On Monday, September 27, 1999 at 8:00:00 AM UTC+1, Anthony Hay wrote:
While decorating I recently removed some wallpaper and revealed some
dark green mat paint. I don't think it is an oil based paint. It's on
lime plaster. A friend told me arsenic was used to colour paint in years
gone by. The house is late C18.

Does anyone know how I could test for arsenic?

Does anyone know how to get rid of arsenic paint?

(Wasn't it arsenic in the wallpaper that killed Napoleon?)

Worried of Wiltshire

Hello Anthony

Green paint from the 18th and 19th circa is likley to contain arsenical pigments such as copper arsenate and/or lead arsenate.

They are both highly toxic.

Because of this, I strongly advise you NOT to attempt to remove the paint as this would greatly increase your exposure risk not to mention how will you dispose of - legally - the old paint.

My advice is to over paint with several coats of good quality paint. You can also paper it over before painting. If the paint is present in damp areas subject to mould growth use an anti-mould paint undercoat. Its mouild that turns arsenical paints into potential killers. If you or your family are worried about arsenic exposure, your GP can arrange a blood or urine test for heavy metals.

You have done the right thing by sending a sample to an approved laboratory..

Try not to worry too much, the best course of action is not to disturb the old paint and cover it with fresh paint and/or paper the offending paint before painting.

I am a registered chemist specialising in toxicology so feel free to ask anytime you are concerned.

Best wishes

Simon

wrote:

On Monday, September 27, 1999 at 8:00:00 AM UTC+1, Anthony Hay wrote:

I am a registered chemist specialising in toxicology

But not very observant about dates.

--
Scott

Where are we going and why am I in this handbasket?

On 15/03/2016 12:06, Scott M wrote:
wrote:

On Monday, September 27, 1999 at 8:00:00 AM UTC+1, Anthony Hay wrote:

I am a registered chemist specialising in toxicology

But not very observant about dates.



Does Google Groups just dredge up these old posts without any warnings?

On Tuesday, 15 March 2016 13:08:43 UTC+1, GB wrote:
On 15/03/2016 12:06, Scott M wrote:
wrote:

On Monday, September 27, 1999 at 8:00:00 AM UTC+1, Anthony Hay wrote:

I am a registered chemist specialising in toxicology

But not very observant about dates.



Does Google Groups just dredge up these old posts without any warnings?

No (and I post through GG).

On Tue, 15 Mar 2016 12:08:39 +0000, GB
wrote:

On 15/03/2016 12:06, Scott M wrote:
wrote:

On Monday, September 27, 1999 at 8:00:00 AM UTC+1, Anthony Hay wrote:

I am a registered chemist specialising in toxicology

But not very observant about dates.



Does Google Groups just dredge up these old posts without any warnings?

No. deja.com was always intended to be a Usenet archive, not a
substitute for a news server and news reader client.

When Google acquired it in 2001 they set about merging it into their
own "Google Groups" and tried blur the line as to what is Usenet and
what wasn't. I doubt if Scott has even heard of Usenet

--

Graham.

%Profound_observation%

On Tue, 15 Mar 2016 14:32:40 +0000, Graham.
wrote:

On Tue, 15 Mar 2016 12:08:39 +0000, GB
wrote:

On 15/03/2016 12:06, Scott M wrote:
wrote:

On Monday, September 27, 1999 at 8:00:00 AM UTC+1, Anthony Hay wrote:

I am a registered chemist specialising in toxicology

But not very observant about dates.



Does Google Groups just dredge up these old posts without any warnings?

No. deja.com was always intended to be a Usenet archive, not a
substitute for a news server and news reader client.

When Google acquired it in 2001 they set about merging it into their
own "Google Groups" and tried blur the line as to what is Usenet and
what wasn't. I doubt if Scott has even heard of Usenet

Now their's a thing, now I've bothered to check, Scott isn't posting
via GG, he's using aioe.org.

So how's that happened?

--

Graham.

%Profound_observation%

Apologies Scott, it's Simon who trawled up the old post not you!

Also the actual OP Anthony Hay had a sample analized and it came back
as 24 parts arsenic per million parts paint.

https://groups.google.com/d/msg/uk.d...E/LcXOKHEu1UIJ





--

Graham.

%Profound_observation%

On Tuesday, 15 March 2016 15:52:48 UTC+1, Graham. wrote:
Apologies Scott, it's Simon who trawled up the old post not you!

Also the actual OP Anthony Hay had a sample analized and it came back
as 24 parts arsenic per million parts paint.

https://groups.google.com/d/msg/uk.d...E/LcXOKHEu1UIJ

Which to put into context is less than the level at which people start
being worried about arsenic in soil: 32 mg/kg

https://www.gov.uk/government/upload...09bpvy-e-e.pdf

I think I'd still prefer to wet strip it though.

GB wrote
Scott M wrote
wrote
Anthony Hay wrote

I am a registered chemist specialising in toxicology

But not very observant about dates.

Does Google Groups just dredge up these old posts without any warnings?

It only shows the date, which is clearly easy to miss.

On 3/15/2016 12:00 PM, wrote:
On Monday, September 27, 1999 at 8:00:00 AM UTC+1, Anthony Hay wrote:
While decorating I recently removed some wallpaper and revealed some
dark green mat paint. I don't think it is an oil based paint. It's on
lime plaster. A friend told me arsenic was used to colour paint in years
gone by. The house is late C18.

Does anyone know how I could test for arsenic?

Does anyone know how to get rid of arsenic paint?

(Wasn't it arsenic in the wallpaper that killed Napoleon?)

Worried of Wiltshire

Hello Anthony

Green paint from the 18th and 19th circa is likley to contain arsenical pigments such as copper arsenate and/or lead arsenate.

They are both highly toxic.

Because of this, I strongly advise you NOT to attempt to remove the paint as this would greatly increase your exposure risk not to mention how will you dispose of - legally - the old paint.

My advice is to over paint with several coats of good quality paint. You can also paper it over before painting. If the paint is present in damp areas subject to mould growth use an anti-mould paint undercoat. Its mouild that turns arsenical paints into potential killers. If you or your family are worried about arsenic exposure, your GP can arrange a blood or urine test for heavy metals.

You have done the right thing by sending a sample to an approved laboratory.

Try not to worry too much, the best course of action is not to disturb the old paint and cover it with fresh paint and/or paper the offending paint before painting.

I am a registered chemist specialising in toxicology so feel free to ask anytime you are concerned.

Best wishes

Simon


Recognising that this is a very old post, I have also just uncovered
some old green matt paint on a wall, also 18th century although I
suspect that this might be Victorian. I wondered about arsenic too,
since it's not quite the classic colour of verdigris or typical
corrosion of copper. I have a sample waiting to sneak into an SEM with
EDAX next time I have an opportunity.

But I also did some research on the net, and found that it's just the
shade of Malachite, another green pigment with long ancestry. This is
basic copper carbonate, so still a bit toxic but *not* as bad as arsenic.

Some of it came off easily dry with a stripping knife, but some is very
adherent. I deliberately didn't sand it, I tried to avoid inhaling dust
and vaccumed fairly carefully before sealing with PVA, and I am going to
put heavy duty lining paper over it.

Graham. wrote:
Apologies Scott, it's Simon who trawled up the old post not you!

Lucky there; you were about to get both barrels ;-) I started on Usenet
over 20 years ago (god I feel old!)

--
Scott

Where are we going and why am I in this handbasket?

On 15/03/2016 12:08, GB wrote:
On 15/03/2016 12:06, Scott M wrote:
wrote:

On Monday, September 27, 1999 at 8:00:00 AM UTC+1, Anthony Hay wrote:

I am a registered chemist specialising in toxicology

But not very observant about dates.

Does Google Groups just dredge up these old posts without any warnings?

No. But spammers flogging their various services do - using bots that
latch onto particular keywords.

--
Regards,
Martin Brown