What is an insidental spill?

Answer 1

This is all I could find. There are many sites but this is the basic definition. Hope this helps you.

Minor and Incidental Spills
Minor and incidental spills will not cause immediate injury, are contained, and have no risk of fire. For minor spills, you will need technical assistance with spill cleanup and you might need an outside contractor to do the cleanup for you. For incidental spills, you are prepared to clean up the spill yourself with no risk to you and those nearby.

To decide whether you have a minor or an incidental spill, ask yourself:

Do you know what chemical was spilled?
Do you know the hazards of the spilled chemical?
Can you protect yourself from these hazards with protective equipment?
Do you have and know how to use a chemical spill kit for this chemical?
If you answered NO to any of the above questions or need assistance with the spill cleanup, you have a minor spill. Evacuate and secure the area and seek assistance.

If you need technical assistance during business hours, call our EH&S "Chemical Spills Hotline" at 206.543.0467. When in doubt about whether you need our help or not, call us; we can help you decide what to do.

If you need technical assistance after business hours, call 911 to reach EH&S for technical assistance. Explain that you have a minor spill and that no one is in immediate danger, and that you would like to talk with someone at EH&S who can help you determine if you have a minor spill or an incidental spill.

For a proactive audit of your lab safety program and chemical spill readiness, call 206.543.0467