes and usually stays in one place as a reservoir, often with handles and sometimes a bottom tap. A reagent bottle is smaller and poured by hand at the bench. Labs typically fill bench bottles and wash bottles from the carboy.

Can a plastic carboy be autoclaved?

It depends on the polymer. Polypropylene carboys are generally autoclavable, while polyethylene softens at autoclave temperatures and usually is not. Check the rating of this carboy first, and always loosen the cap during the cycle.

Is a plastic carboy suitable for distilled or deionised water?

Yes, this is one of its most common uses. Keep it closed to limit dust and carbon dioxide uptake, store it away from sunlight to discourage algae, and periodically empty, rinse and refill it rather than topping up indefinitely.

Can organic solvents be kept in the carboy?

Only with care. Polyethylene and polypropylene resist alcohols and many aqueous chemicals, but aromatic and chlorinated solvents such as toluene, xylene and chloroform can swell or permeate them. Keep those in containers rated for solvents.

How do I clean the inside of a carboy?

Wash it with warm water and a mild laboratory detergent, using a long-handled brush to reach the shoulders and base. Rinse several times with tap water, finish with distilled water, and drain it inverted with the cap off.

Is it safe to lift a full carboy?

Water weighs about one kilogram per litre, so even a moderate-sized carboy is heavy when full. Keep it on a low, stable shelf or on the floor near where it is used, and move it with a trolley or two people when full.

Last Updated: September 2026