The Helmet Update
Volume 16, Issue 2 - February, 1998
BHSIDOC#590
All issues index
CPSC Approves New Standard
To Take Effect in March, 1999
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.
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now withdrawn by ANSI as outdated.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.
Issues
Child Helmets
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.
Reflectivity
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 lives.
Updating
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.
Summary
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.
Key Provisions of the New CPSC Standard
Anvils: Flat, hemispherical with 47 to 49 mm radius, and curbstone
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 anvils.
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 details.
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 headform.
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
lab.
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 sides.
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)
BHSI News
(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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The Helmet Update - Bicycle Helmet Safety Institute
Randy Swart, Editor
4611 Seventh Street South
Arlington, VA 22204-1419 USA
(703) 486-0100 (voice)
(703) 486-0576 (fax)
www.helmets.org