UKAS accredited calibration laboratory No. 10723

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For anyone responsible for temperature-controlled storage

What to do when storage goes out of range

When a fridge, freezer or store goes out of range, first protect the stock: keep it in the right conditions, quarantine it and record the time. Then assess whether it's still usable from how warm or cold it got and for how long, against the manufacturer's stability data, find the cause, fix it so it doesn't happen again, and record each step with a named decision on the stock.

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Updated 18 October 2026Reviewed by Jake Farrow, Managing Director

At a glance

What it asks

The incident, start to finish

From alarm to closed, with a record at every step

Sematics records an incident through six stages, so an inspector can see who did what and when, from the first alarm to the preventive action.

The incident lifecycle, as Sematics records it
  1. OpenedAlarm raised, start time logged
  2. AcknowledgedA named person responds
  3. Root causeWhy it happened
  4. Corrective actionFixed, stock assessed
  5. Preventive actionSo it doesn't recur
  6. ClosedReviewed and signed off
An excursion on the recordIllustrative
Medicines fridgelimits 2 to 8 °C

Door left ajar at 18:20: alarm acknowledged at 18:31, door closed, back in range by 18:52. Start, peak and duration recorded for the stock decision.

An illustrative trace. The start time, peak and duration are what the stock decision depends on.

Green Book ch. 3, GDP 9.2

1. Contain: protect the stock first

What it says

The Green Book's steps for a fridge failure start with keeping the door closed until the situation has been assessed, then quarantining affected stock separately while keeping it in the cold chain, clearly labelled, and recording all details. GDP 9.2 expects excursions in transit to be reported to the distributor and the recipient, and a procedure for investigating and handling them.

What it means on site

The instinct is to open the fridge to check, or to bin the stock. Both can make things worse: opening lets more warm air in, and discarding destroys the evidence and possibly usable stock. Quarantine, label, and keep it cold.

How to evidence it

  • A written excursion procedure that staff can find at 2am
  • Back-up storage arrangements
  • Quarantine labels and a record of where the stock went

SPC, ICH Q1A(R2), UKHSA vaccine incident guidance

2. Assess: how warm, how long, and is it still good

What it says

Establish the last reliable reading, when the excursion started, its peak and its duration. Compare that with the product's labelled storage conditions and the manufacturer's stability data (in the SPC, or from their medical information team). For medicines stored over time, mean kinetic temperature (MKT), defined in ICH Q1A(R2), combines a series of readings into a single temperature that reflects their overall effect; it helps assess the impact of fluctuations over a period, alongside the stability data. It isn't a way to average away a short, sharp excursion. UKHSA's vaccine incident guidance notes that a one-off rise above +8 °C lasting under 20 minutes, with vaccines in their original packaging and stored properly before, is unlikely to breach the cold chain. That is NHS clinical guidance and doesn't apply to WDA or MIA holders: under GDP and GMP every excursion is a deviation.

What it means on site

Everything here depends on the start time. A min/max thermometer read the next morning gives the peak but not when or how long, and without that the manufacturer usually can't advise and stock that was fine may be destroyed.

How to evidence it

  • The readings for the period: start, peak, duration and return to range
  • The stability data or manufacturer's advice used, with a reference
  • MKT calculation, where used, and the readings behind it

GDP 1.2

3. Investigate: find the real cause

What it says

GDP 1.2 expects the quality system to make sure deviations from established procedures are documented and investigated. For an excursion, that means working out why it happened: equipment failure, a defrost cycle, a door left open, a power cut, overloading, a process step missed, or a sensor that has drifted or moved.

What it means on site

'Door left open' is often recorded as the cause when it's really the symptom. Why was it left open, and why did nobody notice for an hour? The answer to that is where the preventive action comes from.

How to evidence it

  • The investigation record and the root cause identified
  • Supporting evidence: service reports, door or power logs, staff statements

GDP 1.2, ISO 15189 8.7

4. Correct and prevent: CAPA

What it says

GDP asks for appropriate corrective and preventive actions (CAPA) to correct deviations and prevent them, in line with quality risk management. ISO 15189 8.7 expects a laboratory to control and correct a nonconformity, deal with its consequences, investigate the cause and take corrective action proportionate to its effect. Corrective action fixes this incident; preventive action stops the next one.

What it means on site

The corrective action is usually done on the night. The preventive action, such as a door alarm, a service, moving the alarm limits or retraining, is the bit that gets forgotten, and the same unit alarms again a month later.

How to evidence it

  • The corrective action taken, and when
  • The preventive action, who owns it and when it was completed
  • A check that it worked: no repeat on the same unit

GDP chapter 2

5. Decide and record: the named sign-off

What it says

A responsible person (the Responsible Person under GDP, the named vaccine leads under the Green Book, or a quality manager) reviews the incident and decides on the stock: release, use with conditions, return or destroy. The decision and its reasoning are recorded with the rest of the incident and kept for as long as your rules require.

What it means on site

An inspector will pick one excursion and ask you to walk through it. If the readings, the response, the cause, the actions and the stock decision are in different places, that walk-through gets long.

How to evidence it

  • One incident record holding readings, alarm, response, cause, actions and decision
  • The decision on the stock, signed and dated by a named person
  • Trend review across incidents: repeat units, times and causes

In the inspector's words

Questions to be ready for

The kind of questions an inspector, assessor or auditor puts. If you can answer each with a record, you're ready.

  1. “Talk me through your last temperature excursion, from the alarm to the decision.”
  2. “When did it start, how warm did it get, and for how long?”
  3. “Who decided the stock could be used, and on what evidence?”
  4. “What was the root cause, and what did you change so it doesn't recur?”
  5. “Has this unit alarmed before?”
  6. “Where is your excursion procedure, and does the night shift know it?”

Where JTF fits

Where JTF fits

Sematics, our monitoring platform, opens an incident when an alarm fires and records each stage: who acknowledged it and when, the root cause, the corrective and preventive actions, and the sign-off, alongside the readings that show the start, peak and duration. Alarms reach a person out of hours, so the response starts at the excursion, not the next morning. Across Sematics in 2026, 93% of closed incidents carried the full record where it was required: acknowledgement, root cause, corrective and preventive action.

Checklist

MHRA GDP and Green Book temperature checklist

Storage, alarms and excursion records for medicines and vaccines, on one A4 sheet.

Download the checklist

Related

Keep reading

Questions

Common questions

What counts as a temperature excursion?

Any time storage goes outside its defined range, such as the labelled conditions for a medicine or the limit in your HACCP. How significant it is depends on how far out and for how long.

Can we use stock after an excursion?

Sometimes. Keep it quarantined in the right conditions and get the manufacturer's stability data or advice. A named person decides and records the decision; for vaccines, the Green Book makes that the user's responsibility, case by case.

What is mean kinetic temperature, and should we use it?

MKT is a single temperature that reflects the combined effect of fluctuating temperatures on a medicine's stability over time (ICH Q1A(R2)). It can help assess storage over a period, with the stability data. It shouldn't be used to hide a short excursion.

How long should we keep excursion records?

As long as your rules require: at least five years for GDP records, at least a year and the full storage history of the stock for vaccine fridges under the Green Book, and the retention period you define under ISO 15189 (the standard sets no number; RCPath supplies the periods) or BRCGS.

Who should get the alarm?

Someone who can act on it at the time, with cover out of hours and an escalation if they don't respond. An alarm that only sounds in an empty room isn't a control.

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Sources

  1. EU Guidelines on Good Distribution Practice of medicinal products for human use (2013/C 343/01), applied in Great Britain by the MHRA
  2. MHRA: Good manufacturing practice and good distribution practice (GOV.UK)
  3. UKHSA, The Green Book, chapter 3: Storage, distribution and disposal of vaccines
  4. UKHSA: Vaccine incident guidance, responding to vaccine errors (includes cold chain breaches)
  5. ICH Q1A(R2) Stability testing of new drug substances and drug products (EMA scientific guideline; defines mean kinetic temperature)
  6. ISO 15189:2022 Medical laboratories: requirements for quality and competence

This summary isn't official guidance. The source documents are what an inspector works from.

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