Martin Westover, Director at Signatrol, the temperature data logging experts, looks at the importance of continuous independent temperature monitoring for laboratory refrigeration.

The temperature conditions within all pharmaceutical fridges must be monitored on a regular basis to ensure that vaccines are maintained within their recommended limits and an inviolate record maintained. Many facilities still rely on manual temperature checks once or twice daily. While this approach may meet minimum requirements, it introduces several risks including missed readings due to staff absence or oversight, delayed awareness of temperature excursions, and incomplete or illegible records. Manual temperature checks can also mean that any issues detected overnight or at the weekend can potentially be missed.

A far more effective solution, in terms of labour, time cost and to avoid errors, is to introduce continuous monitoring using an independent alarmed data logger. Signatrol’s Cadmus series, independent of the fridge’s internal control, provides an accurate, impartial and inviolate record of actual storage conditions.

Cadmus takes a reading every minute, irrespective of sample store rate and if an alarm condition is detected, the email alert is sent immediately. Easily downloadable and secure electronic records, including historical data if required, are produced. And if there’s a power outage, battery back-up means nothing is lost.

Preventing Loss with Early Warnings

Advanced systems using dual probes can also provide an additional level of protection. One probe measures air temperature inside the fridge and should be placed in the middle of the fridge, adjacent to the vaccines, while a second probe is placed inside a load bottle designed to mimic the thermal response of vaccine product.

This enables operators to detect fridge failure early, before the vaccines themselves move outside safe temperature limits, allowing time to relocate stock and avoid costly wastage.

Compliance and Audit Readiness

Temperature records must be secure, accessible and tamper resistant. For regulated environments, especially organisations operating under GLP, GMP, GDP or 21 CFR Part 11 requirements, cloud-based data logging systems - such as Ratifi Cloud software which is used with Signatrol’s Cadmus system - offer many benefits not only for data security but for compliance to ensure a smooth audit process. Long term encrypted data retention along with automated daily, weekly or monthly reports which can be exported to PDF or CSV means users can have full audit trails of changes and activity to demonstrate compliance to the auditor.

Annual Review and Ongoing Assurance

All vaccine storage equipment and procedures should be audited at least annually, with more frequent review where previous failures or risks have been identified.