The Helmet Update
Volume 16, Issue 2 - February, 1998
Previous Issue: November, 1997
CPSC Approves New Standard
In late December the Consumer Product Safety Commission released the final draft for its
bicycle helmet standard. The Commissioners were briefed on this draft on January 21, and
approved it unchanged on February 5. It will become the U.S. law for helmets in March,
1999, and has some provisions that are effective immediately.
To Take Effect in March, 1999
The new standard is good news for consumers. As an interim measure, CPSC has been
enforcing a legal requirement for helmets sold here to meet one of seven designated
voluntary standards, but one of them was the old 1984 ANSI standard, now withdrawn by
ANSI as outdated. This new CPSC standard raises the bar, increasing the minimum to
levels similar to the current ASTM and Snell B90S standards. That means, for example,
doubling the drop height on the flat anvil in the certification tests, and adding a test for
stability (rolloff). It also limits projections on helmet shells to 7 mm, a provision left out of
the ASTM standard. Virtually any well-made helmet on the market today should meet this
standard without major modifications except those with very large projections or points
jutting out from the shell.
CPSC has eliminated the special provision for child helmet testing which would have
lowered the headform weight from the adult weight now used (5 kg) to a level more
consistent with child heads (3.9 kg). They have also eliminated the lowering of acceptable g
levels in the tests, which in their first drafts would have been 250 g rather than the adult
formula of 300 g. At the last minute before the January 21st briefing the Commission
received a letter from Jim Sundahl, the most brilliant helmet engineer in the Bell Sports
stable, asking that those provisions in earlier drafts for child helmets be retained. He
argued that child helmets should not be judged by adult tests, and that the result of that
today is toddler helmets with too-stiff EPS liners that do not crush as they should when a
toddler hits something hard. (The text of his letter is up on our website.) As a courtesy,
Sundahl's comments were considered by the Commission, but it was clear that the die was
cast before he wrote, and the public testimony on this standard had been taken in the course
of the previous three years as it was developed. We agree with Jim Sundahl, but understand
that CPSC was forced into its action by the contention of the injury prevention community
that today's helmets cannot be changed unless there is scientific data to support a need for
change. We never have that data as they define it in helmet standards-making, and many
changes have been made in the past based on the sort of unpublished observation and
analysis Sundahl presented--including the 300 g threshold, the drop heights used, the
headform weights, the strap strength tests, the rolloff tests, coverage requirements and
more. ASTM's infant toddler standard will be published this year with 3.2 kg and 4.0 kg
drop weights for child helmets, so there is hope that CPSC will eventually revise its
standard as well. We note with approval that the final CPSC rule does continue to require
additional coverage for child helmets, essentially reflecting what the market is already
providing in today's infant-toddler models.
CPSC has concluded that it will not require reflective material on the outside of helmets. A
CPSC study did not show improvement in recognition distances needed by approaching
drivers, and the material to be used is not currently available to manufacturers. We would
like to see the study redone with drivers who are inebriated, using controlled substances,
talking on cell phones and smoking cigarettes, to reflect more accurately the population of
drivers who run cyclists down at night. In the meantime we have to reluctantly concur with
the CPSC action on this issue despite our belief that reflective material on helmets can save
The most important news released at the January briefing was a statement by the office of
CPSC's general counsel that legally the Commission can update the standard with the same
procedure as the one by which it was adopted-bypassing mountains of red tape normally
required to put a CPSC standard in place or modify it. This is important because bicycle
helmet standards have been evolving rapidly over the past ten years as the technology has
changed and new injury information has come to light.
We are pleased that this draft has been approved and that the standard will take effect in
March of 1999. We hope that CPSC will not lose sight of the need to revise this standard
as new information and new technologies come to light, and that the infant-toddler helmet
tests in particular will be subject to periodic analysis.
Anvils: Flat, hemispherical with 47 to 49 mm radius, and curbstone
Key Provisions of the New CPSC Standard
Certification Process: Manufacturer must issue certificate based on a "reasonable testing
program." Can use tests prescribed in the standard or other test procedures assuring
compliance. At least one helmet from each production lot must be tested. If non-complying
helmets found, must ensure that "sufficient actions are taken that it is reasonably likely
that no noncomplying helmets remain in the production lot." Identified noncomplying
helmets to be destroyed or modified to conform.
Child Helmets: Helmets for children 1 to 4 years old must have additional coverage.
Conditioning Environments: (approx. in f degrees) Ambient: 68 degrees; Cold: 5 degrees;
Hot: 122 degrees. Wet: Immersed in water at 68 degrees. Conditioning times 4 to 24 hours.
Construction: Any optional devices must be unlikely to cause injury. Detachable
components must not make helmet unsafe if detached and helmet can still be worn. If any
part detaches during testing it must not present a laceration or puncture hazard or reduce
coverage of the head. External projections greater than 7 mm must break away or collapse
when impacted with forces equivalent to those produced by the applicable
impact-attenuation tests in this standard. No projections inside greater than 2mm.
Coverage: Test line slightly lower in rear than ASTM, slightly higher than Snell B-95.
Drop Apparatus: guided free fall using twin wire or monorail test rig onto a steel anvil
fixed on a rigid base. Drop assembly (headform plus support assembly without helmet) must
weigh 5 kg (11 lbs). Uniaxial accelerometer inside headform capable of measuring 1,000 g
with sensitive axis aligned within 5 degrees of vertical.
Headforms: ISO. Five sizes (A,E,J, M and O). Must be made of K-1A magnesium alloy.
Mass of each headform together with supporting assembly must weigh 5 kg. regardless of
size, including size A for toddler helmets.
Impact Energy Management: Acceleration recorded in headform not to exceed 300 g,
with flat anvil drop of 2 meters and drops of 1.2 meters on hemispherical and curbstone
Impact Sites: Anywhere above the test line, with sites selected for most severe test in
attempt to fail the helmet. First set of ambient, hot, cold and wet samples each impacted at
sites separated by 120 mm two times with flat anvil and two times with hemispherical anvil.
Second set of ambient, hot, cold and wet samples impacted once each on curbstone anvil.
Instructions for Use and Care: How to fit and fasten, reminder to replace after impact,
list of damaging substances. Fit instructions to accompany helmet.
Labels on Helmet: Requires durable, legible, easily visible labels. Certification label
stating compliance with CPSC standard, with name, address and telephone number of the
U.S. manufacturer, private labeler or importer issuing the label, uncoded month and year of
manufacture, name and address of foreign manufacturer if not made in U.S. (can be coded if
private labeler's name is on certificate), production lot number or serial number. Other
labels preceded by "WARNING" stating that no helmet can protect against all impacts,
serious death and injury may occur, must be fitted and attached properly to wearer's head,
impact damage may not be apparent, destroy or return to manufacturer for inspection after
impact, substances which may damage, recommended cleaning agents, refer to manual for
Labels on Packaging: Fitting and positioning instructions including graphic
representation, list of damaging substances.
Materials: Durable and resistant to exposure to sun, rain, cold, dust, vibration,
perspiration or products applied to the skin and hair. Should not degrade during
temperature extremes. Materials known to cause skin irritation or disease shall not be used.
Lining materials, if used, may be detachable. Warning required if hydrocarbons, cleaning
fluids, paints, transfers or other additions will affect the helmet adversely.
Positional Stability Test: With thickest pads in place, select headform size that partially
compresses all sizing pads. Place helmet on ISO full chinpiece headform according to
manufacturer's instructions. Tilt headform forward 45 degrees, attach hook to rear rim and
strap run over helmet and down to a test apparatus permitting a 4 kg weight to drop .6
meters and hit a stop, jerking the strap. Test is repeated with headform face pointing
upward, jerking helmet from front to rear. The helmet must not come off of the test
Record of Tests: Must keep records on paper or electronic media showing that helmet was
certified under a "reasonable testing program." Must keep records for three years and make
available to CPSC if requested within 48 hours if not on factory site. Record must identify
helmets tested, production lot, results including precise nature of any failures and specific
actions taken to address any failures. Original test record to be kept on paper by the test
Retention System Strength: Dynamic yank. Helmet is supported on a headform and
preloaded with bean bag filled with 5 kg of lead shot. Chin strap is fastened under two metal
rods 12 to 13 mm in diameter and separated by 75 to 77 mm, representing the jaw, from
which hangs the test apparatus, weighing a total of 11 kg including the 4 kg drop weight.
The weight is dropped for .6 meter to dynamically load the retaining system while the pre-
load falls away. Strap must remain intact and not elongate more than 30 mm (1.2").
Scope: Helmets for bicyclists: "Headgear that is either marketed as, or implied through
marketing and/or promotional information to be, a device intended to provide protection
from head injuries while riding a bicycle." Applies by U.S. law to all bicycle helmets offered
for sale in U.S. market. We hope that this definition will cover "toy helmets" found in the
bicycle section of a discount store.
Sequence of Testing: Two sets of four samples required. 1)Peripheral vision test on first
ambient sample. 2)Second ambient sample subjected to retention system stability (rolloff)
test. 3)Retention system strength tests on each of the first set of ambient, cold, hot and wet
samples. 4)First set of ambient, cold, hot and wet samples subjected to 2 impacts each in
different locations on flat and hemispherical anvils. 5)Second set of ambient, cold, hot and
wet samples tested for impact attenuation with a single impact on the curbstone anvil.
Vision Impairment: Peripheral vision of 105 degrees from centerline required on both
Visors and Mirrors: Helmets must pass all tests both with and without any attachments
that may be included.
We expect to have full copies of the official version of the standard by the end of
February, on our website and available by request on paper.
Anyone who had given us an email address got this information much sooner! (See below)
(Added for this website version)
Our website is celebrating its third birthday this month. We updated our Internet
link and increased speed by about 25 per cent last fall. That forced an update of our
web server machine as well. In 1997 we added another domain name: helmets.org (the old one
still works) because nobody can remember our initials. On the web we have articles from
this newsletter with more detail, a Toolkit for Helmet Promotion Programs, our latest
helmet laws list, annotated bibliography, Most Asked Questions About Bicycle Helmets,
helmet standards comparison and a lot more.
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from you and welcome inquiries by any means.
Editor, The Helmet Update