Top 10 IFU Pitfalls That Cause Retesting

Introduction

Retesting is expensive and time consuming, whether it’s repeating a cleaning validation because your reprocessing steps weren’t fit for purpose, or reformatting instructions because end users couldn’t follow a critical step on paper.

The good news: most retests stem from a familiar set of IFU pitfalls you can spot early.

Below are the ten most common traps, how they trigger retesting, and what to do instead.

1. Unvalidated Instructions

The pitfall: IFU steps (especially reprocessing) are not backed by validation under clinically relevant soils, equipment, water, and load.

What happens: reviewers ask for evidence; you repeat lab work (e.g., cleaning validation) under recognised methods.

Fix: Follow guidance from ISO 17664 and AAMI TIR12 depending on your market or have a structured dialogue with your Notified Body, when structuring your IFU. When gathering evidence for your claims, it’s important to keep your intended purpose relevant.

2. Assuming Equipment Users Don’t Actually Have

The pitfall: Validating reprocessing or use steps on equipment that isn’t common in the target market (e.g., expecting a small dental practice to run a washer‑disinfector).

What happens: sites can’t reproduce your instructions, regulators question “representativeness”, and you repeat validation with realistic equipment/chemistries.

Fix: Ensure IFU claims reflect the resources a typical facility actually has and validate accordingly.

3. Writing for Engineers and Auditors, Not the Actual End-User

The pitfall: Dense text, jargon, and no visuals; instructions that read like a tick‑box exercise for compliance.

What happens: Critical tasks fail in real clinical use, forcing manufactures to reformat the IFU, gather new sets of evidence and placate upset customers.

Fix: Use Plain language (step‑wise, action verbs, graphics that match steps, etc). The FDA have a great article on this topic “human‑factors guidance and the IFU Content/Format recommendations”.

4. Fuzzy Scope: Users Can’t Tell Which SKUs the IFU Covers

The pitfall: One IFU “covering” a family, but it’s unclear which models, configurations, or accessories it applies to.

What happens: Auditors request clarification, corrective edits, and, if the IFU covers a very large portfolio of devices, additional testing.

Fix: ISO 20417 and MDR Annex I require clear identification of the device, manufacturer, and relevant accessories. Spell this out in the first page and in a dedicated “Applicability” section.

5. Missing Disassembly and Other Hard‑to‑Do Steps

The pitfall: Complex devices need disassembly, instrument specific tools, or nuanced alignment when reprocessing, some IFUs are inadequate in this respect.

What happens: Cleaning/sterilisation validation fails due to user error.

Fix: Map every critical task from your usability/risk analysis into the IFU and validate accordingly, reference the IFU guidance tables listed standards like AMI TIR12 or ISO 17664.

6. Skipping Maintenance & Life Extension Guidance

The pitfall: No scheduled inspection, lubrication, or part replacement guidance; no wear limits.

What happens: Premature failures or safety complaints send you back to update the IFU and, in worse cases, re‑evaluate risks/usability.

Fix: Include maintenance and inspection intervals following guidance from “information supplied by the manufacturer” (ISO 20417), aligned to the device’s intended lifetime.

7. Device IFUs Conflicting With Chemical IFUs

The pitfall: A reusable device’s IFU specifies neutral‑pH cleaning and lists contraindications for alkaline chemistries, while the end-user facility’s standard detergent IFU is high‑pH (≈pH 10–12) and/or requires parameters (e.g., temperature, dwell time) that don’t match the device IFU.

What happens: End-users are left to improvise resulting in the device IFUs not being followed and no one wanting to take responsibility.

Fix: Maintain a live table mapping device families to permitted chemistries or put a clear precedence rule in your reprocessing policy I.e. “When an unresolvable conflict exists between a device IFU and a detergent/consumable IFU, the device IFU prevails for device‑specific processing.”

8. Not Taking a Worst‑Case Approach to Generating Evidence

The pitfall: Validations are run under ideal lab conditions, using easy‑to‑reprocess devices, lab‑grade water, generous contact times, freshly manufactured devices, and equipment that isn’t typical for the target setting. The IFU “works” in the lab but fails in real clinics under scrutiny.

For reusable devices, this often means soils aren’t sufficiently challenging, end‑of‑life wear isn’t simulated, and the most restrictive load/packing configurations aren’t tested.

What happens: Reviewers question reproducibility at user sites and request additional, more representative validation runs, evidence generation.

Fix: Work internally or with a reputable partner to define “worst case” at the beginning, across device conditions (e.g., end‑of‑life cycles), soil challenge, load/packaging density, and environmental utilities (e.g., water quality per ST108).

9. Weak Packaging & Storage Details

The pitfall: Missing or vague storage conditions, shelf‑life cues, or packaging compatibility; symbols used inconsistently.

What happens: label/IFU nonconformities leading to confusion, and corrective rounds on labelling and verification.

Fix: Use ISO 20417 for required “accompanying information,” ISO 15223‑1 for standardised symbols (e.g., temperature, keep dry, use‑by), and satisfy MDR Annex I legibility/format requirements within your IFU.

10. Out‑of‑Date Contacts & Poor Version Control (Paper & eIFU)

The pitfall: Obsolete addresses/URLs, multiple live versions online, or no change controls in place.

What happens: Someone will flag access to superseded instructions leading to reissue of the latest IFU version and sometimes retraining where applicable and the dreaded impact assessments.

Fix: Keep website and eIFU content current and run a formal change‑control/retirement process.