Final 10/18/2007 STANDARD
FOR PROTECTIVE HEADGEAR
For Use in Children’s Motor Sports Activities
FOREWORD
In
motor sports accident, participants may suffer injury or death. Helmets on the market today offer varying
degrees of protection, but the consumer has little basis for judging the
relative effectiveness of a given model.
This Standard presents rational methods for identifying those helmet
models which definitely meet specified standards for impact (crash) protection
and retention system strength and, afterwards, identifying those which definitely have ceased to meet
these standards.
The
Snell Memorial Foundation and the Federation Internationale de l’Automobile
(FIA) urge that protective helmets be required for all individuals participating
in supervised racing events and encourage the general public to wear helmets
which meet appropriate performance standards1. To this end, the Snell Memorial Foundation
and the FIA jointly announce this Standard for children’s motor sports helmets.
This
Standard does not establish construction and material specifications.
This
Standard establishes performance characteristics suitable for children’s use in
motor sports involving motorcycles, power boats, karting, all-terrain vehicles
and snowmobiles. Manufacturers
voluntarily submit helmets to be tested to this Standard and if the submitted
helmets pass, a certification is issued.
The
Snell Memorial Foundation and the FIA will make available the identity of those
products which have been certified.
These products are for both competition and general use for the age
categories and activities specified.
All
of the requirements described herein, including both initial certification and
random sample testing, are an integral part of this Standard. No helmet can satisfy the Standard unless it
is subject to both certification and random sample testing.
Snell/FIA
certification for protective headgear requires a specific contractual agreement
between the primary headgear manufacturer and the Foundation. Certification procedures may be obtained upon
application to the Foundation.
SNELL
MEMORIAL FOUNDATION is a registered certification mark. CMH (Children’s Motor Sports Helmet)
is a certification mark jointly held by the Snell Memorial Foundation and the
FIA.
QUALIFICATIONS FOR CERTIFICATION
For
qualification testing, helmets shall be in the same condition as those offered
for sale. No helmet or component which
has been subjected to any tests described in this Standard shall be offered for
sale after testing. At least five (5)
and as many as seven (7) complete helmets must be submitted by the manufacturer
for a certification test program for each distinct structural configuration of
the models offered for sale. All but one
of these samples will be destroyed in testing; the untested sample shall be
retained for comparison and reference.
If different fit pad configurations are planned in order to accommodate
this head gear for different size ranges, five of the samples submitted must be
configured for the largest size range.
If seven samples are considered necessary, the remaining two samples
must be configured for the smallest intended size. Additional samples representing different fit
pad configurations may also be provided at the discretion of the submitter.
MODIFICATIONS
Cosmetic
changes to certified headgear are permissible.
Such changes are generally limited to marking or trimming the headgear
with manufacturer approved paint or tape.
Otherwise, modifications to certified headgear effectively create new
configurations which shall not have the confidence and certification of
Snell/FIA until properly evaluated.
Manufacturers must not place the Snell/FIA certification label in any
modified headgear without express written authorization.
The
Snell Memorial Foundation and FIA strongly recommend that helmet owners not
modify or contract someone else to modify their helmets. Custom paint and
decoration may add appreciably to the helmet weight and any structural
modification may adversely affect a helmet's protective capability. The Snell/FIA certification and, quite
likely, all manufacturer warranties apply to the headgear only in its “as
manufactured” condition.
RANDOM SAMPLE TESTING
In
addition to the certification testing, the Snell/FIA program will routinely
obtain and test samples of previously certified models. These samples will be selected from among
those stocks intended for retail sale to consumers. In this manner, the program will attempt to
ensure that the helmets made available to the public continue to meet the
performance requirements of this Standard.
In
cases in which helmets are provided directly to users and do not pass through a
normal sales distribution system, the program will set up alternative
procedures to monitor certified products.
Specifically, if helmets are provided directly to teams or individuals
for use in events, the program must have access to the helmets for spot
checking and non-destructive evaluation.
CONSTRUCTION
- General
Helmets intended for heads sixty centimeters in
circumference or greater are considered adult headgear and will not be accepted
for certification to this standard.
Children who require headgear in these sizes are urged to wear
appropriate helmets certified to adult standards.
The assembled
helmet shall have smooth external and internal surfaces. Any feature projecting more than 7 mm beyond
the outer surface must readily break away; all other projections on the outer
surface shall be smoothly faired and offer minimal frictional resistance to
tangential impact forces. Rivets and
similar projections into the helmet interior must offer no laceration or
puncture hazard. Restraint clips may be
used at the rear or on the side of the helmet.
If
the absence of any detachable component of the helmet does not prevent its
being worn, then this absence must not compromise either the retention system
or the impact protection. If any part of
the helmet detaches during testing, it must offer no laceration or puncture
hazard nor reduce the coverage of the head.
If
the manufacturer provides add-ons such as visors, face shields and neck
curtains with the helmet, these add-ons must neither lessen the protective
capability of the basic helmet nor create a direct hazard for the wearer.
B. Shell
If
rivets are used, the heads shall not have sharp edges and shall not project
more than 2 mm from the outer or inner surfaces of the helmet shell.
C.
Materials
Materials
used in the manufacture of the helmet should be of durable quality and not be
harmed by exposure to sun, rain, dust, vibration, sweat or products applied to
the skin or hair. Similarly, the
materials should not degrade due to temperature extremes likely to be
encountered in routine storage or transportation.
Materials
which are known to cause skin irritation or are conducive to disease shall not
be used for the parts which contact the skin.
Materials that support the growth of fungi or algae shall not be
used.
D. Finish
All
edges of the helmet shall be smoothed and rounded with no metallic parts or
other rigid projections on the inside of the shell that might injure the
wearer's head in the event of impact.
E.
Retention System
The
retention system shall be designed so as to discourage misuse. That is, of all the ways in which the retention
system might be used, the design use shall be the simplest and quickest to
implement. Helmets shall not be fitted
with "non-essential" features which, if misused, can degrade the
performance. Quick release buckles, if
used, shall not be able to be released inadvertently.
Fabric
chin straps, if used, shall not be secured to the shell by a bolt, pin or rivet
passing through the fabric itself.
Although other alternatives may be proposed, the preferred method of
attachment is that the strap be looped through and sewn about a metal hanger
which can then be secured to the shell by bolt, rivet or other appropriate
means.
F.
Peripheral Vision
The
helmet shall provide peripheral visual clearance as measured using a reference
head form appropriate to the size of the helmet. This peripheral vision includes a horizontal
clearance of at least 210°, an upward clearance of at least 7° and a downward
clearance of at least 30°. However, this
downward clearance makes specific allowance for breath deflectors. These clearances are described in terms of
planes fixed in the reference head forms.
Some
competitive four-wheeled applications may permit helmets with more restricted
visual fields. For such helmets, a
second set of peripheral vision requirements is specified. The minimum horizontal, upward and downward
requirements for this more restricted field are 180°, 5° and 20°
respectively. Helmets satisfying this
visual field requirement but not the broader visual field specified generally
are also subject to additional labeling requirements warning that the headgear
is considered appropriate only for certain uses.
G. Weight
Permissible
helmet weights depend on the smallest head circumference for which the helmet
is intended and whether the helmet is configured to accept a face shield. Headgear shall be weighed in the most massive
configuration possible with accompanying helmet paraphernalia.
|
Maximum Permissible Helmet Weight in Grams versus Helmet Size in
Centimeters |
||||||||||||
|
Smallest Size (centimeters) |
<49 |
49 |
50 |
51 |
52 |
53 |
54 |
55 |
56 |
57 |
58 |
59 |
|
Helmets configured without face shields |
1000 g |
1050 g |
1100 g |
1150 g |
1200 g |
|||||||
|
Helmets configured to accept face shields |
1100 g |
1150 g |
1200 g |
1250 g |
1300 g |
|||||||
LABELING AND
MARKING
Each
helmet shall have durable, visible and legible labeling identifying the
manufacturer, the month and year of manufacture, the model and the size. Labeling shall be uncoded and either in
English or a language common to the area where the helmets are to be
distributed. The headgear shall also be
labeled to the following effect:
1.
No helmet can
protect the wearer against all foreseeable impacts. However, for maximum protection, the helmet
must be of good fit and the retention system must be securely fastened to
retain the helmet. The helmet, when
fitted and fastened, shall not be removed easily.
2.
This helmet is
so constructed that the energy of an impact may be absorbed through its partial
destruction, though damage may not be visible.
If it suffers an impact, it must either be returned to the manufacturer
for inspection or be destroyed and replaced.
3.
The smallest
and largest head circumferences for which the helmet is appropriate in
centimeters.
4.
If the helmet
does not satisfy the broader visual field requirements set for general use the
helmet must be labeled to the following effect: “RESTRICTED VISUAL FIELD – MAY
NOT BE APPROPRIATE FOR SOME ACTIVITIES”
If
any of the helmet components are sensitive to common solvents, adhesives,
paints or cleansers; the helmet must also bear labels to the following effect:
“This helmet can be
seriously damaged by some common substances without visible damage. Apply only the following: (Recommended cleaning agents, paints,
adhesives and the like) as appropriate.”
If
the helmet model was certified according to a special addendum to this
standard, each helmet shall also include the warning labels required by that
addendum.
Each
helmet shall also include one of two Snell/FIA serialized CMH certification
labels. Helmets meeting only the
narrower visual field requirement must include the special Snell/FIA label
signifying that the helmet is intended only for certain activities. Helmets meeting the broader visual field
requirements may include either of the two labels. This certification label
shall be placed either inside or on the outside of the helmet, as appropriate,
in such a way that it cannot be removed intact.
The
registered trademark (certification label) of the Snell Memorial Foundation and
the wording “FIA” may be used by the manufacturer only under license. However, under no circumstances shall the FIA
logo be used. The specifics of licensure
may be obtained from the Snell Memorial Foundation.
MARKING AND
LABELING OF CRITICAL COMPONENTS
If a helmet component may reasonably be replaced
with an inappropriate substitute that might degrade wearer safety and
performance in any of the tests called out in this standard, the manufacturer
must mark those components so that users may avoid the purchase and use of
inappropriate replacement parts. In
particular, face shields on full face helmets must be marked to identify the
manufacturer and the month and year of manufacture.
HEAD FORMS
This
standard invokes four standard head forms for helmet inspection, marking and
testing. The geometry of these head
forms is according to the definitions for the ‘A’, ‘C’, ‘E’ and ‘J’ head forms
described in International Standards Organization (ISO) Draft Standard ISO DIS
6220-1983. The impact mass
specifications for the impact test phase are comparable to those in ECE 22-05
for these same head form designations.
ISO
DIS 6220-1983 includes descriptions for half head forms suitable for guided
fall impact testing or for full head forms such as those used in the positional
stability tests. Figures 1 and 2 depict
the general shapes of the half head form configuration.
The following table lists useful dimensions from
the two references given above.
|
Head Form |
Circumference |
Mass |
Crown to Basic
Plane |
Basic to Reference
Plane |
|
A |
50 cm |
3.100 kg ± 100 g |
113.5 mm |
24.0 mm |
|
C |
52 cm |
3.600 kg ± 100 g |
118.0 mm |
25.0 mm |
|
E |
54 cm |
4.100 kg ± 100 g |
122.0 mm |
26.0 mm |
|
J |
57 cm |
4.700 kg ±
100 g |
130.0 mm |
27.5 mm |
EXTENT
OF PROTECTION
The extent of protection corresponds
to that region of the head for which protection is sought.
There
are a number of planes fixed in the geometry of these head forms as shown in
Figure 1. This description of the extent
of protection uses the ISO definitions of the basic plane, the longitudinal
plane, the transverse plane and the reference plane. Other planes have also been defined strictly
for convenience and clarity.
The
basic plane corresponds to the anatomical plane (
These
planes are all well known entities.
Several other planes, however, have proven useful. The S0 plane is parallel to the
basic plane and lies above it at a distance determined by the size of the head
form. The S3 plane is
parallel to the S0 plane and the basic plane and lies between
them. The S4 plane is also
parallel to these planes and lies below the basic plane.
The
rear plane divides the rear third of the head from the front two thirds. It is parallel to the transverse plane and
lies at a given distance behind the point where the reference plane and
longitudinal planes intersect with the front surface of the head form. The distance from this point, hereafter
called the reference point, is determined by the size of the head form. The fore plane is also parallel to the
transverse plane. It lies behind the
reference point at a distance determined by the size of the head form.
The
extent of protection provided by the helmet must include the entire region above
the S0 plane and forward of the fore plane, the entire region above
the S3 plane and between the fore and rear planes and the entire
region above the S4 plane and behind the rear plane. Figure 2 and the associated table lay out
these additional defined features and show the extent of protection and the
test line.
TESTING
A.
Inspection
Each
helmet will be inspected for the required labels and for compliance with the
general limitations made on structure.
Samples received for certification testing must incorporate all the
critical component labels but other labeling is not necessary for evaluation. Samples received for
The weight and various measurements will be
recorded for comparison with other samples of the same make and model. At least one headgear will be weighed in its
most massive configuration. The weight
limits set for helmets depend on the smallest appropriate head circumference
for which the helmet is intended and on whether the helmet is configured
with, or without, a face shield. Note:
if the helmet is configured for use with a face shield, a face shield must be
supplied and shall be included in the weighing.
|
Maximum Permissible Helmet Weight |
|||
|
|
Smallest size |
Configured without face shield |
Configured with face shield |
|
A |
<49 cm |
1000 grams |
1100 grams |
|
49 cm |
1000 grams |
1100 grams |
|
|
50 cm |
1050 grams |
1150 grams |
|
|
51 cm |
1050 grams |
1150 grams |
|
|
C |
52 cm |
1100 grams |
1200 grams |
|
53 cm |
1100 grams |
1200 grams |
|
|
E |
54 cm |
1150 grams |
1250 grams |
|
55 cm |
1150 grams |
1250 grams |
|
|
56 cm |
1150 grams |
1250 grams |
|
|
J |
57 cm |
1200 grams |
1300 grams |
|
58 cm |
1200 grams |
1300 grams |
|
|
59 cm |
1200 grams |
1300 grams |
|
At the discretion of the technician, additional
helmet assemblies may be required to make this determination with appropriate
levels of confidence.
Some
helmets may incorporate innovations and other features not anticipated by this
Standard but which raise concerns about the safety and effectiveness of the
headgear. These will be referred to
members of the Foundation's Board of Directors and/or authorities at the FIA
for evaluation. Any feature deemed to
reduce the protective capacity of the headgear, whether explicitly mentioned in
this Standard or not, will be a cause for rejection.
B. Head
Forms and Helmet Positioning
The determination of which head forms are
appropriate to a helmet is based on the specified smallest and largest head
circumferences for the helmet. For
samples submitted for certification, this specification must include the
smallest and largest values of head circumference for every possible fit pad
configuration of the helmet. For helmets
received for
The smallest appropriate head form for a particular
helmet is the largest of the four head forms whose circumference is no greater
than the manufacturer’s specified smallest circumference. The largest
appropriate head form is the largest of the four specified head forms whose
circumference is no greater than the manufacturer’s specified largest
circumference.
If any of the test sample helmets is determined
to be too small to accommodate the largest head form identified as appropriate,
the next smaller head form shall be considered the largest appropriate. If any sample is too small for even the
smallest appropriate head form as indicated by the manufacture specification,
the samples shall be rejected for certification.
The following table shows which head forms will
be used in certification testing for various head size specifications. Since the largest head size should never be
smaller than the smallest head size, most of the lower left region of the table
is blank. If the size specification
corresponds to one of the light gray cells, only a single head form will be
necessary and only five helmet samples, configured for the largest head size
specified, are required for testing.
Otherwise, the tests will involve two head forms and seven samples are
required, five configured for the largest head size specified and two
configured for the smallest size
specified.
|
Test Head Forms as Determined by Size Specification |
|||||||||||
|
|
Largest Head Circumference Specified |
||||||||||
|
50 |
51 |
52 |
53 |
54 |
55 |
56 |
57 |
58 |
59 |
||
|
Smallest Specified Size |
<50 |
A |
A |
A,C |
A,C |
A,E |
A,E |
A,E |
A,J |
A,J |
A,J |
|
50 |
A |
A |
A,C |
A,C |
A,E |
A,E |
A,E |
A,J |
A,J |
A,J |
|
|
51 |
|
A |
A,C |
A,C |
A,E |
A,E |
A,E |
A,J |
A,J |
A,J |
|
|
52 |
|
|
C |
C |
C,E |
C,E |
C,E |
C,J |
C,J |
C,J |
|
|
53 |
|
|
|
C |
C,E |
C,E |
C,E |
C,J |
C,J |
C,J |
|
|
54 |
|
|
|
|
E |
E |
E |
E,J |
E,J |
E,J |
|
|
55 |
|
|
|
|
|
E |
E |
E,J |
E,J |
E,J |
|
|
56 |
|
|
|
|
|
|
E |
E,J |
E,J |
E,J |
|
|
57 |
|
|
|
|
|
|
|
J |
J |
J |
|
|
58 |
|
|
|
|
|
|
|
|
J |
J |
|
|
59 |
|
|
|
|
|
|
|
|
|
J |
|
Each
helmet will be positioned on the smallest, largest or any of the intervening
head forms for testing according to the helmet positioning index
specified. If the manufacturer fails to
provide positioning information with certification samples, the helmets will be
positioned according to the best judgment of the authorized technical
personnel. If the helmets meet
certification requirements, the helmet positioning indices will be those used
in all future testing.
These
helmet positioning indices represent distances on the head form measured from
the basic plane along the intersection with the longitudinal plane to the lower
edge of the helmet. Helmet
positioning indices will be assigned for all head form sizes appropriate to the
headgear. Each headgear could
conceivably require four helmet positioning indices, one each for the ‘A’, ‘C’,
‘E’ and ‘J’ head forms
C. Marking
The
helmet is placed upon the largest appropriate ISO head form, positioned
according to the corresponding helmet positioning index and held in place with
an applied force of 50 newtons (11.25 lbs).
If the helmet has a hinged face plate which may be opened to expose the
face or closed to cover the entire face and chin such as in a “flip-up” or
“system” configuration, the face plate shall be closed and latched. The intersections of the shell with the
various defined planes are then traced onto the outer surface of the helmet in
the following manner:
The
level of the S0 plane is marked on that portion of the helmet in
front of the fore plane. The level of
the S3 plane is marked on that portion lying between the fore and
rear planes. The level of the S4
plane is marked on that portion behind the rear plane. Finally, line segments along the fore plane
are marked to join the S0 and S3 planes and, similarly,
line segments along the rear plane are marked to join the S3 and S4
planes.
These
lines enclose the top of the helmet and are considered the boundary of extent
of protection. However, it shall not be
a cause for rejection if parts of this boundary fall below the edge of the
helmet. Instead, a test line shall be
constructed within the extent of protection 40 mm from the closest point on the
boundary as shown in figure 2. This test
line bounds the area over which the helmet must withstand impact and shell
penetration testing.
Generally,
the test line as marked on the largest appropriate head form will include the
entire test area obtained if the helmet were to be marked on a smaller appropriate
head forms. However, at the discretion
of the test technician, this marking may be duplicated on smaller head forms to
determine whether the helmet positioning indices or fit pad configurations
might lower portions of the test line beyond those for the largest head
form. In such a case, the test line will
be the line bounding the union of the test areas determined by this
marking. That is: the helmet must meet all of the requirements
of this Standard in each of the intended configurations.
D. Shell Edge
Lower Limit
Helmets shall be
placed upon the smallest appropriate ISO head form, positioned according to the
corresponding helmet positioning index and held in place with an applied force
of 50 newtons (11.25 lbs). If the helmet
is configured with a moveable face plate, the face plate shall be closed and
latched. The vertical distance from the
basic plane of the head form to the lowest point on the helmet shell shall be
measured at the front and rear in the midsagittal plane and right and left in
the transverse plane. This measurement
shall include edge beading but shall not include any helmet comfort and fit
padding which may protrude below the edges of the helmet shell. This distance
shall not exceed 14.0 cm in front, 9.0 cm on the right and left, or 4.0 cm in
the rear.
E. Peripheral Vision
The clearance for
peripheral vision will be checked by placing the helmet on each appropriate ISO
head form, positioning it according to the corresponding helmet positioning
index and holding it in place with a force of 50 newtons. If additional samples configured with fit
pads have been provided as part of a submission for certification, the
peripheral vision checks will use the configuration appropriate to the head
form. The clearance must include the following solid angles to the front of the
head form:
1. The
upward visual clearance.
2. The
lateral visual clearance.
3. The
downward visual clearance except for the breath deflector allowance.
The
upward visual clearance is the solid angle bounded by the reference plane of
the head form and a second plane tilted up from the reference plane. This angle is 7° for the general
requirements and 5° for the restricted vision requirement. The second plane intersects the reference plane
at two points on the front surface of the head form that are 31 mm to the right
and left of the longitudinal plane as shown in figures 3 and 3b.
The
general requirement for lateral visual clearance is shown in figure 4. It is
the solid angle bounded by the reference plane, the S4 plane and two
more planes that are perpendicular to the reference plane and lie to the right
and left, respectively. These right and
left planes pass through the head forms reference point and form angles of 105°
with the longitudinal plane.
The
restricted visual field requirement is shown in figure 4b. Here, the right and left planes are coplanar
and perpendicular to the longitudinal plane and the reference plane. The right and left planes intersect the front
of the head form at points on the reference plane and 31 mm to the right and
left of the longitudinal plane.
The downward visual clearance is the solid angle
bounded by the basic plane of the head form and a second plane tilted down from
the basic plane and that intersects it at two points on the front surface of
the head form that are 31 mm to the right and left of the longitudinal plane as
shown in figures 5 and 5b. The degree of
downward tilt is 30° for the general requirement and 20° for the
restricted visual field requirement. However, intrusions into these downward
clearances are permitted so long as the intrusions are within the breath
deflector allowance.
The
breath deflector allowance is shown in figure 6. It includes the region that is within 31 mm
to the right and left of the longitudinal plane and that lies below the two
planes that form 45° angles with the longitudinal plane and that intersect it
at the level of the S4 plane.
In order to meet the general visual field
requirements, no part of the helmet
except the face shield may intrude into the solid angles shown in figures 3 and
4 nor into those parts of the solid angle in figure 5 outside the breath
deflector allowance. In order to meet
the restricted visual field requirements, no part of the helmet except the face
shield may intrude into the solid angles shown in figures 3b and 4b not into
those parts of the solid angle in figure 5b outside the breath deflector
allowance. These requirements do not
apply to face shield fixtures such as hold tear-off shields.
F. Performance Testing
The
performance testing subjects helmets to:
•
A
dynamic test of retention system strength.
•
A test
for positional stability.
•
Impact
management tests.
•
Helmet
shell penetration tests.
•
A
removability test
•
And to
chin bar and face shield tests if appropriate.
These
tests are conducted upon helmet samples kept under laboratory ambient
temperature and humidity or that have been conditioned in one of three
environments simulating some of the conditions in which the helmet might
reasonably be expected to be used.
Prior
to conditioning and testing, samples may be exposed to solvents common to motor
sports which have been found to attack and degrade some helmet components.
In
certification testing, the first of the four samples is kept at laboratory
ambient temperature and humidity and allowed to come to equilibrium. It is subjected first to the positional
stability test and then to the impact management and other tests. The second, third and fourth samples are
conditioned hot, cold and wet, and subjected to the dynamic test of the
retention system, the impact management test and the other tests.
The
selection of tests, conditioning and special conditioning is left to the
discretion of the authorized technical personnel. However, for certification testing, each of
the specified tests shall be applied to at least one sample. Furthermore, it is expected that all testing
will be conducted so as to exercise all the likely failure modes of the helmet.
F1. Conditioning for Testing
Test
samples may be kept at laboratory ambient temperature and humidity or may be
conditioned either cold, hot or wet according to the specifications given
below. At the discretion of the
authorized technical personnel and at any point during the testing, a sample
previously kept at ambient may be conditioned cold, hot or wet. However, once a sample has been conditioned
cold, hot or wet, the sample must be maintained in that condition throughout
the rest of the testing.
The
special solvent wipe conditioning described below may be applied to any sample
at the discretion of the authorized technical personnel.
a.
Special Conditioning. Prior to any impact or retention system
testing helmets may first be conditioned with a solvent mix of 50% toluene and
50% isooctane. A cotton cloth or suitable
substitute shall be soaked in the solvent and used as an applicator. The solvent will be applied to the shell
first in an area within 5 mm of the chin strap attachments for not less than
five (5) seconds on each side and then applied to the remainder of the shell
for not less than ten (10) seconds. At
least thirty minutes shall elapse before further conditioning and testing.
b.
Cold. The sample shall be conditioned by being
exposed to a temperature of -20 ±2° C for a period of not less than four (4)
hours, nor more than twenty-four (24) hours.
c.
Heat. The sample shall be
conditioned by being exposed to a temperature of 50 ±2° C for a period of not
less than four (4) hours, nor more than twenty-four (24) hours.
d.
Wet. The sample shall be conditioned
by being continuously sprayed with water at a temperature of 25 ±5° C for a
period of not less than four (4) hours, nor more than twenty-four (24)
hours. This spray shall be directed at
the helmet's external surfaces. The
helmet shall not be subjected to total immersion.
All testing of these
hot, cold and wet helmets shall begin within two (2) minutes from the time of
removal from the conditioning apparatus.
The samples shall be returned to the conditioning apparatus between
tests.
F2.
Positional Stability (Roll-Off)
The test for positional stability
shall only be applied to samples kept at ambient laboratory temperature and
humidity. The helmet shall not have been
subjected to any prior performance testing.
The
helmet shall be tested on the smallest appropriate standard full-face head
form. The head form shall be supported
on a stand so that its vertical axis points downward at an angle of 135° to the
direction of gravity. The head form
shall be oriented face down. The helmet
shall be placed on the head form and adjusted to obtain the best configuration
of the retention system. A non-elastic
strap shall be hooked to the edge of the helmet at the rear centerline and
brought forward so that its free end hangs downward across the top of the helmet. An inertial hammer shall be suspended from
the free end of the strap. This inertial
hammer shall enable a 4.0 kg ±50 g mass to be dropped through a 0.6 m guided
fall in order to deliver an abrupt shock load to the headgear. The shock load will force the helmet to
rotate forward on the head form. The
helmet may be shifted but must remain on the head form.
The
head form shall be repositioned so that it is facing upward but with the
vertical axis still oriented downward at 135° to gravity. The helmet shall be positioned and adjusted
to obtain the best configuration of the retention system. The strap/inertial hammer shall be hooked to
the brow edge of the helmet at the center line so that the strap lies along the
centerline and the hammer is suspended from the top of the helmet. The shock weight shall be dropped through the
0.6 m guided fall delivering an abrupt shock load forcing the helmet to rotate
rearward. The helmet may be shifted but
must remain on the head form.
The
entire portion of the inertial hammer assembly that participates in the loading
of the helmet shall be such that its mass is no more than 5.0 kg including the
4.0 kg shock mass.
F3.
Dynamic Test of Retention System
The
dynamic test of the retention system may be applied to any sample either kept
at ambient temperature and humidity or conditioned hot, cold or wet. This test may be performed before, after, or
between any of the other procedures in the test sequence. However, the retention test shall not be
valid if an integral chin bar has been removed from a full face helmet.
The
helmet shall be placed on the largest appropriate head form in such a manner
that the chin strap may be fastened under a device whose upper end approximates
the contour of the bony structure of the jaw.
The device will then be given a mechanical pre-load followed by a
dynamic loading. The retention system
fails if it cannot support the mechanical loads or if the maximum deflection
during the dynamic load exceeds 30 mm.
The retention system also fails if it cannot be easily and quickly
unfastened after testing.
a.
This chinstrap loading device shall consist of a simulated jaw and
accommodations for the pre-load and dynamic load. The jaw portion shall consist of two metal
bars or rollers, each one 12.7 ±0.5 mm in diameter, separated by 76 ±0.5 mm on
center. The mass of this device shall
not exceed 6.0 kg.
b.
A pre-load shall be applied for at least 60 seconds. This pre-load plus the mass of the chinstrap
loading device shall total 23 kg±500 g.
c.
A 38 kg±500 g mass shall be dropped in a vertical guided fall a distance of 120
mm so as to load the retaining system abruptly; the 38 kg mass and pre-load
mass shall not be additive. In order to
protect the test mechanism, the impact of the 38 kg mass may be cushioned with
a 00-93 durometer rubber pad 150 mm in diameter by 6½ mm thick, or its
equivalent.
F4. Impact
Management Tests
The impact management tests may be
performed on samples kept at ambient temperature and humidity or conditioned
hot, cold or wet. The sample shall not
have been subjected to the shell penetration test beforehand.
These
tests involve a series of controlled impacts in which the helmet is positioned
on a test head form. The helmeted head
form is then dropped in guided falls onto specified test anvils. The impact site and the impact velocity must
meet certain requirements in order for the tests to be valid.
If
the sample is so constructed that it interferes with the test equipment
preventing impacts at sites within the test line, then, at the discretion of
the authorized technical personnel, parts of the helmet may be cut away to
facilitate testing. Every reasonable
effort to minimize such cutting will be made.
However, there shall be no relaxation of the impact levels or of the
test criteria.
Certain
tests shall not be valid when performed on samples that have been cut for
impact testing: the dynamic strength of retention system test of section F3.,
the positional stability test of section F2., the chin bar test of section F5.
and the removability test of section F8.
Special
considerations apply when the helmet is a ‘flip-up’ model, that is: configured
with a chin bar that pivots up and away from the face of the wearer. Whenever possible, the impact tests will be
performed with the chin bar locked in the closed position. In these tests, in addition to all the other
test criteria, the chin bar must not release and ‘flip-up’ inadvertently.
F4.1 Impact
Management Test Equipment
The
test equipment shall consist of at least the following items:
a.
The smallest and largest of the head forms appropriate for the helmet
sample. This head form shall be of
rigid, low resonance metal such as magnesium alloy and shall conform to the
‘A’, ‘C’, ‘E’ or ‘J’ geometries specified in ISO
b.
A ball-arm/collar assembly which is fitted to a socket machined into the base
of the head form. The ball/socket
configuration shall be such that the geometrical center of the ball is located
on the central vertical axis of the head form 12.7 mm above the reference plane
as described in ISO
c.
A head form support assembly rigidly attached to the ball-arm. This support assembly shall be such that it
and consequently the head form may be guided in a vertical drop. The mass of this support assembly shall not
exceed 1.2 kg. The total mass of the
head form plus ball-arm/collar assembly plus head form support assembly shall
be within 100 grams of: 3.1 kg for the ISO A head form, 3.6 kg for the ISO C
head form, 4.1 kg for the ISO E head form and 4.7 kg for the ISO J head form.
d.
A guidance system such that the head form/support assembly is guided in a
vertical drop onto a test anvil. This
guidance system may consist of two or more wires or one or more rails. The head form/support - guidance system -
test anvil alignment shall be such that:
d1. The drop trajectory shall be a straight line
within 3° of vertical and within 5° of the sensitive axis of the uniaxial
accelerometer.
d2. The line parallel to the drop trajectory and
passing through the center of the head form ball-socket shall pass within 5
mm of the center of the test anvil, within 10 mm
of the center of gravity of the head form/support assembly, and within 5 mm of
the sensitive element of the uniaxial accelerometer.
e.
A rigid anvil mount consisting of a solid mass of at least 500 kg. The upper surface of the anvil mount shall
consist of a steel plate with a minimum thickness of 12 mm and a minimum
surface area of 0.10 m2.
f.
Three test anvils: flat, hemispherical and edge.
f1. The flat anvil shall have a minimum
surface area of 0.0127 m2, e.g. 127 mm diameter face. When fixed in position on the anvil mount,
the surface shall be perpendicular to the head form trajectory.
f2. The hemispherical anvil shall have a 48 ±0.5
mm radius.
f3. The edge anvil shall have a striking face 6.3
±0.5 mm wide by at least 180 mm long with a depth
of at least 35 mm. The radius of the edges on the impact face shall
not exceed 0.5 mm. When in position, the striking face shall be
perpendicular to the head form trajectory.
g.
A uniaxial accelerometer. The
acceleration data channel must comply with SAE recommended practice J 211
requirements for channel class 1000 with the exception that the frequency
response need not include the range from dc to 10 hz which may not be
obtainable using certain types of transducers.
h.
A velocity measurement device which will yield the velocity of the head
form/support assembly within the last 40 mm of travel before impact. The velocity measurements must be accurate to
within ±1%.
F4.2 Test
Definitions
a. The impact site refers to the portion of the
helmet struck during an impact test. It
is defined as the point where a line passing through the center of the head
form ball and the center of the anvil intersects the outer surface of the
helmet at the instant the helmet first touches the anvil.
b.
The impact velocity is the velocity of the head form/support assembly as
measured within no more than 3 cm of the first contact between the helmet and
the impact surface.
c.
There are two levels of test: the first is the standard level used to identify
those helmets which definitely meet this standard. It is applied to samples submitted for
certification testing and to those acquired for the Foundation’s random sample
test (RST) program. The second is the
deviation level which is applied to samples acquired for second round RST
procedures, that is: testing of samples of currently certified models for which
previous samples have obtained failing results in RST testing. Failure to meet test criteria at the deviation
levels indicates that the sample definitely does not meet the requirements of
the standard.
F4.3 Test Impacts
Test
impact sites shall be on or above the test line. Rivets, vents and any other helmet feature
within this region shall be valid test sites.
Each impact site will be subjected to a group of one or two impacts
according to the anvil selected for that site.
The
impact site for the first impact within a group is the target for the
successive impacts in the same group.
However, if an impact group is sited closer than 120 mm to any previous
impact group, that later impact shall be declared invalid.
There
is no restriction regarding test anvil selection. The technician may
select either the largest or smallest appropriate head form for any particular
group of impacts. In all cases the
technician may impact any site on the helmet surface on or within the test
lines as drawn for any of the head forms considered appropriate for that
helmet.
|
Test
Impact Velocities |
||
|
Certification |
1st
|
7.75 m/s |
|
2nd
|
6.00
m/s |
|
|
Deviation |
1st |
7.48
m/s |
|
2nd |
5.80
m/s |
|
a. Each site tested against the flat anvil shall be
tested according to the values in the test impact velocity table.
b. Each site tested against the hemispherical anvil
shall be tested according to the values in the test impact velocity table.
c.
Each site tested against the edge anvil shall be tested according to the values
in the test impact velocity table. No
helmet shall be subjected to the second impact for this anvil.
d.
If the impact velocity for any test impact exceeds the velocity specified by
more than 1.5%, that impact shall be declared invalid.
Please
Note: The impacts described above are based on specific velocities and not
prescribed drop heights. To attain the
proper velocity for an impact, it is likely that the drop height will need to
be adjusted to compensate for frictions inherent in most mechanical helmet testing
systems. Height adjustments for these frictions should not account for more
than 10% of the total drop height. Also,
the 1.5% margin allowed for impact velocity reflects the uncertainties expected
even for well maintained drop equipment.
It is expected that drop heights will always be selected to produce, as
closely as possible, the precise impact velocities called out in the standards.
F4.4 Impact
Test Interpretation
The
peak acceleration of the head form shall not exceed 290 G’s for any valid
certification impact or 300 G's for any other valid test impact. The helmet’s protective structures shall not
break apart throughout the testing. If
the authorized technical personnel conclude that fracture of the helmet shell,
impact liner, retention system or other components could reasonably imply an
undue laceration hazard either from the impact surface or from the helmet
itself, the sample shall be considered to have failed. A flip-up configuration tested with the chin
bar closure locked at the outset of a valid impact and which releases inadvertently
as a result of the impact will also be deemed to have failed.
If,
in certification testing, a sample is found to meet all the test criteria but
any two of the impacts were at less than 98% of the impact velocity specified,
the testing for that sample shall be declared inconclusive and must be
repeated. Similarly, if there are two
instances where an impact falls beyond 10 mm from the first impacts in its
group, the testing for the sample shall be declared inconclusive and must be
repeated. Finally, if an invalid impact
produces a peak acceleration exceeding the test criterion, the testing for the
sample shall be declared inconclusive and must be repeated.
The
impact test procedures leave considerable latitude to the helmet tester
regarding site and anvil selection. It
is expected that the tester will orchestrate each standard test series in order
to investigate potential weaknesses and to exercise each likely failure mode
and will conduct deviation level testing to exercise the failure modes identified
previously.
If
at the end of a certification test series, the authorized technical personnel
conclude that the results obtained in valid impacts are not sufficient to
determine whether the helmet model meets the performance requirements of this
standard, additional samples may be conditioned and tested. It is expected that all samples submitted
will meet all the test requirements.
F5. Chin
Bar Tests
There are two tests for facial protection:
F5.a. Chin
Bar Rigidity
At
least one helmet in each certification series shall be tested. The sample shall not have been previously
tested in chin bar impact. The helmet
shall be firmly mounted on a rigid base so that the chin bar faces up and the
reference plane is at 65 ± 5° from horizontal.
A mass of 5 ± .2 kg with a flat striking face of 0.01 m² minimum area
shall be dropped in a guided fall so as to strike the central portion of the
chin bar with an impact velocity of 3.5 ±0.2 m/sec. The maximum downward deflection of the chin
bar must not exceed 60 mm nor any component fail so as to cause a potential
injury to the wearer.
F5.b. Chin
Bar Impact
At
least one helmet in each certification series shall be tested. The sample shall not have previously been
tested in chin bar rigidity, retention strength or in positional
stability. The helmet shall be placed
upon the largest appropriate full face head form and the chin strap shall be
firmly secured beneath the head form’s chin.
Reasonable effort shall be made to position the helmet according to the
correct helmet positioning index (HPI).
The helmet shall then be tested in a guided free fall in the following
manner:
The
helmet shall be placed in a special cradle which can move downward freely along
guide wires or one or more rigid rails delivering its contents to impact
against a flat anvil such as described in paragraph f1. of section F4.1 of
this standard. The helmet shall be
positioned in the cradle in such a manner that the helmet’s longitudinal plane
is within 3º of vertical and the helmet’s Z axis is tilted to 65º ±
3º. The planes and axes of the helmet
coordinate system correspond to those of the appropriate head form when the
helmet is placed on the head form, held in place with a force of 50 newtons
applied to its crown and positioned according to its established helmet
positioning index. If the impact point
will be within 15 mm of the rim, the helmet and head form shall be repositioned
so that the impact point is not less than 15 mm from the rim. Once the helmet and head form have been
positioned in the cradle, the helmet may be secured to the cradle by strapping
with Velcro closures or some comparable mechanism that will release reliably at
the onset of impact.
The cradle with the helmet and head
form shall be dropped along the guides such that the chin bar will strike the
flat anvil. The velocity of the falling
cradle shall be measured in the manner described in paragraph h. of section F4.1 of this standard. The shock acceleration at the design center
of gravity of the head form shall be measured by means of a tri-axial
accelerometer and data recording system meeting the requirements of SAE
J211.
If the impact velocity measurement
is 5.5 m/s or more and the peak magnitude of the recorded acceleration of the
head form is 275 G or less, the sample shall be deemed to meet the test
requirement. If the impact velocity is
less than 5.65 m/s and the peak magnitude of the acceleration exceeds 275 G,
the sample shall be deemed not to meet the test requirement. If the test measurements do not meet one of
these two conditions, the test is inconclusive and must be repeated.
F6. Shell
Penetration Test
The
shell penetration test may be applied to helmets kept at laboratory ambient temperature
and humidity or helmets conditioned hot, cold or wet. At least one helmet
sample shall be tested in shell penetration.
The complete helmet shall be placed on a rigidly mounted head form. The test head form for the penetration test
need not be the standard ISO head form shape used in the impact testing and
helmet marking. It is expected only that
the device used will provide reasonable support for the helmet and conformance
with the interior of the helmet immediately beneath the site of the penetration
test. If the helmet contains a sling or
some other adjustable sizing component, it shall be relaxed to its most
extendable position.
The
penetration test striker shall have a mass of 3 kg ±50 g. The striker shall fall through a height of 3
m ±15 mm. The point of the striker shall
be a cone with an included angle of 60° ±0.5° and an altitude of 38 ±0.38
mm. The striking tip shall have a
hardness of 60 Rockwell (scale C ±3 points) and a radius of 0.5 ± 0.1 mm.
The
test striker may be directed at any site on or above the test line but the
penetration test site must be at least 7.5 cm removed from the center of any
impact test site or any other penetration test site. At the test technician’s discretions, samples
may be tested at more than one site on the shell.
For all penetration tests performed, the test striker must
not penetrate to achieve even momentary contact with the test head form.
F7. Face Shield Penetration Test
If
a face shield is provided, this face shield shall be tested for penetration
resistance in the following manner:
The
face shield shall be tested on the appropriate helmet, correctly deployed
across the facial opening and under laboratory ambient conditions. A soft lead pellet weighing 1 ±0.1 g with a
diameter of 5.5 ±0.1 mm and traveling at a velocity of 500 ±20 km per hour
shall strike the face shield normal to the surface. The face shield shall be tested in at least
three different locations: the center
line and 80 ±5 mm to either side of the center line. The pellet must not penetrate to the interior
of the helmet.
F8. Removability
The
helmet removability test determines whether the helmet can be removed from an
unconscious victim without resorting to any buckles, clasps or other mechanisms
which may be rendered non-functional by impact stresses. The helmet is placed on the largest
appropriate complete ISO head form with all the closures and retention systems
engaged. A technician must remove the
helmet from the head form using simple, common hand tools but without accessing
any of the helmet mechanisms.
The
hand tools for this test are limited to shears, simple edged tools and flat
bladed screw drivers. The operation must
not require more than thirty seconds.
F9. Post-testing Disassembly and Inspection
If
a set of helmets is submitted for and passes certification testing, one or more
the tested samples shall be disassembled and inspected. If any of the helmet samples appear to have
been specially configured to meet test requirements and are not reasonably representative
of an economically viable production helmet, the model shall be rejected. In particular, samples must not be configured
with extra layers of hand cut padding and materials inserted between shell and
liner or applied to the inner surface of the liner. Elements such as these may confer an
advantage in satisfying test requirements but are all too likely to be left out
of production units afterwards.
If an internal projection on the helmet shell
is deemed to present an undue laceration or puncture hazard, the model shall be
rejected. In evaluating these internal
projections, no allowance shall be made for liner thickness.