What are the dangers of burning styrofoam

Polystyrene insulation: high risk of fire

Status: 05.11.2014 3:00 p.m. | archive

Polystyrene is Germany's most commonly used insulation material because it is comparatively cheap and easy to process. It now sticks to millions of houses - on an area roughly the size of Hamburg. But styrofoam is made from petroleum and is flammable. Obviously, flame retardants cannot prevent entire facades from going up in flames. This is the result of fire tests carried out by a working group on behalf of the Conference of Building Ministers.

According to this, a simple garbage can fire is enough for a Styrofoam-insulated facade to go up completely in flames. Fire bars made of non-flammable rock wool are intended to prevent a fire from spreading uncontrollably on an insulated facade. But even if all the prescribed measures are correctly implemented, a fire in a garbage can or a motorcycle parked on the house facade can have devastating consequences: According to research by the NDR, the thermal insulation composite system failed so quickly in the test that the fire brigade would not have had enough time to to delete.

Poisonous smoke gases and violent spread of fire through polystyrene

A burning styrofoam insulation leads to the formation of poisonous smoke gases and a violent spread of fire, says Albrecht Broemme. Today's president of the Technical Relief Organization, as head of the Berlin fire brigade, led an operation in 2005 that actually only involved a room fire: "Then the facade started to burn and drove the fire on with a very strong intensity left, right, upstairs and into other apartments. We rescued three dozen people, some of them at the last second, "remembers Broemme. Despite the courageous efforts of the firefighters, two residents died. Since the styrofoam sheets usually contain the toxic flame retardant HBCD, such a fire can also produce highly toxic dioxins, as toxicologists confirm.

NDR made its own fire test

In 2011, NDR television reported on the fire hazard posed by polystyrene. The reason was facade fires, such as in June 2011 in Delmenhorst, where five insulated apartment buildings were burning at the same time. Reporters from 45 minutes then tried in vain to obtain a filming permit for an admission test. These are commissioned and paid for by the manufacturers of the systems. Finally, the reporters commissioned the materials testing institute in Braunschweig to conduct their own fire test. After eight minutes, the fire got out of hand. Toxic smoke spread in the hall. The fire brigade had to extinguish. The German Institute for Structural Engineering denied that the NDR's attempt was meaningful: it did not correspond to the structure required for approval tests. Thermal insulation composite systems made of polystyrene are sufficiently safe.

Fire brigade asked for insulation material to be checked

But a few months later - on May 29, 2012 - it burned particularly hard in the middle of Frankfurt. Within five minutes, a freshly insulated building facade over 20 meters high was on fire. All the windows burst, a cloud of smoke drifted over the city. Luck in misfortune: the building was still uninhabited. After the major fire, the Frankfurt fire brigade chief Reinhard Ries demanded "that this insulation material must be checked immediately". Ries also initiated the detection of facade fires with the participation of polystyrene. The (incomplete) list includes around 40 fires since 2012.

This is how the topic came on the agenda of the building ministers' conference, which established that thermal insulation composite systems (ETICS) with polystyrene insulation materials are "properly certified and safe when implemented in accordance with the approval". Nevertheless, the building ministers set up a working group for further fire tests. This also includes experts from the fire brigades and the test manager of the NDR experiment.

Insulation system fails in a fire test

The first fire test took place in February 2014 in camera. Unlike the previous approval attempts for the systems, which assume a room fire, he simulated a garbage can fire in the base area of ​​an insulated facade. A stack of 200 kilograms of wood, equivalent to a full mixed waste container, served as the fire load. The test should show whether the system can withstand the flames for at least 20 minutes. This protection goal is intended to ensure that the fire brigade has sufficient time. The result was clear: the thermal insulation composite system and fire protection measures failed and burned down without leaving any residue. After eleven minutes, there were the first signs that the base was burning. Two minutes later the ETICS opened and went into full fire. After 22 minutes everything was completely burned.

For a second attempt, the working group had additional security measures installed that were previously not common: including additional fire bars in the plinth area. In addition, these were better glued and also dowelled. So upgraded, the insulation withstood the fire test. The working group recommends that the additional protective measures become mandatory for new buildings. The building ministers' conference is expected to comment on this on November 14 at a press conference in Chemnitz.

It remains to be seen what should be done with the already insulated buildings. "With existing buildings you also have to see the proportionality," says Gerhard Scheuermann, head of the fire tests project group at the conference of building ministers. There are also conservative measures: "For example, you can put rubbish bins away from the facade."

Flammable insulation materials remain a risk

Thermal insulation: ignorance of the risk of fire

In Hamburg, a garbage can fire spread to the attic of an old building within minutes. The rear light shaft had recently been insulated. (10.12.2013) more

But even if new fire protection measures become mandatory in the future - flammable insulation materials remain a risk. Further tests at the Federal Institute for Materials Research have shown that there is also a risk if the protective plaster layer is damaged. This is exactly the case with many buildings whose plaster is getting on in years. This does not necessarily have to be visible damage, hairline cracks due to aging also pose a risk.

That scares people like Brigitte Seibold. In November 2013, the Hamburg resident saw a small garbage can fire in the light shaft of the old building opposite, eating its way up "like a fire elevator". The stairwell immediately filled with poisonous smoke and turned out to be an escape route. Several residents escaped to the rear balconies. It was thanks to the vacant lot next to the house that the fire brigade was able to rescue them with a turntable ladder. "Once you've seen a fire like this spread rapidly upwards and then threaten the whole house, then you look differently at the world," says Seibold.

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NDR 1 Radio MV | 06/15/2017 | 05:00 am