Understanding hazard analysis terminology

Your updated ‘cheat sheet’ to hazard analysis terminology in medical devices. (May 2020)

We’ve already seen how a key part of ensuring functional safety is a robust risk management system. The first step in risk management is assessing risk; a key initial part of that first step is hazard analysis. Simply put, a hazard is a potential source of harm caused by the system in question malfunctioning. Hazard analysis is the process of identifying them, documenting their consequences and analysing their causes.

I’m now one paragraph into this post and already we are coming across a number of terms that could be confusing to non-specialists. Risks sound pretty similar to hazards don’t they? Well, no, not exactly. Functional safety is by its very nature a discipline where precision is important and in addition, clarity is a key prerequisite for any form of standardisation.

In the world of medical device safety where accuracy is everything, misinterpreting a word would cause a lot of confusion and misunderstanding. That’s where the expertise of consultants who live and breathe industry standards and regulatory compliance becomes invaluable as we share our knowledge and experience with you.

Since we first published this blog entry in 2015, there have been a number of updates to the standards in the medical device sector hence we thought we would update our list.  So to help you on your way, here’s a simple cheat sheet of the latest definitions of hazard analysis terminology as defined in the various medical device standards:

BASIC SAFETY – freedom from unacceptable RISK directly caused by physical HAZARDS when ME EQUIPMENT is used under NORMAL CONDITION or SINGLE FAULT CONDITION. Confusingly, by the way, if you look up the definition in IEC 60601-1, you’ll see it says ‘NORMAL CONDITION and SINGLE FAULT CONDITION’ but it’s not ‘and’ in the sense of a logical conjunction; here it actually means ‘or’.

ESSENTIAL PERFORMANCE – performance of a clinical function, other than that related to BASIC SAFETY, where loss or degradation beyond the limits specified by the manufacturer results in an unacceptable RISK.

HAZARD – a potential source of harm – caused by the system in question malfunctioning.

HAZARDOUS SITUATION– circumstance in which people, property, or the environment are exposed to one or more HAZARD(S).

HARM – physical injury or damage to the health of people or animals, or damage to property or the environment.

HEALTH S – SOFTWARE SYSTEM intended to be used specifically for managing, maintaining, or improving health of individual persons, or the delivery of care, or which has been developed for the purpose of being incorporated into a MEDICAL DEVICE

INTENDED USE/INTENDED PURPOSE – use for which a product, process or service is intended according to the specifications, instructions and information provided by the manufacturer

MEDICAL ELECTRICAL EQUIPMENT (ME EQUIPMENT) – electrical equipment that has a part that comes into physical contact with the patient during NORMAL USE or that transfers energy to or from the patient or that detects such energy transfer to or from the patient. It is also:

1. provided with not more than one connection to a particular mains supply; and
2. intended by its MANUFACTURER to be used:

•                in the diagnosis, treatment, or monitoring of a patient; or
•                for compensation or alleviation of disease, injury or disability.

NB, ME EQUIPMENT also includes those accessories as defined by the manufacturer.

NORMAL CONDITION – the condition in which all means provided for protection against HAZARDS are intact.

NORMAL USE – operation, including routine inspection and adjustments by any operator, plus stand-by, according to the instructions for use. NB, NORMAL USE should not be confused with INTENDED USE. While both include the concept of use as intended by the manufacturer, INTENDED USE focuses on the medical purpose.

REASONABLY FORESEEABLE MISUSE – use of a product or system in a way not intended by the manufacturer, but which can result from readily predictable human behaviour

RISK – combines the probability of occurrence of harm and the severity of that harm. Risk can be either acceptable or unacceptable.

RISK ANALYSIS – systematic use of available information to identify HAZARDS and to estimate the RISK.

SINGLE FAULT CONDITION – a condition of ME EQUIPMENT in which a single means for reducing a RISK is defective or a single abnormal condition is present.

STATE OF THE ART – developed stage of technical capability at a given time as regards products, processes and services, based on the relevant consolidated findings of science, technology and experience