The 4 Most Common Mistakes in the Risk Acceptance Matrix

Bernhard Lindner
Feb 23, 2023
2 min read

Updated: Feb 7, 2024

In the past, medical device manufacturers have used risk acceptance matrices with large green areas where the occurrence of damage was acceptable. Today, this indicates that something is wrong with the risk acceptance matrix. In this article we show you the 4 most common mistakes when using the risk acceptance matrix and how to avoid them.

Mistakes in the Risk Acceptance Matrix

What errors does this risk acceptance matrix contain?

Risk Acceptance Matrix with mistakes that are often found at medical device manufacturers

Risk Acceptance Matrix Mistake No. 1:

According to MDR Appendix I, chap. I, paragraph 1, are risks (related to harm to patients/users/third parties) are only acceptable if they are "minimized as much as possible" and "reasonable compared to the benefits". This means that there must be no per se acceptable risks in the risk acceptance matrix about harm to patients/users/third parties. In this form, the green fields are therefore wrong as acceptable per se.

Risk Acceptance Matrix Mistake No. 2:

ALARP is not allowed. The MDR Annex I, chap. Paragraph 1 clearly states that risks must be minimized "as far as possible". Annex C of CEN ISO TR 24971:2020 specifies several approaches. However, here the MDR's legal requirements beat the standard's requirements.

Risk Acceptance Matrix Mistake No. 3:

There are no fields for the acceptable occurrence of catastrophic damage. Since no acceptable occurrence of catastrophic damage can be achieved, it is impossible to bring these risks to an acceptable level. Catastrophic damage is, therefore, never acceptable. The acceptance limit for these damages is not shown.

Risk Acceptance Matrix Mistake No. 4:

For negligible damage, there are no fields for unacceptable occurrence. Negligible damage is always acceptable. Thus, there is no acceptance limit for negligible damage.