Sampling Methodology

A sampling methodology is a structured approach to estimating packaging weights when it is not practical to weigh every individual item. Under pEPR, sampling must be robust enough to produce accurate data for RPD reporting.

Good sampling practices include:

• Representative samples — samples should reflect the full range of packaging variants
• Sufficient sample size — enough items measured to be statistically reliable
• Regular updates — re-sample when packaging specifications change
• Documentation — record methodology, sample sizes, and results
• Consistency — use the same methodology across reporting periods

Sampling is commonly needed for: packaging with variable fill weights, packaging imported from multiple suppliers, and businesses with very large product ranges. The methodology should be documented and available for audit purposes. Regulators accept sampling as long as it is reasonable, well-documented, and produces results within an acceptable margin of error. Key packaging items by volume should be weighed precisely rather than sampled.