Most temperature problems are cheaper to prevent than to assess. Prevention starts with the right fridge, sited and loaded so air can move, and rooms kept within the range on the pack. The one thing to remember: the product label sets the range, and you need to show your fridge and your room actually hold it.
Why it matters
Why the box and the room matter
A fridge that cannot hold an even temperature produces excursions. SPS explains that medicines fridges use fan cooling and have no ice box or salad drawer, and the NHS Pharmaceutical QA Committee warns that parts of a domestic fridge can routinely drop below freezing (SPS). Freezing can irreversibly damage vaccines and biologicals.
Rooms are easier to forget. CQC expects care home policies to say how staff monitor the temperature of medicines storage areas, including residents' rooms (CQC), and the VMD says its inspectors now expect ambient records wherever medicines are kept (VMD blog).
What the rules say
Pharmaceutical fridge or domestic?
For vaccines the position is clear. The Green Book says vaccines must be stored in specialised pharmaceutical fridges and domestic fridges must not be used, and CQC's GP mythbuster 17 repeats it. For wholesalers, the MHRA Inspectorate blog says a pharmaceutical refrigerator is required.
For other medicines, SPS says domestic fridges are "not recommended" in healthcare settings, and laboratory fridges are unsuitable too. CQC's care home fridge guidance agrees, with one narrow exception: a small service that rarely holds fridge items could use a locked container in the food fridge, with full monitoring and a risk assessment. In supported living, CQC expects medicines to stay in people's own homes (CQC).
| Control | Green Book | MHRA blog | NHS SPS | CQC care homes | WHO |
|---|---|---|---|---|---|
| Expects a pharmaceutical or dedicated medicines fridge | ✓ | ✓ | ✓ | ✓ | ✓ |
| Rules a domestic fridge out | ✓ | ✓ | · | · | · |
| Allows a narrow exception | · | · | · | ✓ | ✓ |
| Warns a 'medical' label is no guarantee | · | ✓ | · | ✓ | · |
A filled cell means the source says it. The Green Book covers vaccines, the MHRA blog wholesale storage, and WHO accepts household-style units only if independently tested against a pharmaceutical refrigerator standard.
What a medicines fridge should be
The NHS Pharmaceutical QA Committee's model specification makes a good buying checklist: cleanable materials, no freezer box, salad drawer or door shelves, automatic defrost, grille shelving, an internal fan and a lock. The MHRA blog adds a calibrated min/max thermometer accurate to ±0.5 °C, readable without opening the door, and checking how the unit copes with power cuts and hot spells.
For freezers, the MHRA's freezer blog says fridge ice boxes are "not supported in any circumstance" for GDP use and warns that domestic auto-defrost cycles can cause high excursions.
What good looks like
Placing and loading the fridge
SPS recommends a 5 °C set point, clearance on all sides away from heat, feet levelled so the door swings shut, and protection against switch-off (see Power failures and contingency). The Green Book adds a ventilated site, a unique identifier and at least yearly servicing, with servicing, defrosting, cleaning, calibration and PAT testing logged beside the fridge.
Loading is about air. SPS says not to overfill, to keep stock off the walls and base, and to use mesh baskets rather than solid trays. The Green Book warns that vaccines against the back wall may freeze, and UKHSA's poster says to keep them in original packaging, shortest-dated at the front. No food, drink or specimens, and the RPS says lock the fridge when not in use.
The MHRA blog puts the probe centrally, not in the door; EU GDP and WHO put it where mapping shows the extremes; SPS suggests an air sensor plus a load sensor. See Mapping and qualification and Monitoring, alarms and calibration.
Rooms, cupboards and the 25 °C question
SPS says that ideally all medicines storage areas would be held between 15 °C and 25 °C, with air conditioning where possible and ambient cabinets for small quantities where not (SPS). UKHSA's hot weather guidance says "most medicines should be kept below 25°C". Neither replaces the pack: ambient ranges run from 8 °C to 30 °C, and storing outside them takes a medicine outside its licence.
Watch the bottom of the range too: the VMD recommends avoiding ambient storage below 12 °C because of condensation. Products with no storage statement still need monitoring, says the EMA GDP Q&A.
SPS treats a min/max recorder as the minimum in storage locations, and the 2015 QA Committee document asks for daily readings in the worst-case spot. That was written for NHS wards; care homes and GP practices usually adopt it by analogy.
In a heatwave
If a room goes over, it is an excursion. SPS says a single, isolated excursion of less than 5 °C above the labelled maximum, lasting under seven days, is unlikely to harm medicines. It does not cover rooms that run hot every summer, or relax wholesale requirements. The assessment is on Temperature excursions. SPS's hot weather measures:
- Keep stock to a minimum, with strict rotation.
- Move medicines out of direct sun; consider reflective window film.
- Keep windows and doors shut unless it is cooler outside.
- Do not move ambient medicines into the fridge unless the label allows it.
- Remind patients not to leave inhalers in parked cars (SPS on heatwaves).
Worked example
An illustrative July afternoon
This is an illustrative example in a care home. Wednesday 15:00 in a July heatwave, the medicines room min/max reads 26.8 °C now, 27.5 °C maximum; yesterday's maximum was 26.9 °C. Most stock is labelled "do not store above 25 °C".
The senior carer records both readings and escalates to the supplying pharmacist. One event, under 5 °C over, two days so far: inside SPS's single-excursion rule. They draw the blinds, move the trolley off the sunny wall and confirm the fridge has stayed below 8 °C. The decision and the pharmacist's name go on the record.
In September the manager notes the room has passed 25 °C two summers running, so it is no longer isolated, and the risk assessment now plans an ambient cabinet or cooling.
Where it is unclear
Where the sources disagree
Domestic fridges get three answers: never for vaccines, not recommended otherwise, and acceptable to WHO only if independently tested (domestic fridges). Probe placement depends on whether you follow the MHRA default or your mapping (centre or extremes?).
For rooms, UKHSA's 25 °C rule, SPS's single-excursion tolerance and the 2015 QA Committee's stricter trigger (more than 5 °C over, or more than a day) sit side by side (25 °C ceiling or a tolerance?). For rooms that spike every afternoon, SPS describes mean kinetic temperature, which the MHRA Inspectorate discourages in wholesale (MKT).
Inspection findings
What inspectors have found
The MHRA's 2016 GDP deficiency data cited a walk-in fridge with dirt around the fans and no cleaning schedule. Its 2016 GMP data includes a fridge checked only weekly with no max/min readout and a receiving area not monitored against its limit. VMD inspectors can seize products whose storage may have compromised them.
In summary
The short version
- Use a pharmaceutical or dedicated medicines fridge, and never a domestic fridge for vaccines.
- Check the unit holds +2 °C to +8 °C in your room, at your load.
- Site it with clearance, away from heat, levelled and protected from switch-off.
- Load for airflow: off the walls and base, original packaging, nothing but medicines.
- Log servicing, cleaning, defrosting, calibration and PAT testing beside the fridge.
- Monitor rooms as well as fridges, against each product's label.
- Plan for hot weather, and fix a room that runs hot every summer.