Surface Spread of Flame.

[Tom Sutton]

“It is impossible for any self-contained or portable structure to fully comply with Class 0 fire regulations due to the nature of the classification.  Class 0 should only properly be applied to lining materials when used as an integral part of a buildings structure.  

Class 1 indicates a good performance in terms of surface spread of flame. Class 0 has the same requirement for surface spread of flame, but in addition also has a requirement to limit heat release.
 
Design and material choice for this project has been undertaken with this in mind, all materials specified are of the highest practicable fire rating and the design has specifically avoided the use of any materials that represent an undue risk.”

Would anybody disagree with the above statement if so where and why?

[wee brian]

It doesnt make sense. what are you getting at?

[Tom Sutton]

It doesnt make sense. what are you getting at?

Can a self-contained or portable structure meet a class O standard or does it only meet that standard when it is lining fixed to a wall in a building. The second paragraph, is this a reasonable description of class 1 and class O.

[kurnal]

TW
In making your statements have you had regard to appendix E and Appendix A of the ADB. Theres also some information in B2 as well.

I dont really understand your statements about class O only applying to lining materials - you are  somewhat undermined when brickwork and blockwork are cited as class O in table A8, as these are often true elements of structure.  

Besides the European standards are taking over and its all getting academic.

[Tom Sutton]

I apologise I should have been clearer with my posting, also I have edited the first posting.

I received a question from a manufacturer of point of sale displays, in duty free areas of airports because the airport had stated the displays should meet a Class O standard. I explained that Class O originated from the Building Regulations and referred to the spread of flame characteristics of elements of structure (Walls and Ceilings) in circulation areas. It could not be applied to portable displays as I would consider them as fittings and furnishings. I gave him some references and he did some research.

He now has got back to me and wishes to include, the above passage, on any quotation / documentation where a client requests ‘Class 0’ compliance in the hope of allowing common sense to prevail if the above statement is correct.

There is obvious confusion, both Wee Brian and Kurnal proves that, so I would suggest he should revises the wording to make it clearer and not just give facts for the reader to work out the meaning. I take Kurnal’s point about the linings but the facts are not totally incorrect and with some modification I feel it would be acceptable.

[Mr. P]

It's not just the display units, but the materials on/in them.  Is he controlling those too?

[kurnal]

Thanks TW I see where you are coming from now.
Its a real problem, trying to do business in this arena of standard clauses and prescriptive conditions imposed by landlords without any understanding of why  they are imposed.

Clearly within the duty free retail area any fire loading imposed by a plastic/ paper/cardboard sales display is going to be insignificant when compared to the thousand or so litres of flammable liquids on the shelves along with the aerosols and all their associated packaging.

In an escape route or mall it may be a different matter. But trying to make them see that is going to be a problem.
And any explanation such as the one you propose is only going to be of use if the facilities manager understands it. Which if he does he probably wouldn't be imposing such a general condition in the first place.

Your contact has two options really. Manufacture the display to meet the most stringent of conditions (The Scottish guides  are an ideal source of standards which they present as benchmarks) so it can meet or surpass anybodies standards, or to use a specific risk assessment in each location. If the display is not increasing the overall fire load within an area, and its in a retail unit then whats the problem?

[John Webb]

BAA had work done on the fire behaviour of duty-free goods shops 10 years ago and the efficacy of standard sprinkler systems to cope with a fire in such shops. I do not know to what degree they've made the results public, however.
This work may be relevant in any risk assessment of these point of sale displays - it is unlikely that they will make a significant contribution to fire load or fire spread if sprinklers are present.

[Tom Sutton]

And any explanation such as the one you propose is only going to be of use if the facilities manager understands it. Which if he does he probably wouldn't be imposing such a general condition in the first place.

I agree but he is just trying to pre-empt future similar demands and knows the chances are slim. The good thing is with his research he now has a reasonable understanding of the situation and can deal with future demands more easily.

[Fishy]

Yes - I would disagree, I'm afraid.  It's perfectly possible to test a material of the sort used in point-of-sale displays (note: not "structure" - BSA 476 parts 6 and 7 do not relate to structures - only materials) and get a Class '0' rating.  I used to work in a Lab. where tests on these sorts of materials were a matter of routine.

BAA are not bound to limit their requirements to those in the ADB.  They are perfectly at liberty to use the performance classifications therein to support their own, additional requirements if they wish.  If your client chose not to comply, he would probably be in breach of contract.

BAA are one of the most knowledgeable 'buyers' of fire safety that I know of - they employ their own Fire Safety Engineers and Managers who have developed their specifications.  I'd be reasonably confident that they knew exactly what they were asking for, and that it was achievable, when they put this spec. together.

“It is impossible for any self-contained or portable structure to fully comply with Class 0 fire regulations due to the nature of the classification.  Class 0 should only properly be applied to lining materials when used as an integral part of a buildings structure.  

Class 1 indicates a good performance in terms of surface spread of flame. Class 0 has the same requirement for surface spread of flame, but in addition also has a requirement to limit heat release.
 
Design and material choice for this project has been undertaken with this in mind, all materials specified are of the highest practicable fire rating and the design has specifically avoided the use of any materials that represent an undue risk.”

Would anybody disagree with the above statement if so where and why?

[kurnal]

Yes I agree Fishy that any landlord can set whatever rules they like. But prescription is something I loathe in any scenario or walk of life. Its what jobs worths thrive on. And generally these rules are set just for others to comply with. In the same way as Crown Property is exempt  from so many of the rules that shackle the rest of us.
I dont think that the BAA have much interest in the nitty gritty of fire safety at  regional airports  do they? I dont know - but I dont see much evidence of it if they do.

[wee brian]

Point to note - you can get class o two ways, Surface spread (class one) + fire prop. or any non-combustible material.

So Class O neednt be a lining material, althoughthats really what it was meant to be for. You can get some quite nasty stuff clasified as class O if you know what you are doing.

[Tom Sutton]

Your first point wee brian was raised earlier in the discussion by Kurnal your second I agree with if I remember correctly polystyrene ceiling tiles disappear so fast that under test they meet the Class O criteria.

Fishy As I understand Class O is defined only in Building Regs and does nor appear in any BSS - check out ADB vol 2 Page 120 Para 13 - so I would reason that outside the building regs it does not exist. Furniture and Fittings are not controlled by Building Regs check out ADB vol 2 page 63 B2 iv unless you consider portable point-of-sale displays are not furniture and fittings?

[John Webb]

I've never been closely involved with surface spread of flame tests, but I'm fairly certain Class 0 is defined in the BS476 series if only to cover something that is better than the behaviour of a class 1 material.
Fire Research carried out full-scale tests some thirty+ years ago to compare corridors lined with different materials as graded by the BS476 test. There was general agreement between the way fire spread in the full-size fires to their rating by BS476.
By the way, never use 3mm ordinary hardboard in a corridor - it's fatal for fire spread - we had 40ft flames coming out of the end of the corridor!

[Tom Sutton]

I've never been closely involved with surface spread of flame tests, but I'm fairly certain Class 0 is defined in the BS476 series if only to cover something that is better than the behaviour of a class 1 material.

John I think ADB vol 2 Page 120 Para 13 would disagree with you.

However I think the important point is when ever deciding the desirable fire characteristics of a item, a risk assessment should be carried out as suggested by Kurnal, to determine is a standard necessary and if it is, the most appropriate standard for it.

When dealing with elements of structure spread of flame is important because walls and ceiling stretch from one end of the building to the other and you do not want a fire spreading at a high rate of knots, for a portable display stretching a few metres is it so important. Maybe some degree of fire retardancy is more appropriate, flame, cigarette or ignitability test would be better?

What I am suggesting before anybody specifies a standards is it the most appropriate standard for the situation.