I'm posting this info from a correspondence I'm having with a Snell Foundation representative, I thought it might interest some of ye
I asked about the CPSC standard vs the Snell and also about the differences between the Snell B95A and B90A and that was the reply:
"The CPSC standard is the mandatory standard for bicycle helmets in the US.
All bicycle helmets in the US must meet the CPSC standard by law. But The
CPSC standard is a self-certifying standard, which means that the helmet
manufacturer is responsible for making sure that its products is CPSC
compliant. CPSC does perform some random testing to check on helmet
compliance, but no manufacturer has to submit helmets for CPSC for testing
and approval before bringing its products into the market.
Snell standards are voluntary but are more stringent than the government
mandatory standard CPSC. All Snell certified helmets must pass a complete
comprehensive certification testing process at the Snell lab to be
certified. Production and distribution of those certified helmet will carry
a Snell certification sticker with a unique serial number to track production
quantity. Then Snell buys back random samples of certified helmets in the
market place based on production quantities to verify the performance of
those helmets sold to the public. The difference in the Snell B-90A
standard and B-95A standard is that the B-95A standard requires more areas
on the helmet be tested for impact protection in the back of the head. Some
helmets certified to the B90A standard is styled in such a way that the back
of the head is not covered by sufficient amount of impact absorption foam
and thus will have trouble passing the B-95A standard testing.
Snell certification tests are pass or fail testing under different
environmental conditions (Hot, Cold, Wet, Ambient) onto different impact
surfaces. A helmet sample that does well in one condition or on one surface
may not do so well in another. Only when all tests pass the standard
requirements, a helmet model and size becomes Snell certified products. So
we cannot rank one helmet model against another. Basically when a helmet
become Snell certified, it means we strongly recommend that helmet model to
the general public. Snell certification means that it is the most protective
headgear available in the market. "
so as far as I understand now the B95A certification is the most demanding standard for bicycle helmets,
on the Snell website here ( http://www.smf.org/cert ) one can find a list of helmets that have achieved this standard, I think its interesting to note
that amongst them are some Chinese lower-cost helmets as well, now i'm trying to figure out which of these helmets listed there is available to purchase in USA and where however the helmet I'd care to use must be regular and not the full-face DH style....