At a Glance

What it is

A technique using brainstorming to determine what can go wrong in specific scenarios and identify the resulting consequences.

Who's involved

Appropriate for both individuals and teams.

When to use

  • Simple research applications
  • Complex processes
  • Research environment, where teaching is the core mission
  • Assessing existing processes and experiments

Training required

Minimal. Requires someone to be familiar with the equipment, processes, etc.


What will happen if toxic gases leak into a liquid pipeline? What if tank feed is increased or decreased? What if an earthquake occurs? Such questions can be critical in reducing or eliminating risks to people working in a laboratory environment.

A What-if Analysis consists of structured brainstorming to determine what can go wrong in a given scenario; then judge the likelihood and consequences that things will go wrong.

What-if Analysis can be applied at virtually any point in the laboratory evaluation process.

Based on the answers to what-if questions, informed judgments can be made concerning the acceptability of those risks. A course of action can be outlined for risks deemed unacceptable.

How to Conduct a What-if Analysis

1. Team Kickoff

The team leader walks the team through each step of the What-if Analysis. The leader may use a detailed equipment diagram along with any prepared operating guidelines. (Include guidelines for determining acceptable level of safety.)

2. Generate What-if Questions

The team generates What-if questions relating to each step of the experimental procedure and each component to determine likely sources of errors and failures.

Things to consider when developing questions:

  • Potential human error
  • Equipment component failures
  • Deviations from the planned/expected critical parameters (e.g., temperature, pressure, time, flow rate)

Learn more about these and other factors to assess when identifying hazards

Sample What-if Analysis Questions

3. Evaluate and Assess Risk

The team considers the list of What-if questions, one-by-one, to determine likely sources of errors. They then decide the probability of each error occurring and assess the consequences.

How to Assess Risk

4.  Develop Recommendations

Risk deemed unacceptable:
If the team concludes there’s a need for corrective action, a recommendation is recorded.
Risk deemed acceptable:
When probability is very low, consequences are not severe, and the action to correct the condition would involve significant cost and time, the team may note a “no recommendation” response.

5. Prioritize and Summarize Analysis

The team’s analysis is summarized and prioritized.

6. Assign Follow-up Action

Responsibilities are assigned for follow-up action(s). Consider adding a column to your What-if Analysis form to indicate the person or group responsible for each corrective action.


  • Easy to use
  • No specialized tools needed
  • People with little hazard analysis experience can participate meaningfully
  • Leads to deeper insight, especially for person/people conducting the analysis


  • Only useful if you ask the right questions
  • Relies on intuition of team members
  • More subjective than other methods
  • Greater potential for reviewer bias
  • More difficult to translate results into convincing arguments for change

Sample What-if Questions

Following is a list of sample What-if questions to get your group thinking in the right directions. These questions can be modified according to experiment or process.

Human Factor

Human errors occur regardless of training and experience. Human error factors may drive consideration of written SOPs, a decision for engineering controls, etc.

  • What if material used is too concentrated (or diluted)?
  • What if the valve/stopcock does not open (or close)?
  • What if the valve(s) are opened (or closed) in the wrong sequence?
  • What if inert gas is omitted?
  • What if unintended materials are mixed together?
  • What if readings are missed or ignored?
  • What if warnings are missed or ignored?
  • What if there are errors in diagnosis?


The following questions concern utilities, which are key to the support of any experiment or process:

  • What if power is lost?
    Consider: Automatic shutoffs and emergency power
  • What if power is restored automatically after loss?
    Consider: Manual restarts
  • What if laboratory ventilation is lost?
    Consider: Automatic shutoffs, emergency power, and redundant mechanical exhaust fans

Experimental or Ancillary Equipment

Consideration of failure of materials or components may result in decisions for additional controls or changes to higher rated or alternative types of materials and components.

  • What if there’s unexpected over-pressurization?
    Consider: Pressure relief devices and barriers; personal protective equipment (PPE)
  • What if glassware breaks during reaction?
    Consider: Spill control; PPE
  • What if there’s a failure of equipment cooling?
    Consider: Alarms, automatic shutoffs, and emergency shut-off procedures

Personal Protection

This should be included since, despite best efforts with hazard reviews and training, incidents will occur.

  • What if a body is impacted by liquids or solids?
    Consider: Physical barriers
  • What if someone is exposed to vapors or gases?
    Consider: PPE; ventilation
  • What if someone is exposed to respirable particles?
    Consider: Use of wet contamination control methods, ventilation controls, and respiratory protection

This collection of methods and tools for assessing hazards in research laboratories is based on the publication, Identifying and Evaluating Hazards in Research Laboratories [PDF]. The guide was published in 2015 by the Hazard Identification and Evaluation Task Force of the American Chemical Society’s Committee on Chemical Safety in response to a recommendation from the U.S. Chemical Safety Board.

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