Standard Operating Procedures

At a Glance

What it is

The result of the SOP method is a comprehensive document that outlines processes in the lab and identifies hazards and controls to eliminate or mitigate the risks.

Who's involved

Principal investigators and senior lab workers oversee the SOP process, but everyone working in the lab should contribute and participate.

When to use  

Scenarios where hazardous materials, equipment, or processes have been identified but could be streamlined for simple experiments, well-tested experiments, or those that are unchanging.

Training required

Principal investigators and senior lab workers should lead SOP development. All lab workers at all experience levels should participate in SOP development, review, and updates.  


Standard Operating Procedures (SOP) work well for designing experimental protocols in general. It provides an opportunity to identify risks and hazards at each step of an experimental process. An effective SOP analyzes potential hazards associated with a number of factors ranging from the types of materials the experiment requires, to the people working in the lab. Based on the identification of these hazards and risks, SOPs help predict what could go wrong and assess the impact of a safety failure.

Learn more about hazard identification factors to assess.

The SOP often includes information collected from a checklist, Job Hazard Analysis, What-if Analysis, or control banding.

SOPs are typically developed for repetitive procedures known to have associated hazards, such as injury, property loss, or loss of productivity. The SOP outlines written steps that can be followed to safely execute the procedure. Each step of the experiment can be analyzed separately to identify failure points. After each step is analyzed for potential dangers, the whole experiment process should be examined from beginning to end to determine if combinations of the factors could impact safety.

The lab worker uses the hazard matrix to review the risks associated with the use of hazardous materials, hazardous processes, and hazardous equipment. They also measure impact of conditions including: adequacy of facilities, worker knowledge and experience and proposed hazard mitigation measures.

SOP Messages to Remember

When writing an SOP, make sure the appropriate research was performed to understand the hazards and identify safety measures including a review of past incidents.

Consult with coworkers, vendors, or other experts.
They may point out hazards you hadn’t considered or known about. For example, compressed gas vendors can explain appropriate handling. Include warning or trouble signs and what to do to prevent a lab accident. Submit the SOP for review by a supervisor and other laboratory workers.

Review literature and other guidance materials.

  • Consult the Safety Data Sheet for specific hazards of gas to be used.
  • Consult National Fire Protection Association codes (the safety office can obtain these) for control requirements for gas in storage and use, including tubing and connectors, emergency response equipment and facilities requirements.
  • Review the literature for lessons learned.
  • Review the experiment for what could go wrong/likely failures?
    - What failures, even if unlikely, could lead to a catastrophic event?

Prepare for the experiment.

  • Remove any combustible or unnecessary material from the area around the experiment.
  • Make sure there is a clear emergency egress, and have appropriate attire and PPE.
  • Have a plan to monitor the experiment.
  • Review the hazards and make sure measures have been taken to reduce risk.
  • Address other laboratory or facility operations that might affect this experiment or be affected by it.
  • Practice using nonhazardous materials or using a scaled down process.

Identify unsafe conditions

  • Do not perform an experiment in low humidity, with inadequate space or lighting, or in a cluttered or cramped area.
  • Do not perform while working alone or without emergency response personnel, if needed.
  • Do not perform an experiment if rushed, fatigued, or ill.
  • Do not proceed if there is evidence of a gas leak or a tubing or equipment failure.
  • Report any incidents or concerns to a supervisor.


  • Easily referenced by laboratory workers.
  • Helps students apply critical thinking and understand how to evaluate potential risks as a matter of habit.
  • Familiarizes students or less experienced lab workers with multiple well-described hazard analysis methods: Job Hazard Analysis (or task analysis), What-if Analysis, checklists, control banding (by supervisors), and others.


  • Time-consuming and tedious, compared with other methods.
  • More experience is needed.
  • Potential to overlook a hazard. (Supervisor review is recommended.)
  • Lab workers may be resistant to using this more time-consuming method.

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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