Several years ago, NASCAR decided to let the drivers decide for themselves what was best for them. The thought was (in part) to make it the driver's responsibility and take the liability off of the sanctioning body. Steve Hearn learned about this at one of the motorsports conferences and brought the same thinking to our rules. NASCAR had second thoughts and changed their rules back to what they had before... but APBA never changed. You can see that in wording of the opening line from the GSR below. We have had discussions about tightening the rules back up by calling out acceptable Snell, ANSI, DOT and/or mil spec info, putting time limits on helmets, clarifying color, etc. Problem is that every manufacturer has different dating processes (or sometimes no date stamp / sticker at all). And we always get into the poor guy who's 20 year old helmet still looks like brand new. It's a slow and tedious process.
From the APBA General Safety Rules:
Considering the fact that there is no safest life jacket and helmet that will eliminate all risks, the participants are solely and ultimately responsible for
selecting a suitable helmet and life jacket. Only those considered in good condition may be used.
A. Helmets must meet the specifications set forth by any of the following: Department of Transportation, American National Standards Institute, Inc., Snell, or military specification helmet designed for military aircraft Mil-Spec helmets (CGF LA100, LH050, LH150, LH250; Gentex HGU84P)and Peltor helmets (Rally Pro Helmet EN ECU 04 or 05) are acceptable.
So as it stands, if you have a Snell sticker (any year) and there is no obvious damage... your are self certifying that your helmet is what you believe is the safest thing you can wear. Be aware, that may change in the very near future. The color rule goes into effect on Nov. 1, 2011. The upper 50% must be a solid color and orange / yellow... I don't remeber the exact wording.
My recommendation: If you are buying a new helmet, by from one of the best known manufacturers (Shoei, SRP, Bell, Simpson, Impact, etc) that have the latest Snell date (2005 or 2010). I would avoid helmets only certified to DOT standards. ANSI and mil spec helmets are also acceptable, but not as readily available.