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Becker Acroma UK’s Pyrolac range of fire retardant
paints and lacquers has been developed to meet strict
UK testing standards.
There are no enforced European standards and tests
are different in each country, however the UK’s
testing standards are amongst the highest.
In the UK the testing standards for fire protection
lacquer systems are:
• BS 476 Part 6 Flame Propagation (equivalent
to European B-s3-d2, in UK terminology = Class 0)
• Part 7 Surface Spread of Flame (equivalent
to European test C-s3-d2, in UK terminology = Class
1)
• Under test methods EN ISO 11925-2 ignitability
test and EN13823 single burn ignition (SBI) test.
These tests relate to the use of the system on interior
wooden wall panels, specifically in exit routes. In
the UK, and many other countries, there is no specific
test in other uses, e.g. domestic staircases, doors
(test relates to door construction), furniture etc.
However, lacquer certified to Class 0 or Class 1 on
wood panelling will provide fire protection for other
applications.
Both parts 6 and 7 assess whole system performance
and a pass certificate is awarded based on the specific
components used, including; lacquers (basecoats, stains,
topcoats etc), veneer, adhesive and substrate.
If certification is required for a specific substrate,
or if one of the system components is altered, the
whole system MUST be tested. Without this, the lacquers
can be used but they will be referred to as an uncertified
system, offering a degree of flame resistance / retardancy.
In the UK, and most of Europe, there is no cover-all
certificate for all wood and board constructions.
Test Procedures
BS 476: Part 7 Surface Spread of Flame
Measures surface spread of flame on a test specimen
by subjecting it to impressed irradiation from a large
radiant panel.
First, a naked flame is fired onto the edge of the
panel. After 60 seconds the flame is turned off and
the time taken for the flames to be extinguished by
the panel is assessed. With PyroLac this is immediate.
(See PyroLac PrO Test Results page.)
Throughout the experiment the flamed edge is held
against a large radiant panel, which supplies a constant
source of heat. The panel is then assessed for a total
of ten minutes to see how far the flames spread along
the panel.
To meet the Class 1 test the maximum spread of flame
is 165mm in the first 1.5 minutes and a maximum of
165mm during the total 10 minute test.
PyroLac test results were as follows across a range
of samples
• Pyrolac One: 74mm average after 1.5 minutes
& 10 minutes
• Pyrolac Pro: 60mm average after 1.5 minutes
& 10 minutes
BOTH WELL WITHIN THE STANDARD
BS476: Part 6 Flame Propagation
A product must first pass BS476 Part 7 to Class 1
to be eligible for testing under BS476 Part 6. There
is no guarantee that a Class 0 pass will occur.
In testing, the products are placed under intense
conditions to simulate a severe fire situation. In
the BS 476: Part 6 fire propagation box, the temperature
rises to about 250C when calibrating it with a non
combustible board.
There are three stages to the test:
• Stage 1 (s1) – the temperature is recorded
every 30 seconds for 3 minutes.
• Stage 2 (s2) – the temperature is recorded
every minute until 10 minutes.
• Stage 3 (s3) – temperature is recorded
every 2 minutes until 20 minutes.
The Sub Index of Performance is calculated after
each stage and then added together to give the Total
Index of Performance (S). To give a Class 0 result,
s1<6 and S<12 are required.
The results below show the performance of PyroLac
Pr0 in the Part 6 tests.
Sub Index s1 = 2.54 Sub Index s2 = 2.97 Sub Index
s3 = 1.95
Total Index of Performance S = 7.46
THIS IS WELL WITHIN THE REQUIREMENTS OF THE TEST
For further information and advice on the EU and
UK standards, please contact us.
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