Key
Definitions:
Arc
Rating:
A term used to indicate the protection factor of a garment.
With rainwear, it will always be equal to the ATPV.
Arc
Thermal Performance Value (ATPV):
The incident energy on a material that results in sufficient
heat transfer through the material to cause the onset
of a second-degree burn on human tissue.
Breakopen
Threshold (EBT) or Breakopen Threshold Above Stoll (EBTAS):
The energy needed to cause the material to breakopen.
Calorie:
The energy required to raise 1 gram of water one degree
C.
Heat
Attenuation Factor (HAF):
The percent of energy blocked by the material.
Stoll
Curve:
Curve used to predict the onset of a second-degree burn
on human tissue.
OSHA
1910.269 Requirement:
The Employer shall not provide rainwear or clothing that
will further the extent of an injury. Example: Melting
and dripping rainwear can melt onto the worker’s
skin and cause a burn that would not have been there otherwise.
The melting burn furthered the extent of the injury.
Performance
Requirements:
Requirements shall be met initially as manufactured as
well as after five cleanings.
Leak
Resistance:
Material must withstand water pressure of 30 psig without
leaking. The seams of the rainwear must not exhibit any
evidence of leakage when exposed to 3 psig for (2) two
minutes.
Tear
Resistance:
Material shall exhibit trapezoidal tear resistance of
6 lbs. In the warp and 6 lbs in the fill direction.
Flame
Resistance:
Material shall be flame retardant per ASTM D6413 with
maximum 2 second flame out and not more than 6”
char length.
Arc
Thermal Performance:
Material shall be tested in accordance with ASTM F1959
with 8 kA arc current, 12” gap, 12” distance,
stainless steel electrodes to determine the following
information:
·
Arc Rating – determine and report value; no minimum
value established for conformance.
· Heat Attenuation Factor – determine and
report value; no minimum value established for conformance
· EBT or EBTAS – determine and report value;
minimum value established at 5 cal/cm2.
· Melting/Dripping – material can show NO
evidence of melting or dripping at an exposure at least
equal to twice the Arc Rating.
· Material response characteristics shall be reported
for two typical exposures at least equal to the Arc Rating
and two typical exposures at least two times the Arc Rating.
Characteristics are: Afterflame time, breakopen, charring,
dripping, electric arc ignition, embrittlement, melting
and shrinkage.
