Exposure Incident Root Causes

Exposure incident root causes

Identifying the root cause of an exposure incident, including the underlying reasons why it occurred, is an important step in the investigation of incidents and helps inform measures to prevent similar incidents in the future.

In 2025, the leading root causes cited in confirmed exposure incidents were human factors (72.9%), training (48.6%) and standards, policies and procedures (45.7%).

Root cause analysis begins by identifying the conditions and related factors that may have contributed to an incident. Investigators can then examine how these factors are connected by asking a series of questions, such as “why did this happen?” or “what caused the problem?”. Each answer prompts another “Why?”, allowing the analysis to move beyond the immediate causes and uncover underlying issues. Mapping these cause-and-effect pathways helps identify the factors that led to the exposure and supports the development of targeted corrective actions.

For example, if a laboratory exposure occurred because personal protective equipment was not worn, asking “why” may reveal that the equipment was not readily available. Asking “why” again may show that restocking procedures were unclear or inconsistently followed. Addressing these underlying issues, rather than the single action, helps prevent similar incidents in the future.

In the exposure incident follow-up form, six main categories of root causes are identified, as well as an “other” category for any root cause that do not fall within the main categories:

• Human factors
• Standards, policies, procedures
• Training
• Communications
• Management oversight
• Equipment
• Other

More than one root cause may contribute to an incident, therefore all applicable root causes should be identified and selected. Human factors can also be related to standards, policies, procedures, training, communication, management and oversight or equipment and work environment. When selecting these specific human factor options, the same root cause must be selected later in the form; otherwise, you won’t be able to save the form. For instance, for incidents where a root cause is human factor related to equipment, you must also select “equipment” as a root cause.

Guidance on conducting root cause analyses is available in:

• Chapter 5 of the Canadian biosafety guideline: Incident investigation;
• The Canadian Biosafety Guideline: Notification and Reporting Under the Human Pathogens and Toxins Act and Human Pathogens and Toxins Regulations Using the Reporting Module of the Biosecurity Portal, section B.1.1 outlines the criteria for conducting a thorough investigation;
• A podcast on the main root causes identified in exposure reports is also available in the PHAC Training Portal.

According to section 13 of the Human Pathogens and Toxins Act, licence holders must report without delay when they have reasonable grounds to suspect that an incident involving a human pathogen or toxin in their possession has, or may have, caused disease in an individual. This includes incidents where there are reasonable grounds to suspect an exposure that is capable of resulting in disease, even if disease has not yet manifested. Failure to report is an offence and may result in enforcement actions depending on the severity of the infraction, including:

• the issuance of a notice of non-compliance
• changes to licence conditions
• an increase in inspection frequency, or
• prosecution