Getting the Lead Out

What I would like to know is, why do you have to use lead, and in what coulour paints????????????????????????????/

Spencer.

To achieve high gloss in all colours.

Codswalop - you get the most stable colours with good opacity - nothing at all to do with the gloss.

These days lead pigments are virtually non-existent especially in domestic paints in the civilsed world - maybe still some in the banana republics.

I think that this fixation with paint is a problem as the real culprit sneaks past us.

Lead in lethal quantities has not been used in paints of any calibre for years.

Really.........?

How would you explain the recent recall of toys that were made in China which, incidentally, included some of the largest toy manufacturers distributing them?

go back to my earlier reply

"These days lead pigments are virtually non-existent especially in domestic paints in the civilised world - maybe still some in the banana republics."

In my book China is one of the biggest banana republics of the lot - growing too fast to keep up with the controls. in any case I have seen some of these toys and those I saw had little highlights using chrome pigments - which have a low soluble lead content. Each child would have to have eaten quite a large number of these toys!

Lead is a common element and has been made widespread not because of paint but I believe gasoline. It has been spread widely around and lead on paint is probably a greater problem than lead in paint. The lead content of bread can also be high - the corn gets it from the air! Authorities need to dedicate more time and effort to establish the real cause. The reduced lead in gasoline resulting from the need to keep down smog by the use of platinum exhausts which are killed by the lead will probably contribute greatly but we still have a backlog of many years of lead spewing out to get out of the system. Compensation motivated court cases just add fuel to the fire. The main culprits in the lead paint story are the old lead primers, red and white, now long gone.

Interesting. I based my info on media sources which claimed the actual 'paint' on the toy contained lead in order to bring out the gloss. A boat I own used lead white as a primer...also a few canvasses hanging on the walls.

Further to the topic of toxics I've always wondered whether the pigments used in indoor paints may one day become airborne particulates. I've noticed that acrylic indoor house paints degrade into a fine surface dust given a few years.

Generally pigments are not a great problem the one used for primers Lead and zinc chromate for example are dodgy because they have reactive properties. Other pigments are chosen because of their stability and lack of reactivity so in general can be considered as inert. The chrome lead pigments used for colour are also stable but do have some solubility in HCl. When checked out there is possibly more problem due to their being chromates rather than having lead and this is a greater problem for the people making them than those using them in paints where they are encapsulated.

Unless they are rubbish (not unlikely if made by back-yard manufacturers) interior paints just collect dirt rather than lose it. A regular re-coating to freshen them up will reduce deterioration. Exterior paints are another story - the effect of UV and the environment is the general cause of deterioration but a regular re-coating will minimise any problems. You should always be able to re-coat paints and should never remove an intact one. Poor exterior paints usually degrade by "chalking" and any sign of a removable deposit (usually white) is an indication of a problem.

Paints which crack and peel off which is almost always due to bad preparation and these can prove expensive as they may need to be removed.

I worked with a company that was evaluating the former site of an old Sheffield pigment factory.

Today the 18 acres of land that the factory was built on is completely fenced off and all subterranean water channels are pumped constantly in order to prevent the toxic plumes from spreading further into the water table.

That is probably due to the process chemicals - that is why the chromates are a problem - probably more than the lead. The pigments themselves have to be as inert as possible otherwise they cause problems often with the binder as well as being unstable. Currently there is a big exercise REACH going down in EC to reclassify all chemicals. Keeps me in business!

There are many old plants in the states causing big hassles due to the errors of the past.

Remember that old north country motto - "where there is muck there is money" when you have to get the muck out the money tends to disappear.

Recall analysis of soils at this site sent alarm bells ringing. Chromates, heavy metals, arsenics and a host of other nasties....some of which were leaching into the water table. Others on the surface.

City council wanted to develop the land. Cleanup costs astronomical so filtration units were set up instead. Surface soils have to be regularily coated with bonding agents to prevent being blown away by winds.

Scapolie,

Lead was (and still is) added to paints for several purposes:

• As a pigment - lead chromate makes the paint yellow (this is the industrial safety yellow), and also in the form of lead carbonate, which is a high quality white paint pigment. These pigments are quite opaque, so the resulting colors are vivid, and required less pigment than from other, less opaque sources. While not used in consumer paints manufactured in the USA, these pigments are still used in industrial coatings;

• White lead (lead carbonate) is highly insoluble in water, thereby making paint containing appreciable concentrations of this pigment washable, and weather resistant;

• Lead was added to paint as a drying agent, and to improve durability. Lead improved the durability by maintaining elasticity/flexibility of the film coating. For these applications, the opacity of the pigment was not critical, and lead was even added to shellacs & varnishes.

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Just my $0.02...

You are way out!

Lead chromate and other pigments are highly resistant to weather and are very cost effective. The thing that can matter is the soluble content while they can have fairly high levels of lead the nasty bits are those which will dissolve in 0.1N Hydrochloric Acid (equivalent to stomach acid and therefore taken into the system)

White lead an excellent primer for wood but (except for dedicated artists) has been discontinued in favour of titanium for many years as a white pigment. Titanium is cheaper, whiter, has better opacity, does not react with the binder and is more colour stable as well as less toxic.

Lead as a drier was used in insignificant quantities as a drier in oil paints but has fallen by the wayside due to the general paranoia - zirconium is one of the substitutes.

I use EC standards for toxic classifications and as with all such chemicals their use is not prohibited providing you tell the user that it is present and how much.

Lead chromates still have their uses - eg Road Line Paints.

hazman,

Would you mind translating "You are way out!"...

Is that a term of agreement, disagreement, or something else?

I've been accused of being "way out of line" before, and even of being "far out", (but not since the 70s!)

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You state :

"I think that this fixation with paint is a problem as the real culprit sneaks past us."

I personally have sampled paint applied to the exteriors of (old) non-industrial buildings that upon analysis was found to contain more than 30% lead by weight.

What do you believe is the "real culprit" ?

Lead in gasoline?

Well, lead in gasoline has been banned for decades in the USA - How about in South Africa?

"The lead content of bread can also be high - the corn gets it from the air!"

Here in the USA, we don't make much bread from corn - we are under the delusion that it's better to make ethanol out of it (!?!)

BTW, I find the "conversation" that you and duckinthepond are having more than 6

months after the OP, and nearly 5 months after the last comment kind of amusing...

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As always,

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Just my $0.02...

We seem to be in a semantics issue "way out" or "far out" same to me.

Corn to me is any grain - where I come what you call corn is called Maize - more specific!

(No wonder me and Bill Gates keep crossing swords with his dictionary)

In the USA there are many more wooden houses and, probably due to the efficiency of white lead, they last one hell of a long time - as long as nobody eats them they will do them no harm. Lead as a wood primer probably faded from the scene some 25-30 years ago - did here and in UK.

Lead is being dropped (recent in South Africa) - main reason for dropping it in USA was I understand to make the platinum exhausts work to reduce smog.

As lead is such a stable product the lead pushed into the atmosphere from exhausts over the last 100 years must be quite considerable and it must be somewhere (law of conservation of matter). Lead is accumulative in the body & in other places.

As the lead in the old homestead is harmless (so long as you leave it there) and the paint industry stopped its contribution some years ago, and lead appears to be cropping up all over it appears that someone stopped straight line thinking and went lateral. The obvious explanation is not always the correct one!

The most dangerous form of lead is in the shape of a bullet and this is the most common form of lead-related deaths - at least in Africa.

I would be more interested in learning about heavy metal leaching from pipe fittings. I understand California has started legislation targeted at imported and poorly made metal products that are ending up in residual applications.

Products are visually similar to "good products" but contain (and leach) mercury, lead, and some other nasties.

Is this worthy of a new post?

Damn right it is!

Hi Paddler,

Thats why I asked!

Here in Europe we are not allowed to have lead in paint, but we still have high gloss paint!!!!!!!!!!!!!!

Spencer.