See what you're spewing

and potentially help people reduce their emissions by adjusting their driving style.

Or maybe if they just switched off the engine whilst waiting to pick up their kids from school?

I don't need a laser to see the cloud of carcinogenic black carbon dust that blows from every modern turbo diesel when accelerating away infront of my car's ventilation fan. Why do the regulators ignore this little facet of diesel cars? And, why is nobody making a fuss about it as it looks lethal and it is getting worse. Every time I have to drive through one of those little clouds I hold my breath, but I shouldn't have to. Why are particle filters not compulsory? Because they get blocked with carcinogenic black carbon dust, and disposing of them would present health issues! Better to spew it into peoples air intakes.

Whoa there! Mewebe, I don't think you work in the emissions field. I'll take your points in order and try to give you some idea of what's going on in this field/industry

As a general point on diesel engine exhausts: if you can see, it won't harm you as your personal filtration device (your nose) will remove it before it gets to your lungs - no I'm not saying we shouldn't filter!

"carcinogenic black carbon dust"
It's rather more complicated than that. Whilst a large proportion of the smoke is elemental carbon, it is usually coated in a number of gaseous precipitates that render it sticky and very undust-like. There are also metal particles and ash particles in this "cloud".

"Why do the regulators ignore this little facet of diesel cars?"
They don't, and haven't for quite some time now. The first EU legislation was issued in 1972 (72/306/EEC); this has now been superseded by 2005/55/EC. These pieces of legislation and their amendments put in place the various levels of emission control that have been agreed over the years: these are known as Euro Levels. Vehicles currently being produced have to meet the Euro 4 Level; Euro 5 is introduced in 2008, Euro 6 in 2012 (possibly, the exact implementation date has not yet been decided; there are considerations of how to incorporate new measuring techniques and new understandings in what happens in a gas stream at 200 - 500°C to be resolved). Manufacturers are already designing to meet these limits. The time scales are set to give the industry a reasonable chance of meeting the limits, whilst "encouraging" innovation.

In order to be Type Approved (in accordance with 70/156/EEC), an engine must be tested to the test procedures set out in 2005/55/EC. This includes bench testing at specialist test houses (known as Notified Bodies, who are inspected to far higher standards than the ISO 9001 or even TS16949 quality standards) to specific test cycles. These test cycles include cold start elements, hard acceleration, urban, suburban and motorway driving sections. The limits on a number of gaseous and the raw weight of particulate matter are set. If the engine does not meet these limits, it can not be sold in the EU. End of Story. No get Type Approval, No can sell.

The legislators have caused emissions levels to be drastically reduced over the last 30 years; the graph below will show you how much. We are now at the limit of measurement capability, hence the reluctance to reduce limits further until new techniques have been fully calibrated (there is a "Gold Standard" project being carried out between several equipment manufacturers and test houses to do this and to ensure that the same results are given at all locations).

And the engine manufacturers have done this whilst improving fuel consumption and performance_ that's one, no several hell(s) of an achievement!!!

"Why are particle filters not compulsory?"
Because to prescribe a method of solution contravenes the EU's competition laws. What the EU does is to set limits for the emissions allowed to exit the exhaust, and these limits are back calculated from the Air Pollution targets. For all we moan about the EU (and I do), there is quite a bit of "joined-up government" going on in Brussels and Strasbourg.

For example, in order to reach Euro 4 levels, a manufacturer can take his Euro 3 engine, add a particulate filter (or better still a CRT^TM; but I'd better not say that as it's advertising!!) tune it a little and reach the PM target. Alternatively, and many manufacturers (Heavy Duty) did this, they redesign their engine to use EGR (Exhaust Gas Recirculation) to reduce both PM and NO_x emissions. Outcome: both types of vehicles meet the targets: one has a filter which needs periodic cleaning of one sort or another and one doesn't.

"Because they get blocked with carcinogenic black carbon dust disposing of them would present health issues"
Actually the carbon is easy to get rid of - if the exhaust temperature is high enough (400-500°C in raw state, 250-300°C in a catalysed state), it turns into CO₂. Now, I know CO₂ has its own issues, but if you're going to burn fossil fuels, you're going to get CO₂. And it it's not, you can remove the filter from the vehicle, heat in an oven to 500°C and remove it that way.

The problems actually come from the ash residues from the oil that passes the piston rings, and from unburnt HC (hydrocarbons) and other "sticky" deposits. Filter unit manufacturers have several mechanisms for removing these (filter off vehicle). Filter substrate manufacturers are doing a lot of work to design filters that will last for the life of the vehicle. I think LD (Light duty - cars/engines below 3 -4 litres) probably have reached this. There is work in the HD market to get to this point, meanwhile the company for whom I work offers a filter exchange service, as do a number of other similar companies.

"it looks lethal and it is getting worse"
What B$%%$^*s!!!!

Since when has how something looks been a measure? This is a very technology intensive field. Yes there are lethal compounds that leave exhaust pipes - and believe me elemental carbon is one of the nicer things [Gang (you know who you are!) forgive me the implication in this sentence that carbon might be a compound...the English would be too torturous otherwise] that comes out of a vehicle.

It is most definitely getting better - all London buses have filters fitted (90% of them ours ) and the air quality in London is improved. It's not perfect and more work needs to be and is being done about that. Air Quality isn't getting better as quickly as some politicians and legislators want - and so LEZ (Low Emission Zones) are being introduced around Europe - London will have one, the Dutch scheme is up and running, Germany will follow...there are about 20 in various stages of planning.

I've only talked about the EU Legislation as that's the stuff with which I'm most familiar. The US has a number of regulations, both National and State. the most advanced is the CARB (California Air R(something) Board).

Go google a few terms, follow my links and find out what's actually going on before you sound off. And remember - the car in front may a) too old to have a filter fitted or b) have removed it to increase performance.

if you can see, it won't harm you as your personal filtration device (your nose) will remove it before it gets to your lungs

I worked for many years designing measuring instruments for respiratory measurement particularly in the field of asthma.

I don't want to be dogmatic (falls off chair laughing at the 'D' word) but I think this statement is somewhat short of accurate.

Did you read the rest of the post?

I thought I'd make my opening comment as vague as mewebe's whole post

I wasn't saying that there's nothing to worry about, rather that if you stop worrying when you can't see anything, you're a fool. And I get very irritated by those people who equate visible black smoke with lung problems. We've improved (reduced) the amount of visible vehicle emissions, but asthma rates are still rising...because of those pesky invisible nanoparticles!!

And I stand by the statement that if you can see the particles they're too darned big to get down into your lungs. You can't see the nucleated particles of various acids that are formed; these do get into your lungs and cause a great deal of damage/problems. Generally, these are what are left when all the elemental carbon has been filtered out (slight over simplification, but I don't have the graph in electronic form). These nanoparticles have been shown to pass through into the blood and even to permeate through the blood-brain barrier.

As you will know (that's supposed to be a friendly comment indicating that I respect your experience and knowledge - but you knew that too), there is a whole spectrum of particle sizes, which are deposited at a depth in the breathing apparatus inversely proportional to their diameter; I was only refering to the large ones.

What particles types and sizes were you measuring?

Cheers (you should know by know I don't actually read anything (longer than about 5 lines) !

I wasn't actually measuring particle sizes but I dealt with some of the country's leading Asthma experts (Dr Martin Wright [now deceased], Ian Gregg, Martin Miller...oooh what a name dropper...).

I was keen to boldimicate the word 'think' in my post,(I don't want to set myself up as an expert to be shot at ) many things can trigger asthma and I'm pretty sure I've read that deisel particulates are a culprit.

Self evidently pretty large particles can get into the brochial tract, the upper reaches of which become constricted in asthma.

I'm just rather wary of any excuse to not remove particulates.

In terms of the Euro stuff I applaud your knowledge and your patience at explaining all...the Eurocrats do rather get a bashing!

Cheers ER..I'm off to play golf now so....cheerio!

"I'm just rather wary of any excuse to not remove particulates"
Quite understandably. Line 5 (so you should have got that far...) of my first post does say "I'm not saying we shouldn't filter"

I'm sure diesel particluates are a factor in (some?) asthma cases - just not the big black so-and-sos (over 1mm diameter) that you see in the classic Big Black Cloud. It's my understanding that the ones to worry about are the PM10s (anything smaller than 10 microns), which petrol engines produce more of in their lifetimes. Focus is now moving to PM2.5s and below.

First identify, then measure, then remove...that's the general way forward. The exhaust issues is slightly clouded (did you see what I did there?) by the fact that the so-called nanoparticles aren't particles whilst in the gas stream - they're gaseous. They nucleate or precipitate out when the hot gases are diluted and cooled by atmosphere. So they're a bit of a challenge to remove.

A lot of work is being done (mostly in US and in conjunction with health researchers) on their dwell times, half lifes, migration patterns. After all, if they disappear by one mechanism or another with 5 minutes, there's probably no point is spending huge sums removing them - it might be cheaper & more efficient to remove their secondary products; but if the cloud always heads to the nearby school, you want to do something.

Just to give people an feel for the costs:

A new truck can cost approximately £250,000,
its engine about £20 -40,000,
its exhaust aftertreatment about £10,000.

You don't want to be adding unnecessary technology at those prices.

Hope the golf was good (you need to find the motivational picture in the rainfall thread!). I'm off home...yippee!!!

PS. Just before I left the company we were working on dry powder inhalers and nebulisers. These would both be useful search areas if wish to research particles size/lung penetration further....

To the golf course Cat Man! Dah dah dah dah dah dah dah dah CAT MAN!

Thanks for all the info on regulations, and on the real nasty chemicals, but there are certain facts being avoided. The first is that some people breathe through their mouth, and especially people with asthma. Second, carbon dust is carcinogenic, and third, cars are allowed to be designed to emit clouds of carbon dust and still pass the tests. The result is turbo diesel vans and cars that out sprint petrol engined sports cars. They should have their "fuel computers" programmed to avoid the black clouds of dust region, at the expense of some of the acceleration performance. The marketing men may not be happy, but it would stop the white van men having the advantage. The facts are that new turbo diesels still blow out clouds of black carbon dust as manufacturers have found their way around the regulations. They can tune their fuel computers to give ever higher acceleration instead of reduced emissions and get away with it. Cutting the black dust throttle opening would also cut fuel consumption, noise, and the other nasty emissions. Why not legislate against it?

As well as the legislation on emissions, which as I said is cascaded down from the European Air Quality targets (which all EU countries are legally bound to meet, on pain of fines - although as none are likely to meet it, fining is unlikely to happen!), there are also separate regulations on:

a) fuel consumption - not sure how this one is implemented, as I don't work for an engine manufacturer. There are requirements for manufacturers to meet "fleet avaerages", so they can have a range of vehicles from th eultra efficient to the gas guzzler (i.e. legislation doesn't restrict trade or the market). Also, all of the retrofit legislation require that the emissions retrofit kit (i.e. the exhaust aftertreatment that is likely to result in higher exhaust back pressure) doesn't result in a loss of more than 4% on fuel consumption.

b) noise - 70/157/EEC as amended by 1999/101/EC (I think that's the latest, haven't had cause to check recently!). This limits the noise produced by vehicles. Like all legislation (not just vehicle related!), manufacturers "design to meet it". It has taken 5 or 6 years so far of much research and testing for the EU Working Party to develop and agree on a new test method and suitable limits. The new test is designed to more closely represent current driving practice and to put more weight on the current top noise sources in vehicles. Reducing noise on vehicles is like swamp draining - as you get rid on the really big contributors (engine, intake, exhaust and gearbox), so the other tyres, wind/aerodynamic, sqeak & rattle, become more important. Reducing noise also means making combustion more efficient (lower fuel consumption) and looking at acceleration rates.

c) The other "nasties" are starting to be legislated against. One of the big problems is measurement. The legislators can't set limits unless accurate and repeatable measurements are possible. There are several Notified Bodies in each EU State; everyone has to be confident that each of these gives the same results for each of the tests, otherwise manufacturers don't have a level playing field.

One of the points you may not have picked up on is that none of this legilsation is retrospective. If you buy a car that was first sold in 1990, it must meet the the legislation in place in 1990. Buy a car today and it must meet today's standards. There are some moves to force retrofitting of aftertreatment - the LEZs (Low Emision Zones) are one such measure. Basically, these say that if you don't meet a certain level of tailpipe emissions, then you have to pay to enter the zone. Usually, the fine means that after about 10 - 20 visits, your aftertreatment has paid for itself.

Please understand that things are being done. However, this is (at least in Eurpoe) a cross border, international effort and the wheels or such organisations grind slow - at least the slow grind makes kneejerk unthoughotout reaction unlikely. The Working Parties are composed of Engineering experts in the appropriate fields and whilst there's a fair dose of nationanl politics involved, the engineering isn't lost.

Just imposing qualitative limits on "black smoke" would be perceived by the public as a "bad law" - having said that I know the UK has a similar law, designed to stop someone driving a car with blown rings...the prevents anyone from "obscuring the view of the carriageway" - so a small puff won't get ou stopped, but belching smoke all the time would (or should).

What's your engineering background? With your passion for this subject, perhaps you should consider moving in to the field?