How Should Packaged-Goods Fill Quantity Be Controlled in Great Britain?

Packaged-goods quantity-control planning

Direct answer: A packaged-goods project in Great Britain should begin with the packer's chosen legal quantity-control method, the nominal quantity, product and package scope, suitable measurement equipment, sampling or every-pack checking plan, records and reject or correction process. The filling machine supplies product, but the packer remains responsible for the compliant quantity-control system. Obtain application-specific advice from Trading Standards where required.

This guide explains machinery-project inputs; it is not legal advice and does not replace the current regulations or the packer's own quality and metrology assessment. The official GOV.UK packaged-goods guidance should be used as the primary reference.

What is the difference between minimum and average quantity systems?

Under the minimum system, packages are made up so they contain at least the quantity shown. Under the average system, a controlled population may vary around the nominal quantity but must meet the applicable packer's rules. The buyer should confirm the selected system, sampling and limits with the responsible quality or legal-metrology adviser before machinery acceptance criteria are fixed.

GOV.UK explains the average-system rules and their scope, including the requirement that contents are not less on average than the nominal quantity, limits on packages below the tolerable negative error and the prohibition on a package being short by twice that error. Do not copy a generic limit into a URS without confirming the product, nominal quantity, jurisdiction and current official guidance.

Is the filling machine alone a packaged-goods quantity-control system?

No. A filler is one part of the process. Quantity control also depends on product condition, container or tare variation, measurement equipment, sampling, records, settings, operator response and the packer's defined compliance method. A highly repeatable dosing cycle can still produce an unsuitable legal or commercial result if the measurement and control plan are wrong.

Define whether the line checks samples offline, weighs every pack or uses another approved method. If a checkweigher or scale feeds back to the filler, specify the filtering, delay, limits, authority and response to a failed measurement. Feedback must not conceal individual nonconforming packs or create unstable repeated adjustments.

What measurement equipment and records are needed?

Measurement equipment must be suitable for the intended packaged-goods checks and used under a controlled procedure. The required approval, verification and record arrangements depend on how the equipment is used and the packer's system. GOV.UK advises businesses to consult Trading Standards on suitable equipment for their sector.

Record the equipment identity, check or calibration status as required by the quality system, product and format, sample times, results, adjustments, rejected or reworked packs and the person responsible. The official GOV.UK equipment and records guidance explains record duties for the average system and should be checked for current requirements.

How do tare, density and temperature affect the quantity result?

A net-weight result depends on the correct tare, while a volume-related result can depend on product temperature, density, aeration and the measurement method. Container mass variation, product retained on the pack or nozzle and foam settling can make a dosing problem appear better or worse than it is. Define conditioning and measurement consistently.

For gravimetric checks, use a tare strategy that reflects the actual packaging components and variation. For products sold by volume, confirm how the declared quantity is established and how temperature or entrained air is handled in the packer's procedure. Do not convert automatically between mass and volume using an assumed density.

What should be tested during FAT and SAT?

Test the agreed formats and products under stated conditions, using the defined measurement equipment and sample procedure. Capture the fill setting, product temperature, tare method, sample sequence, results, adjustments, reject function and response to a simulated adverse result. Separate machine repeatability evidence from the packer's compliance decision.