Food Safety

Root Cause Analysis

Food Safety 101

Food businesses occasionally encounter situations where product non-conformances have compromised food safety or quality or led to an outbreak of foodborne illness. This may lead to the business needing to dump product or undertake a costly recall or withdrawal.

Root cause analysis is a technique that uncovers the true cause of product contamination or quality problems and supports identification of effective actions to eliminate the problem, prevent recurrence, and reduce risk.


Root cause analysis (RCA): an investigative approach used to determine the underlying cause of a system failure

Contributing factor: the specific environmental, biological, procedural, or behavioural factors that result in failure e.g. failure of sanitation, incorrect storage temperature, inadequate supervision

The RCA determines why something has gone wrong; while establishing contributing factors clarifies what actually went wrong.

Performing the RCA

RCA provides a structured proactive approach to incident investigation, allowing more effective long-term solutions that prevent such incidents from recurring.

Describe the incident

Identify what occurred and provide a full description of the incident

Categorise the immediate cause

Establish which systems may have failed resulting in the incident

Determine the root cause

Identify causes and events leading to incident, by brainstorming, using the five whys, or Ishikawa diagrams

Define preventative measures

Identify measures and corrective actions that resolve the failure and minimise the likelihood of recurrence

Various techniques are used to determine how and why a food safety issue has occurred.

The five whys involve repeatedly asking the question WHY? This allows the investigator to scrutinise contributing factors to reveal the underlying root cause of a problem or incident.

While Ishikawa (fishbone) diagrams involve a type of cause-and-effect approach that evaluates factors that may have contributed to an incident (materials, environment, people, equipment and procedures).



The analysis will provide information on the underlying cause(s) of an incident and help establish the chain of events leading to its occurrence.

Pitfalls to avoid when undertaking an RCA include:

  • Focusing on contributing factors rather than on the root causes
  • Using personnel who lack sufficient investigative skills and knowledge
  • Failing to ask the right questions
  • Identifying a single root cause when there may be many

The outputs of an RCA support post-incident review processes, leading to changes to a business's food safety program.


EXAMPLE: Salmonella-contaminated packaged salads cause an outbreak of foodborne illness

Contributing factors: An extreme rainfall event led to increased soil contamination of fresh produce just prior to harvest, and product washing and sanitation was insufficient to control Salmonella contamination

Root causes:

  • Insufficient scientific knowledge of risk factors (rainfall event) to predict likelihood of Salmonella contamination on incoming raw materials
  • Inadequate control measures (washing and sanitation) of finished product resulting in Salmonella survival on product
  • Company culture did not adequately understand product risks and failed to implement appropriate control measures in the food safety program

Investigating food contamination events and issues helps uncover weaknesses in food safety programs and supports enhanced preventative-based controls.


Pew Charitable Trusts (2020). A Guide for Conducting a Food Safety Root Cause Analysis

Food Standards Agency. An introduction to Root Cause Analysis Course.

This is a general guide and does not comprise or replace technical or legal advice. We do not guarantee the accuracy or completeness of the information. Links to website are provided as a service and do not constitute endorsement. IFPA accepts no liability arising from, or connected to, or loss due to any reliance on this document.

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