The Clogger Guide to Global Chainsaw Protection Standards

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There is a lot of confusion about the chainsaw protection standards and how they vary around the world.

Type C, Class 1, chainsaw fabric layers, chainspeed, test methods ….

Understanding the global chainsaw protection standards is becoming increasing important as arborists explore work opportunities in different countries and as arborist retailers start shipping outside their home country.

We thought that it was time to put a comprehensive guide to chainsaw protection standards together.

1. The Two Main Global Chainsaw Protection Standards

Broadly speaking there are 2 global standards.

  • European EN381

The Australian/New Zealand standard is almost a direct copy of the EN381, so for the purposes of this paper it will be grouped under that document. The small differences are outlined later.

The Canadian standards are related to F1897 and will be discussed as a subset of that standard.



a. The European standard EN381

This standard has several parts to it covering footwear, legwear, hand and upper body protective garments.

Part 1 outlines the construction of the test rig for performing chainsaw cut tests.

Part 2 outlines the test methods to be performed on leg protectors.

Part 5 gives the requirements for leg protectors, i.e. the coverage areas, general construction details, the performance testing needed and the labeling and marking information required.

The differences between EN381.5 and the Australian/New Zealand standard, AS/NZS4453.3

  1. EN381.5 only allows for trouser type garments incl. leggings, not chaps that buckle at the rear of the leg, whereas AS/NZS4453.3 allows for both types.
  2. EN381.5 includes 3 different classes of chainspeed testing; Class 1 at 20 m/s, Class 2 at 24 m/s and Class 3 at 28 m/s. AS/NZS4453.3 only has one level of chainspeed testing which is 20 m/s.
  3. EN381.5 outlines the coverage areas for three different designs of trousers, Design A, Design B and design C, whereas AS/NZS4453.3 has adopted Design A only with one very minor modification. These designs will be looked at closely later.
Zero Chainsaw Chaps

b. The North American standard ASTM F1897 – 14

This standard outlines the requirements for leg protection, i.e. general requirements for design and how they are made, the protective coverage areas, the performance testing needed, the certification process, the care and maintenance guidelines and the labeling and marking information required.

The test methods for testing to this standard are given in ASTM F1414 – 13.

c. Comparison of the requirements and the test methods for both of these standards.

The requirements and the test methods employed by both standards are given in the table below. While these differences may appear insignificant, the two standards produce completely different results and the meaning of the results are not comparable, consequently there is no direct correlation between them.

EN381ASTM F1897 &
F1414
Various tests
required
Dimensional change
(shrinkage), chainsaw
cut testing, protective
area checking,
attachment strength
of chainsaw pad to
garment
Chainsaw cut
testing
Preconditioning
of test samples
5 times specified
washing and drying
procedure
5 times specified
washing and drying
procedure
Requirements for
dimensional
change
Less than 6% for both
length and width
No requirement
Requirements for
protective area
Trousers Design A:
covers from 20 cm above
crotch to 5 cm above
hem with an extra 5 cm
of protection wrapping
around on the left side
of each leg.

Trousers Design B:
as for Design A but with
an extra 5 cm wrapping
around 5 cm to the right
of the left leg

Trousers Design C:
Front protection
from 20 cm above
the crutch to 5 cm
above the hem with
rear
protection from 5 cm
below the crutch
to 5 cm above the
hem.
Pants/Trousers: a
minimum length
covering from the crutch
to 7.5 cm (3”) above the
hem with an extra
0.524 rad (30°) or
100 mm (4”) wrapping
around to the left of
each leg. (Note that 30°
equates to approx 6 cm
at the top of the thigh.)
Chaps: a minimum
length of 700 mm (28”)
covering from the crutch
to 25 mm (1”) above the
carrier garment.
Minimum width of 350
mm (14”) at the midpoint
of the pad and 250mm
(10”) at the bottom
of the pad.
Requirements for
pad attachment
strength
200N forceNo requirement

The Testing Requirements of the Chainsaw Protection Standards

Chainsaw Safety Demonstration
EN381ASTM F1897
& F1414
Drive unit for test
rig
Electrically
powered motor
with a clutch
and flywheel of
specified inertia
Standard gasoline
powered chainsaw
with standard clutch
mechanism.
Performed onActual garmentsRectangular pads
made up in the
materials intended
to be used.
Calibration pads
are specified as
200mm x 700mm
however actual test
pads are accepted
in varying
dimensions.
Number of tests6 cuts, 3 on each
leg for Design A,
and 2 cuts on
each leg
on both front
and rear for
Design C.
As many as are
required to
determine the
threshold
chainspeed,
usually 24.
Angle and position
of cut tests
All cuts after
preconditioning,
45° in the knee
area with the
chain moving
upwards from left
to right of the leg.
In the centre of
the test pads.
Usually, those
performed are:
6 cuts without
preconditioning
at 45°,
6 cuts without
preconditioning
at 90°,
6 cuts after
preconditioning
at 45°,
and 6 cuts
after preconditioning
at 90°.
Status of power at
point of release
Power releasedPower remains on
Height above pad at
point of release
3mm50mm (2”)
Distance from
point of contact to
centre of drive
sprocket
130mm130mm
Downward force at
point of contact
15N15N
Chain type8mm, 0.325” pitch10mm, 0.375” pitch
Drive sprocket7 tooth7 tooth
Method of fixing of
test specimen
A row of spikes 30mm
apart penetrate the
specimen for a length
of 800mm on the
opposite side of the
specimen from the
drive unit. The
spikes are omitted
for a distance of
60 mm each side
of the contact point.
Masses of 250g
every 100mm
are used to hold
specimen in
place over the
specimen holder.
2 plates 75 mm x
25 mm with centrelines
290 mm apart are
clamped up tight
on to specimen.
Clamps are on the
opposite side of
specimen from drive
unit. No mass is used
to pull pad taut
over the specimen holder.
20 m/s or 24 m/s or
28 m/s
2750 ft/min
Reporting
method
Pass or fail at the
specified chainspeed.
Cut-through is
deemed to be if there
is a cut of greater
than 10mm in
the lining material.
There are two
reporting
methods. The
first
method is to
evaluate a simple
pass/failure at a
specified
chain speed
e.g. 2750 ft/min.
All 24 pads tested
must show no cut-
through at this chain
speed.

The second
determines a
threshold chain
speed or CS50
which is the speed at
which the
probability of cut-
through is 50%.
Cut-through is
deemed to be any
cut in the lining fabric.

Considerations of these comparisons.

  • The European standard reports the results of cut-testing simply as a pass/fail to a minimum level of chainspeed, therefore no indication is given of the margin of safety that exists of a particular garment above that minimum level.  The CS50 determination as reported under F1897 does give a direct comparison of the performance of different garments which is useful.  Bear in mind that this CS50 determination is an additional test procedure that must be requested from Underwriters Laboratory (UL) and does not constitute part of the certification process.  Certification of a garment by UL means that the garment is certified to pass at the minimum level as specified in the standard.
  • The main differences between the two standards, power status, height above test specimen, fixing methods, size of chain and angle of cuts, all mean that there is no correlation between the two.  Simply converting m/s to ft/min mathematically to compare performance should not be contemplated.
  • The European standard cut testing is performed on an actual garment, although the garment is prevented from rotating on the specimen holder by means of the spikes.  The ASTM standard cut tests are performed on test pads which are only representative of the final product.
  • It is noted that there are no tests performed to determine how well the protective pad is held in place in the carrier garment with the ASTM F1897 standard.

The Canadian standard BNQ 1923-450-M91.

This standard was actually withdrawn some years ago but has continued to be used as the main Canadian standard.  As of August 2018, a replacement has been issued, ASTM F3325 – 18.  The test method for BNQ 1923-450-M91 was specified in BNQ 1923-450-M90 which has now been replaced by ASTM F3324 – 18.

Apart from some minor differences F3324 is identical to F1414 so testing performed is interchangeable between standards.

The main differences between the BNQ 1923 standard and ASTM F1897 are:

  1. BNQ 1923 provides for 3 different designs for both chaps and trousers with varying coverage areas.  Category A covers the frontal area from the crutch to 75mm above the hem plus the rear of the leg from the knee to the ankle.  Category B is just the front only from the crutch to 75mm above the hem.  Category C is the frontal area from the crutch to 75mm above the hem plus an area wrapping around to the left of both legs of 100mm.
  2. BNQ 1923 requires a minimum chainspeed of 3000 ft/min when tested according to BNQ 1923-450-M90, compared to F1897 with 2750 ft/min.

The new Canadian standard F3325 gives a lot more detail to the coverage areas specified than its predecessor, e.g. the length of the rear area of the pad for Category A must be 305mm (12”).  The wording resembles F1897 so that the two standards are much more closely aligned.  F3325 adds another category to the possibilities for coverage area, Category D which is a combination of A and C.  It also includes some specification around the placement of straps on chaps.

The Canadian standard, Worksafe BC Schedule 8-A, section 8.21.

This standard has been adapted from the original WCB (Workers Compensation Board) standard PPE 1 – 1997.  At that time there was a test rig commissioned to test to this standard based in BC, which was similar to the test rig described in F1414, but with one notable difference, namely the specimen holder was free to rotate around its axis.  This meant that the chain engaged with fresh protective fabric as it rotated when under test, whereas with F1414 the chain digs deeper into the same place as it is not free to rotate.  This test rig was decommissioned some years ago when the owner/operator died and the rig was sold to a legwear manufacturer.  It is no longer available for public use.

This Worksafe BC standard is similar to BNQ 1923, however it only allows for one design of garment which is the equivalent of Category C.

Unusually, it allows for four different ways of complying with the cut test requirements:

  1. Achieving a threshold chainspeed of 3600 ft/min when tested using the test rig for WCB PPE 1 – 1997
  2. Achieving a threshold chainspeed of 3300 ft/min when tested according to ASTM F1414.
  3. Meeting EN381-5 at the chainspeed level of 24 m/s
  4. Meeting ISO 11393-2 (same as EN381-5) at the chainspeed level of 24 m/s.

It is to be noted that chainsaw operators and companies generally refer to the minimum chainspeed needed to comply as 3600 ft/min.  What is not understood is that this speed has reference to a test method that is no longer available.  The applicable test speed is 3300 ft/min when tested according to F1414.

Conclusion

In summary, there are very significant differences between chainsaw protections standards globally and the results obtained using one test method cannot be translated over to the other

Both test methods are designed to create a benchmark test by which to compare different manufacturer’s product and this they do.  While neither are perfect, both standards are designed to outline the minimum requirements of leg protectors with the object of protecting chainsaw users from horrific accidents.

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