SOP on Disposal of Left-Over Test Samples (Example)

In short: This example SOP describes how a QC laboratory can decide when left-over test samples may be discarded, how to segregate them, and how to document disposal without mixing samples or leaking product information. It does not give chemical treatment recipes: the disposal route for each material must come from its safety data sheet and your site’s EHS and hazardous-waste procedures.

This is an illustrative template to be adapted under your own quality system. Values marked “example in-house criterion” are site practices, not regulatory requirements.

1. Objective

To lay down a procedure for disposal of left-over test samples after analysis.

2. Scope

This example SOP applies to left-over test samples of raw materials, in-process samples and finished products in the Quality Control laboratory of a pharmaceutical manufacturing facility. It is intended to prevent mix-up and cross-contamination with other samples.

It does not cover reserve (retention) samples, which are kept for the periods set by GMP and are handled under a separate procedure (see section 4).

3. Responsibility

• Analyst / section head or designee: confirms release conditions, segregates the samples and records disposal.
• Head of Quality Control / Quality Assurance or designee: ensures the SOP is implemented and checks records periodically.
• EHS / waste management: accepts segregated waste and decides the disposal route.

4. Samples that must not be discarded

• Reserve and retention samples. These are separate from left-over test samples. EU GMP Annex 19 (3.1) requires reference and retention samples of each finished-product batch to be kept for at least one year after expiry, and 21 CFR 211.170 sets reserve-sample retention periods for active ingredients and drug products (generally 1 year after expiry for drug products). Do not treat them as left-over material.
• Samples under investigation. Keep the remaining sample (and any solutions) when an out-of-specification, out-of-trend or deviation investigation is open, until QA closes it.
• Samples needed for re-test or ongoing stability. Keep the quantity required by the approved protocol or specification.

5. Procedure

5.1 When disposal is allowed

Dispose of a left-over test sample only after:

1. analysis is complete and results are reviewed and approved in the analytical record;
2. there is no open investigation, re-test request or complaint linked to the sample; and
3. the retention period set by the site for test remnants has passed. Example in-house criterion: the day after QC approval of the batch result, or as defined in your own SOP.

5.2 Identify the hazard first

Before handling, check the safety data sheet (SDS) and the sample label for hazard class (for example toxic, corrosive, flammable, potent, cytotoxic, hormonal, antibiotic or sensitising). Wear the PPE the SDS and your safety SOP require.

5.3 Segregate

Segregate left-over material by type and hazard into the labelled waste containers defined by your EHS / hazardous-waste procedure. Typical categories are:

• solid materials (raw materials, in-process powders and granules);
• liquid samples, which are not mixed with each other unless the waste procedure allows it;
• finished dosage forms (tablets, capsules, powders, liquids) removed from their primary packs;
• empty containers, labels and packaging.

Do not mix incompatible materials. Do not pour, wash or dilute any sample down a drain or into an effluent system unless your EHS procedure and the SDS for that material explicitly permit it. Potent, hazardous or regulated waste is handed over to the designated waste handler as per the hazardous-waste procedure and applicable local rules. See also the SOP on disposal of toxic waste materials.

5.4 Protect product and batch identity

• Deface or remove labels on sample containers and bottles so that product name, batch number and company details cannot be read, then send them as scrap or waste as per the site procedure.
• Tear or deface printed primary and secondary packing material so it cannot be reused.

5.5 Record

Record in the disposal log: date, sample name or code, batch or analytical reference number, quantity or container count, waste category, disposal route, and the signatures of the person who disposed of it and the person who verified it.

6. Records

Disposal logs and the related analytical records must be kept for at least 1 year after the expiry date of the respective product batch (EU GMP Part I, Chapter 4, section 4.11; 21 CFR 211.180(a)), and longer if local law or the marketing authorisation requires. See records maintenance in the QC laboratory.

7. Frequently asked questions

Is a left-over sample the same as a reserve sample?

No. A left-over sample is the remainder of a test portion after analysis. A reserve or retention sample is set aside deliberately under GMP for a defined period and must not be discarded early.

Can I wash liquid samples down the drain with water?

Only if the SDS and your site’s EHS procedure state that the specific material may be discharged. Otherwise, collect it as waste. This example SOP deliberately gives no chemical neutralisation or dilution steps.

Why deface the labels?

To avoid product or batch information leaving the laboratory and to prevent discarded containers from being reused.

8. Training and distribution

Training as per the employee training SOP. Distribution as per the SOP on SOPs. Annexure: none.

See also the general safety rules of the QC laboratory.

References

• European Commission, EudraLex Volume 4, Annex 19: Reference and Retention Samples, section 3.1 (revision C(2026) 4135 of 23 June 2026, applicable from 24 September 2026; replaces the 2005 version).
• US FDA, 21 CFR 211.170 (Reserve samples) and 211.56(a) (sanitation: trash and organic waste held and disposed of in a timely and sanitary manner), current eCFR. https://www.ecfr.gov
• US FDA, 21 CFR 211.180(a) and EU GMP Part I Chapter 4, section 4.11 (record retention).