How often do you check your smoke alarm?

Wow, that’s a very safe set-up you have there!

I don’t think the Fire Brigade would have been all that bothered because I’m sure they’d prefer to discover it was a false alarm than turn up too late to save people’s lives due to alarms which don’t work properly or don’t work at all. I live in a rented flat so have no control over which brand of alarms are fitted, but must have woken the neighbours up at 1 am one night when smoke from a very small amount of over-heated hot cooking oil set the whole lot off! If nothing else, at least it proved their efficiency. They’re all connected to the electricity supply, so no danger of being switched off or batteries running out, so I would strongly recommend that other people get similar alarms. You should still test them fairly regularly though just in case there’s a malfunction somewhere.

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I agree, Lauren. It would be good if BSI provided test scores for smoke alarms, like Which? product reviews do.

When I moved home I was disappointed how quiet the existing mains-powered interlinked smoke alarms were, so I replaced them with ones that might wake me up if there was a fire. I also bought some battery-operated ‘Best Buy’ smoke alarms and they are loud. That is important if you follow advice and close all doors at night.

The standard is European, implemented in the UK (as most are) by BSI as BS EN 14604. Standards are automatically reviewed at no more than 5 year intervals. There is a European Draft that closed to comments last year which I imagine will lead to a revised standard when all bodies have considered the responses.

The current standard requires an alarm to sound, under a variety of conditions, when a particular aerosol density has been reached in a smoke tunnel it seems. Various sources of fire are used in the tests.

@ldeitz, I’d be interested to see the results of your tests that suggest tardiness, and the relevant part of the standard that you feel needs addressing. I had a quick look through the standard, but could not see a reference to a time to respond, only reference to a “smoke” (aerosol) density threshold at which the alarm should initiate. May have missed it. I assume your testing is done in accordance with the standard.

The draft for comment does give a maximum response time to slowly developing fires.

I have several times commented on how useful it would be if Which? were active in the BSI and directly involved in the consideration of standards. This is a good example perhaps of where their experience would be of value.

I would be interested to know if smoke and carbon monoxide alarms that perform poorly in Which? tests are non-compliant with the standards or if the standards should be more demanding.

This standard provides the minimum acceptable basis on which all compliant products should operate, under a variety of conditions and fire types. If it reliably detects a fire, gives an adequately audible signal, works in humid or high temperature conditions, gives repeatable results in testing, withstands battery reversal, deals with false information…..in other words if it passes a range of stringent tests (20 samples are used) then it will be deemed to comply. The basic performance criteria is then whether they reliably detect a likely fire. If they do, they pass, if they don’t, they fail.

It seems to me that if you reduce the time to alarm, that suggests a lower aerosol threshold initiates the device which suggests it is more likely to give a false alarm. You could rate then on loudness of the alarm, robustness of design, battery life perhaps, whether it contains an escape light, price for example but these are not for a standards institution to comment on.

I take your point about false alarms, Malcolm. Many have a mute button to silence them temporarily, which seems a better option than making the alarm less sensitive.

I am very glad that we have standards – as I have said on many occasions – but if products were given ratings or even an overall rating, that would encourage improvement. Not everyone can afford to pay a subscription to Which?

Several years ago I bought a new smoke alarm with escape light to replace an old one that did not have a very good light. I assumed that the small lamp was a high intensity LED. No – it was a smaller bulb than the old one, and was far less effective. I think I gave the details in an old Conversation.

Hi Malcolm – the full results are in the September edition of the magazine, but you can see the ‘Don’t Buy’ results and overall results of the testing here: http://www.which.co.uk/news/2017/08/unsafe-smoke-alarm-revealed-by-new-which-tests/

As far as I can see from the EN standard, the tests measure the threshold value of the aerosol density at which the alarm is triggered – in other words, the smoke density when the alarm goes off. This is measured under specified conditions in a smoke tunnel. So it is not the time it takes to alarm to a given smoke density, but to the smoke density at which the alarm responds. The alarm must trigger within a specified range of smoke densities – clause 5.5.3. That is my understanding after a quick scan but perhaps someone will correct me if I’m wrong.

When testing products it is important to do it precisely to the laid down test regime to achieve meaningful results; they have been thought through and developed over many years. If the test regime used is different then results are not comparable.

Were the Which? tests conducted exactly in accordance with BSEN 14604? Were all the products certified to the BSEN (they should carry a kitemark or the equivalent as well as the standard number) or did they simply claim compliance. If the latter, then it would be interesting to check whether the claim is met by testing exactly to the standard. If they fail then they may well be accused of misrepresentation.

Years ago, a Which? report alerted me to the fact that I had a smoke alarm that performed poorly in the Which? tests. I followed the advice and contacted the manufacturer and was send a replacement cover with more holes to allow smoke to enter. As simple as that.

Smoke alarm batteries are sometimes removed and used for other purposes or because of nuisance alarms. A very good feature that I have seen in some alarms is a device to prevent the alarm being replaced on its base without a battery. It would be good to see more manufacturers copy safety features from others.

I would like to see simple battery clips phased out because have never been reliable, in my opinion. There are other better alternatives. An increasing number of smoke and carbon monoxide alarms have non-replaceable batteries. That’s certainly sensible in the case of carbon monoxide alarms, where the sensor has a limited life. I am not convinced it is necessary with ionisation smoke alarms. I have one that is 37 years old and it still work fine. It was pensioned off because the plastic had gone yellow.

The cover would need to be designed to allow the appropriate aerosol density to trigger the alarm. That seems to be the BSEN criterion. Otherwise it would not have passed the standard. Maybe it never did?

Relying on compliance rather than independent testing of products is always going to be second best, in my opinion. I wonder what system is in place to check that smoke detectors marked as compliant actually meet the standards required by law. It is good that Which? does pick up safety issues in product testing but they do not test all products.

For a product to carry the national mark or equivalent – Kitemark in the case of BSI – they must have been independently tested by an approved national laboratory. For a product to be described as complying with a standard, and to carry a CE mark if applicable, it must have full documentary evidence to show that it has been tested in complete accordance with the appropriate standard. It is illegal to market products in the UK and Europe if they do not. BSI et all cannot stop cheats. That is the job of others to catch and prosecute – Trading Standards for example.

I understand the present system but I think it could be improved. Anyway, let’s get back on topic.

This seems very much on topic. “But we’re so worried about the safety implications of this smoke alarm failing our tests that we’re calling on Devolo to remove it from sale while it investigates. We have passed our findings on to Trading Standards.”

i

That’s thanks to the efforts of Which? and not thanks to the system we have in place to ensure that products are safe. Thankfully, everyone will benefit, assuming action is taken, and not just subscribers.

We do not know what tests Which? carried out yet, so do not know if the device failed to meet the safety standard or not. This all needs clarifying before we condemn any system, but I don’t quite know what “system” you refer to. There is a clear system for testing and marking products, but this can be circumvented by cheating. The loss of protection from Trading Standards seems a good place to start to tackle that..

I appreciate that we need clarification. One of my greatest concerns is that the system of setting minimum standards fails to promote improvement, as I said earlier. At least cars are subjected to NCAP safety ratings, food premises are given food hygiene ratings, and so on. I would hope that better businesses would support this.

Meanwhile back on topic, we are left with some smoke detectors being better than others and the general public may not know which to choose unless they are a Which? subscriber. 🙁
At least there was a Which? press release and the topic has been covered in the news: http://www.bbc.co.uk/news/uk-41033313

There are reviews of products online available to the public. Should all Which? reviews be made public free of charge? I don’t see quite how you get round this.

A “minimum” standard does not mean it is defective in its aspirations. it simply says your product must show it meets all these conditions for it to be allowed onto the market. It must do the job for which it is intended. There is absolutely nothing to stop manufacturers exceeding the requirements of the standard. The job of a smoke alarm is to sound a warning as soon as the aerosol reaches a particular level. There seems no point in it doing it at a lower level, presumably because of false alarms. So when you say “some smoke detectors are better than others” they should all detect possible fire equally well. so do you mean they have more features?

The Which? press release includes “An investigation by the consumer group found some alarms could take twice as long to sound as others, with one brand failing to go off at all – despite having BSI Kitemark certification.”. As the standard referred to by the Kitemark appears not to use time to sound, but aeorosol density at which to sound, I’d like to understand better how Which? did their testing and how the results are compatible with the standard’s requirements. As I said earlier, if a product that is Kitemarked fails the BSEN testing, then that is a problem to take up with BSI as it could lead to a licence being withdrawn from the manufacturer. However, we should know how many samples have been tested; the BSEN requires 20, that should all perform within stated parameters. It is possible to have a defective product sample of course but that should be a very rare occurrence..

I would like to see Which? product tests of safety devices such as smoke detectors freely available. It might encourage more subscribers. I don’t know, but it seems socially responsible to me.

If smoke detectors have widely different response times then there can be little doubt that there is a problem. It could be that the tests have not been carried out under the same conditions, the products are not compliant or the standards need updating. Fire can spread very rapidly in the home, as the fire services frequently point out.

Sample number is, I believe, a weakness in Which? testing and probably always has been. I was trained (and trained others) that it is important to specify sample size when writing reports. On the other hand, if any smoke detector underperforms, that is a good reason to investigate further.

We might as well wait to find out more. I wonder what happened about the underperforming carbon monoxide alarms that Which? discovered on sale online. That was months ago.

Could the issue be the consequence of private companies involved on various BSI standard review boards who have a conflict of interest between their own products and having influence over how standards are formed, are revised and implemented?

This is a list of those on the BSI committee John. However, BSI are only one participant in developing and reviewing this standard. Other standards bodies internationally are involved and will consider and implement changes.
Committee members BSI FSH/12/2

Expert – CEN/TC 72/WG 12 and ISO/TC 21/SC 3/WG 8 + 24
UK Expert – CEN/TC 72/WG 14
Expert – CEN/TC 72/WG 12 (EN 54-31)
Fire and Security Association
Chief Fire Officers Association
Committee Chair
Committee Secretary
UL International (UK) Ltd
B R E – Building Research Establishment
National Landlords Association
UK Expert – CEN/TC 72/WG 16
F I A – Fire Industry Association
UK Expert – CEN/TC 72/WG 18
Action on Hearing Loss
Convenor CEN/TC 72/WG 10
UK Expert – CEN/TC 72/WG 6
Expert – ISO/TC 21/SC 3/WG 24
Convenor – CEN/TC 72/WG 4 and WG 20
British Fire Consortium.

No need for a selfie-stick to test smoke alarms that are out of reach. Just use a plastic hand on a stick:

Source: BBC News http://www.bbc.co.uk/news/uk-wales-23043144

I suspect that Chubb and BG alarms might be manufactured by another company, as happens with other products. Looking at an unused Kidde smoke alarm, the carton says custom assembled in China. 🙁

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It’s no secret. Sprue is mentioned on the homepage of the FireAngel website and on product leaflets. I think FA must have a contract with the fire services because they are often fitted free following a home inspection. I would have thought we could have managed to make smoke detectors in the UK.

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To comply with the European safety standard BS EN 14604 smoke alarms must pass stringent tests under a range of circumstances.

I don’t understand how opening the oven door would set off a heat detector in the hall. The reason for fitting heat detectors is to avoid nuisance operation caused by cooking smoke, steam, etc.

Could be smokey fumes from the oven contents that could equally be a fire – just like your toaster can set the alarm off.

I have not seen a heat alarm set off by cooking. I have always been a little unsure about whether pressing the test button really means that smoke detectors would work in emergency.

I don’t have a toaster because I do not like toast. Visitors are welcome to use the grill.

I have asked if the tests are conducted to the BSEN standard requirements. Until Which? tell exactly how they conduct their tests, they may not be. The BSEN measures at what smoke density an alarm is triggered. The Which? results are based on how long it takes an alarm to sound in (as yet) unspecified smoke conditions. On the face of it these are not the same. I’ll wait for Which? to explain.

Thanks very much for the update, Malcolm. I agree that Which? should work with BSI, particularly over safety issues. I don’t think Which? has claimed that the alarm in question has failed any of the tests covered by the official standard, just found that it does not perform as well as other models in its own tests.

I’d like to see Which?’s explanation of their test regime and if it differs from the BSEN before commenting, wavechange.

Let’s help we are kept well informed. It is encouraging that BSI has issued a press release so promptly.

I don’t think so. My suggestion is to replace the batteries regularly and I use the removed batteries in other products that take the same type of battery. Annual battery replacement should mean that you don’t hear annoying bleeps when the house cools down overnight.

OK – I normally buy 10 year battery models – and in my experience they last between 5 and 8 years. I did wonder about just replacing them every 2 years.

Carbon monoxide alarms should be replaced by the date recommended because the sensor used has a limited life.

Smoke alarms are supposed to be replaced by the expiry date too, but I have a 1980 Black & Decker smoke alarm that still works fine. It is taken into the garage when I am working on DIY projects, and I bring it into the house afterwards because the advice is not to have them in garages. If I leave it on a kitchen worktop it goes off when I use the grill.

That’s a good point, David. There is little point in having alarms if you cannot hear them.

The advice from Which? is to replace smoke alarms every ten years. It is in one of the articles on this page: http://www.which.co.uk/reviews/smoke-alarms/article/guides The ones I bought most recently say to replace after five years. 🙁

I suggest contacting the company, Jacqueline. The company that makes them is Sprue and the contact details will be in the leaflet or on the web. That would make them aware of the problem and hopefully you would be sent replacements even if they were supplied by the Fire Service.

Edit: A problem with faulty batteries in FireAngel ST-620 and ST-622 smoke alarms was reported last year: http://www.thisismoney.co.uk/money/news/article-3554501/Top-British-smoke-alarm-manufacturer-admits-90-000-popular-devices-faulty.html

We have not managed to educate most of the public to test their smoke alarms frequently enough, so I question whether we can expect them to investigate which ones to buy. For me, the focus should be on best standards and ensuring that substandard or counterfeit products are dealt with promptly.

There is no evidence that Kitemarked smoke alarms are not fit for purpose. Until we understand Which?’s tests I suggest we cannot assess their validity.

The sensitivity of alarms can be reviewed by the relevant committee but I hope we will see a proper response by BSI regarding the concerns raised by Which?

Did you mean a response from BSI to the concerns raised by Which?

This is clearly an area that requires a good deal of expertise in setting the limits that sensible domestic smoke alarms can meet in practice. BSI have already responded to Which? and invited them to discuss their concerns. https://www.bsigroup.com/en-GB/about-bsi/media-centre/press-releases/2017/august/BSI-response-to-Which-article-on-smoke-alarms/ I would be interested to compare the expertise that formed the basis of the Which? report with that of the BSI (and other international) committees.

That is an acknowledgement of the concerns of Which? and certainly not a useful response. Neither organisation has informed us of whether any discussions have taken place. On the basis that there is criticism of products of sale to the general public, I suggest that it is incumbent on BSI to keep us informed.

It is a constructive response from BSI inviting Which? to discuss their concerns with them. I understand this is being arranged.This could have been done before publication to give BSI the opportunity for input. I don’t know why, when standards are so important, Which? haven’t been more proactive in working directly with BSI in the past.

Which? is effectively doing no more than questioning the range, set by the international standard, within which smoke alarms must sound. The experts involved will need to decide whether closer limits are practical and, if so, what they could be. However the limits are set, some alarms will always sound later than others. Detecting aerosols is not detecting a fire directly, but the likelihood of one developing; the practical upper limit that can be set will no doubt be related to the probability of a developing fire.

Who is the “us” that BSI should keep informed, and how? I would have thought that if Which? do play a proper part in standards development with BSI, they could keep us informed (Which? Members?). I’d hope they would also work with other BEUC members in this, as standards are international, not a national. Whatever is discussed between Which? and BSI will need to go to the international committee.

Sadly, we don’t know the remit and priorities of Which? but they don’t claim to work on standards development. My observation is that Which? identifies problems and alerts the relevant organisations, BSI in this case.

If Which? makes a public statement “We don’t think this is good enough“.
on BSI’s comment “‘The standard covers ionisation and optical alarms, and the test fires ensure that whichever type is used, the alarm provides adequate warning when there is a real fire.’ then I’d like to see it supported with properly-researched proposals on how practical improvements can be made. To do this, it would be very sensible to discuss the issue with the experts on the committee at BSI before publication, to see why the standard is framed in the current way. It may be there are good reasons for its present structure, it may be that improvements are being made, or it may be that improvements could be made.

Working with organisations is better than undermining them.

For reference, this is the relevant BSI Committee FSH/12/2:
Expert – CEN/TC 72/WG 12 and ISO/TC 21/SC 3/WG 8 + 24
Expert – CEN/TC 72/WG 12 (EN 54-31)
Fire and Security Association
UK Expert – CEN/TC 72/WG 14
Chief Fire Officers Association
Committee Chair
Committee Secretary
UL International (UK) Ltd
B R E – Building Research Establishment
National Landlords Association
UK Expert – CEN/TC 72/WG 16
F I A – Fire Industry Association
UK Expert – CEN/TC 72/WG 18
Action on Hearing Loss
Convenor CEN/TC 72/WG 10
UK Expert – CEN/TC 72/WG 6
Expert – ISO/TC 21/SC 3/WG 24
Convenor – CEN/TC 72/WG 4 and WG 20
British Fire Consortium

You have already mentioned that further up the page, Malcolm.

I have little confidence in an organisation that is responsible for standards and makes them available online but not to the general public. I also believe that BSI should be more independent from business and certainly not run as one. This has been my view since before Which? Convo existed.

Let BSI respond properly to the concerns of Which? and in a timely fashion and I will have more confidence in the organisation.

If Which|? were more proactive with BSI, I’d also be happier. I am hopeful that is now changing.

BSI is a business – it sells testing as well as standards and providing support and consultancy to all kinds of organisations, in both the public and private sector, worldwide.
“About BSI

BSI is the business standards company that helps organizations all over the world make excellence a habit. For more than a century we have been challenging mediocrity and complacency to help embed excellence into the way people and products work. That means showing businesses how to improve performance, reduce risk and achieve sustainable growth. As a global leader in helping organizations improve, our clients range from high profile brands to small, local companies in 182 countries worldwide.”

Which is a business as well, as many commenters have pointed out. And we have to buy its reports; they are not made available to the public.

Simply operating a service that stands on its own feet, rather than receiving public subsidy, is a good thing in my view. Standards are produced internationally by committees who are largely unpaid experts in their field, from my experience. They are prepared with integrity, subject to widespread comment before being issued, and regularly updated. If you have evidence that the international standards organisations – ISO, CEN, CENELEC, and national ones like BSI have behaved dishonestly or have been subjected to and yielded to undue pressure from any particular sector then it would be useful to have that presented for discussion.

Meanwhile, on smoke alarms, a meeting is, I understand, due with BSI and I hope we get told of the outcome.

I did mention the committee constitution, but it is a long way out of sight. I thought it worth illustrating again its make up to remind us of the apparent expertise available. I do not know what expertise Which? has that resulted in thinking an international standard is “not good enough” but it will have the opportunity for the experts to meet and thrash this out, I hope, in a constructive way.

I wish Which? was much more open about its work, Malcolm. There is a big difference, however, between BSI, an organisation that (in conjunction with others) is responsible for safety standards, and one, Which?, that is best known for carrying out tests to help us choose washing machines and other household goods.

Information retrieval was an important part of my working life. I find it frustrating not to be able to access documents that are useful to me, having worked in an environment where I could obtain virtually everything I needed.

“I have little confidence in an organisation that is responsible for standards and makes them available online but not to the general public. ”

Interested members of the public are free to purchase copies of BS standards, in the same way as they can pay to receive Which?

The principle is the same – although the prices may not suit all individuals likings.

Perhaps Which? could lobby for more state funding for BSI and for a national free license for UK residents to also get free copies of ISO standards…

I have paid for shareware but I’m not rich enough to pay for copies of standards, particularly since they need to be read in conjunction with other standards.

For the benefit of those unaware of the cost of buying copies of British Standards is high – £244 for the document on smoke alarm devices. An increasing number of scientific papers are freely available to the public because journals have moved from subscription to another funding model. That has not put the existing publishers out of business and new ‘open source’ journals have been set up. I don’t believe that more state funding is needed.

This is old ground that has been well tilled. Standards are international, and all countries charge for them. It helps pay for all the work that goes into preparing them. BSI could not, I believe, unilaterally decide to make them freely available. Would we like the taxpayer to fund access for the few interested people? Many people do not need access to standards, nor have the knowledge to properly use them. There are ways for ordinary people to do so free of charge through some libraries. If local authorities were amenable to funding access for their local residents then this could perhaps be the simplest way to deal with it.

I have suggested before that maybe Which?, assuming it subscribes to the online service, could arrange for nominated interested individuals to have access. Have you pursued this with them?

There are ways for the public to access standards on line, Derek, if they look hard enough.

I agree with the frustration at losing access to useful information.

Which? had entered the standards arena by criticising an international standard. That requires substantiation. It is not just “carrying out tests to help us choose.”

I think the decision could be made for BSI. I doubt that the taxpayer contributes much towards the cost of making scientific articles available, though research council grants include funding for publishing the work they support.

What you are suggesting would not be allowed under the conditions of licensing imposed by BSI. If you visit a library that does provide access to the standards you can print only 10% of an article and may not make a digital copy.

Companies that pay for access to standards pass on costs to their customers, so if I buy a smoke alarm, then I consider that I have already paid for access.

I have looked at various British and ASTM standards and I did not find them complicated – well not compared with molecular biology..

I cannot make copies either. But reading is OK.

Would you like access to all the machinery, computing, photocopiers, for example in a company who made your smoke alarm? You’ve paid for it (or have you?). Seems a curious argument.

Who pays for university research work on which these scientific articles are based? “It is clear that the income universities in the UK receive for teaching, research and innovation activities comes from a wide range of sources. While less than one fifth of income for teaching comes in the form of direct government grants, 66% of income for research comes from government. In total,only around a quarter of the income that universities receive comes directly from government sources. ” If I’ve read this information correctly it seems reasonable to make the results of research paid for from the public purse available.

Have you talked to Which? about seeing whether you could arrange access to standards? I imagine if they have online access it will be made available to nominated people in the organisation. Maybe if you are a Member, Which? could form you, and other interested parties, into a co-opted group helping Which? technically and therefore justifying access.

I suggest we get back to discussing smoke alarms and their effectiveness. We are well off-topic.

The Which? report revolved around the existing standard and that is what I have been commenting on, until the Convo was diverted. Until we hear of the outcome of discussions between Which? and BSI, what should we consider next? It would be useful if Which? could tell us what work they have done to show that, in the 4 fire tests, the envelopes within which domestic smoke alarms should sound can be reduced.

If you would like to help me, please pass on the BS access information to Lauren and ask her to pass it on to me. I’m fairly sure that I can explain how to make copies.

There seems to be a misunderstanding as to Which?’s capability to engage. For over a decade the testing has been contracted out so there is no inherent expertise within Which? on testing.

I am unable to access the Which? link on tested alarms fully as I can only see the wood fire results of the type of fire. I was left wondering which sort of fire is most common – wood I think being the least likely in most households. The Which? expert tests are not fully explained – compare this to the the Australian testing methodology:

“Our expert testers

CHOICE maintains a highly professional NATA-accredited laboratory and the vast majority of our product testing is done in-house. However some tests, including smoke alarms, demand particular expertise and equipment that we don’t have, so in these cases we engage an accredited external lab to do the testing according to our requirements.
How we choose what we test

With so many to choose from, what makes us choose one smoke alarm to test over another? As with most of our product testing, our aim is to test the most popular brands and types on the market and what you are most likely to see in the shops.

We survey manufacturers to find out about their range of products, we check market sales information and we also check for any member requests to test specific models. From this information we put together a final list that goes to our buyers. They then head out to the retailers and purchase each product, just as a normal consumer would. We do this so we can be sure the products we test are the same as any consumer would find them and not ‘tweaked’ in any way.
How we test

We test a mix of photoelectric, ionisation and dual sensor alarms. These include mains-powered and battery-powered models, including several with 10-year lithium batteries. Our buying guide explains the differences between these types.

The alarms are tested in a special smoke sensitivity chamber, equipped with a measurement ionisation chamber (MIC) to measure the concentration of small particles in the air, and optical sensors to measure the concentration of large particles in the air. Each alarm is subjected to a variety of fire and smoke sources, to determine which models:

are best at detecting real fire situations
are not too sensitive to nuisance smoke and fumes (such as when making toast)
are easy to use and have useful features such as a hush button.

Performance tests

Each alarm is subjected to the following “real fire” test scenarios.

Burning (flaming) wood
Smouldering wood
Burning (flaming) cooking oil
Smouldering polyurethane foam

They are also tested for responsiveness to nuisance smoke sources:

Toasting bread in a toaster
Smouldering oil, as in a frying pan
Cooking a hamburger patty

These nuisance smoke sources can set off a smoke alarm, and the result is often referred to as a “false alarm”. But it’s not really a false alarm, as the smoke alarm has genuinely detected particles from a potential fire. (A real false alarm would be if the alarm went off with no smoke in the air at all; this could be due to dust or an insect getting into the alarm, or an electrical fault.)

No smoke alarm can actually tell the difference between nuisance smoke and a real fire; the challenge is to get the alarm’s sensitivity just right.

The above tests are done with the smoke source contained in a smoke box, and the smoke introduced to the separate smoke sensitivity chamber (containing the alarms and the measuring equipment) via a duct. We also included tests using “proxy” smoke sources placed directly in the smoke sensitivity chamber:

Paraffin oil burner
Incense (or “punk”) stick

All the tested models are certified to the Australian standard for smoke alarms, AS 3786, as required by law. Our test is based on a different set of tests and criteria than the Australian standard; the standard sets a minimum performance requirement for each alarm, but doesn’t rank them on comparative performance. Our test is intended to measure how the tested alarms compare to each other.
Ease of use tests

The lab checks:

the clarity and completeness of the supplied instructions
how easy the alarm is to install
how easy it is to install a new battery.

Test criteria explained

The overall score is made up of:

Performance 80%
Ease of use 20%

Performance is based on the comparative speed of response (i.e. how quickly the alarm responds, compared to the others in the test) under similar smoke levels in a range of test scenarios. For the nuisance alarm score, a high score means the alarm is slow to respond to nuisance sources; for all other scores a high score indicates a fast response.

“Real fire” scenarios 70% (made up of smouldering foam 40%, burning wood 20%, smouldering wood 20%, and burning oil 20%)
Nuisance source score 30% (made up of the scores from the toast, smouldering oil and cooking hamburger patty tests, equally weighted)

The smouldering foam score is weighted more heavily than other “real fire” tests because it’s the best source of large smoke particles and an alarm should be good at detecting this common and dangerous fire scenario. A lot of modern furniture (including sofas and mattresses) contains polyurethane foam or similar material and this material can smoulder for a long time, producing a lot of toxic smoke before it finally bursts into flames.

We don’t factor the proxy sources in the score as they give very similar results to the “real fire” tests and are mainly performed as a sense check.

Ease of use is based on the ease of installing the battery and the alarm, and the supplied instructions, weighted equally.”

As I have reluctantly said before, I do not want to prejudice what might be a fragile link to BS Online. I don’t normally need to make copies, but if necessary I have found a way to print and to select extracts.

Have you asked Lauren about accessing through which? I don’t think we’ve ever had a definitive response as to whether, for appropriate Members, they could provide access. It does seem a legitimate aid to Convos. Although in the past Which? have not been forthcoming about the content of standards when it seemed relevant to progressing a Convo.

@ldeitz I assume you do have access to BS Online?

The four standard fire tests are those in the BSEN, and I believe are those used by Which? I presume Which? use appropriate facilities and appropriate staff to test alarms to the BSEN standard. I wondered who understood the topic well enough to make the comments about the “inadequacy” of the international standard and assume Which? employ or consult appropriate experts to reach this conclusion. Resolving this is what I hope Which? and BSI will do when they meet.

If, Patrick, you believe Which? do not have the expertise to “engage” with experts when discussing test results then I would be extremely concerned about the value of some of their comments. However, I would hope that even if they lack in-house expertise, they consult external experts and, hopefully, ask the right questions. They have a responsibility to provide accurate information and comment, both to their Members and to the manufacturers of products they test.

Patrick wrote:

There seems to be a misunderstanding as to Which?’s capability to engage. For over a decade the testing has been contracted out so there is no inherent expertise within Which? on testing.

I don’t believe that Which? claims to do advanced testing or to have staff with the expertise that some of us would like. Many organisations employ independent test labs and these should be able to provide expert comment.

I am unable to access the Which? link on tested alarms fully as I can only see the wood fire results of the type of fire. I was left wondering which sort of fire is most common – wood I think being the least likely in most households.

I’m not sure where you are looking but I’m sure there is plenty of wood in most homes.

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I do indeed and thankfully I never had to sign it.

Just get a VPN, Duncan.

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And you can then use something like ‘Text extractor’ (Mac app store) to get the text.

Thanks Ian. I will look at the possibilities.

BSI supply a list of libraries that provide access to British Standards online. I provided this in past Convos; contacting BSI will give the details to anyone interested.

A brief list is given here but, I believe, there are others. https://www.bsigroup.com/en-GB/about-bsi/uk-national-standards-body/Library-Access-to-Standards/

If you use Windows, a (slightly long winded) way to print is to use “print screen”, copy to a Word document and crop it (picture tools) to fill the page. If you want to select text for copying, save as a .pdf. However I’m sure there are more efficient methods that someone will provide.

In December 2016, BSI provided the following list of places offering access to British Standards:
Kent Libraries and Archives
Maidstone
ME14 2LH
MLA – Bolton Public Libraries
Bolton
BL1 1SA
MLA – Essex Libraries
Chelmsford
CM1 1LH
MLA – Hull Libraries
Hull
HU1 3TF
MLA – Sheffield Libraries &
Sheffield
S1 1XZ
Belfast Education & Library Board
Belfast
BT1 1EA
City University Library
London
EC1V 0HB
Durham University Library
Durham
DH1 3LY
Heriot-Watt University Library
Edinburgh
EH14 4AS
MLA – Cambridge Central Library
Cambridge
CB4 2BB
MLA – Doncaster Library
Doncaster
DN1 3JE
MLA – Lancashire County Library
Preston, Lancashire
PR1 2PP
MLA – Manchester Public Library
Manchester
M2 5PD
MLA – Norfolk CC Library Service
Norwich
NR1 2UA
MLA – Staffordshire CC Library &
Stafford
ST16 3HJ
National Library of Wales
Aberystwyth
SY23 3BU
Newcastle City Library
Newcastle Upon Tyne
NE1 8AX
Reading University Library
Reading
RG6 6AE
Strathclyde University Library
Glasgow
G4 0NS
The British Library
London
NW1 2DB
The Open University Library
Milton Keynes
MK7 6AA
University of Northumbria-Library
Newcastle Upon Tyne
NE1 8ST
The Oldham College Library
Oldham
OL9 6AA
The University of Manchester Library
Manchester
M13 9PP
Coventry Libraries and Information
Coventry
CV1 1FY
Liverpool City Libraries
Liverpool
L3 8EW
North East Scotland College Library+
Aberdeen
AB21 9YA
ROnline-Kent Libraries, Registration and Archive
Maidstone
ME14 1LQ
University of Sussex Library
Brighton
BN1 9QL

I thanked them and pointed out that this list did not correspond to the list on their website but no action was taken. There is no reference to the fact that BS Online is available to members of the Glasgow Libraries and documents can be downloaded, according to the Glasgow website.

At present, access to British Standards is available to all via this link: http://www.manchester.gov.uk/directory_record/162241/british_standards_online/category/1216/business_and_careers

Printing and saving web pages are disabled but screen captures of pages can be saved as pdfs (tedious) and assembled into a single document using appropriate software (easy).

Standards that are relevant to our safety should be made publicly available.

Apparently, through online access at least, they are.

Not officially, as you know well. I found this page recently with a search for free access. I hope that someone at Manchester Libraries agrees with me that they should be freely available.

For those who want to look at British Standards, they are basically European Standards, beginning BS EN. The number is the standard number. It may be in a number of parts. The ones relevant to the current topic are covered by BS EN 60335 series.

Part 1 – BS EN 60335-1 – is entitled “Household and similar electrical appliances. Safety. General requirements” and cover matters generally applicable to all such appliances.

Part 2 contains lots of sub-parts that then each cover the specific requirements applicable to particular appliances, which will add to and modify the requirements of Part 1 as appropriate. So, for example, Tumble dryers are dealt with in BS EN 60335-2-11.

Each standard carries a date – :2010 in the above case, when it was last fully reissued, plus any amendments incorporated since then – in this case +A1:2015. It also shows whether work is in hand or whether it has been revised (older versions).

To find the required part needs a little input precision. One way is to simply put BS EN 60335 in the advanced search box, which in this case produces a list of all the relevant documents (including drafts, superceded ones) – 445 in this case – and then put a key word in the “search within results” box to find the specific standard. Alternatively, Google a required standard and just put the number in the search box.

I’d be interested to know how many commenters will examine standards routinely when an appropriate topic arises.