Helmets?

SCCA, NASA, TrackDaze ... (the ones I'm familiar with) allow Snell M rated

http://www.nasaforums.com/viewtopic.php?f=42&t=103519&sid=27dcdcb0ab49cd4357621c8dce81bb78

Chin also allows M-rated helmets.
http://www.chinmotorsports.com/forum/topic.asp?TOPIC_ID=1551

In reply to JKleiner: Thanks for sharing a few specific clubs that require Snell SA. It's certainly important for people to know that some track day organizing groups require Snell SA helmets.

However in addition to the previously noted common national motorsport sanctioning bodies with more relaxed Snell M requirements, most manufacturer specific enthusiast organizations I have seen (BMWCCA, PCA, etc.) and most local/internet-based sports car club organized events I have seen tend to run a Snell M base requirement as well.

In other words, people should always check what the various events at their intended tracks require so they know what is or is not specifically required. If there are events you are likely to try running with a Snell SA requirement, then it would certainly be more beneficial to buy into a Snell SA helmet at that point than if all of the events you'll might be running require nothing more than a Snell M...Especially if somebody is just getting into it and/or may already have a Snell M helmet on hand. Once again, with that being said, you'll also never have to worry about being left wanting with a Snell SA either