TM 5-803-11/AFJMAN 32-10139
11-3. Safety Surfaces.
face meets the ASTM F 1292 standard. For instance,
a particular surfacing material may not meet test
Adequate safety surfacing throughout play equip-
criteria for a fall from 2400 mm (96 inches), but will
ment use zones is an essential safety requirement.
meet criteria for a 1800 mm (72-inch) fall. It can
Falls from play equipment represent over 70% of all
then be said that this surfacing material has a 1800
playground equipment-related injuries treated in
mm (72-inch) critical height. The critical height of
hospital emergency rooms. Without appropriate
safety surfacing material used in children's play ar-
safety surfacing, these falls may result in perma-
eas will equal or exceed the highest accessible height
nent head injury or death.
of the equipment provided. The highest accessible
a. Types of Safety Surfacing. A number of safety
height of various types of play equipment is mea-
surfacing materials are available. Each type of
sured from different points. Table 111 describes
safety surfacing has unique advantages and disad-
how the highest accessible height is determined for
vantages. The two major types of safety surfaces are
manufactured play equipment.
synthetic surfacing and loose-fill surfacing. Syn-
d. Manufactured Safety Surfacing. Testing data
thetic surfacing includes tiles that are formed in the
should be obtained from manufacturers of synthetic
factory, or surfacing that is poured in place onsite.
surfaces, chopped tire surfaces, or wood products
Loose-fill surfacing includes organic and inorganic
manufactured as safety surfacing to verify that the
materials, such as sand, gravel, chopped tire, and
surface meets the requirements of ASTM F 1292 for
a headfirst fall from the highest accessible equip-
ment height to be provided.
of reducing severe head injury or death from falls
e. Loose-Fill Surfacing. Loose-fill materials are
from manufactured play equipment. Safety surfaces
often not manufactured specifically as safety surfac-
that meet the requirements of ASTM F 1292 will be
ing. Therefore, test data is often not available from
provided throughout the play equipment use zone.
suppliers. In 1993, the U.S. Army Corps of Engi-
ASTM F 1292 states that the surface must yield
neers commissioned a testing program to develop
both a peak deceleration of no more than 200 g's
recommended material depths for loose-fill sur-
and a Head Injury Criteria (HIC) value of no more
faces. Materials tested include sand, pea gravel,
than 1,000 for a headfirst fall from the highest ac-
and bark mulch. To reproduce required impact-
cessible height of the play equipment. G-force mea-
attenuating performance, the materials must meet
sures the peak deceleration of the head during im-
the requirements in this chapter; the maximum ac-
pact. HIC measures the duration of the impact
cessible height of play equipment must not exceed
during its most sever phase.
2400 mm (96 inches); and the surface must receive
c. Critical Height of Safety Surfacing Materials.
regular maintenance to maintain material depth. A
The performance of safety surfacing is measured
25 mm (l-inch) difference in material depth may
from potential fall heights. The critical height of a
dramatically increase injury potential. Table 112
surfacing material is the maximum height at which
describes the recommended installed material
a headfirst fall from equipment onto the safety sur-
depth for loose-fill surfacing.
Table 11-1. Highest Accessible Equipment Height,