Thought this might be of interest:

http://www.cleanpowercanada.bravehost.com/report1.html


mark

On 7 July, 14:04, "mark" wrote:
Thought this might be of interest:

http://www.cleanpowercanada.bravehost.com/report1.html

mark

One to add to the mobile phone nutters.

We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember "mark"
saying something like:

Thought this might be of interest:

http://www.cleanpowercanada.bravehost.com/report1.html

Yeah, get your ghostmeter out
http://www.trifieldmeter.com/

harry wrote:
On 7 July, 14:04, "mark" wrote:
Thought this might be of interest:

http://www.cleanpowercanada.bravehost.com/report1.html

mark

One to add to the mobile phone nutters.

Except this is a genuine problem, although mostly for people who are
sensitive to sunlight. They put out UVA and I got a rash on the back of
my hand from a low energy desk lamp when taking medication that made me
sensitive to sunlight. Even for people without that susceptibility,
working within 20cm of a single envelope low energy lamp brings the UVA
level above the recommended exposure levels in the workplace. Lamps with
an outer glass envelope do not suffer the same problem, but my desk lamp
is now LED and I'm on different medication.

Colin Bignell

"Nightjar "cpb"@" "insertmysurnamehere wrote in message
...
harry wrote:
On 7 July, 14:04, "mark" wrote:
Thought this might be of interest:

http://www.cleanpowercanada.bravehost.com/report1.html

mark

One to add to the mobile phone nutters.

Except this is a genuine problem, although mostly for people who are
sensitive to sunlight. They put out UVA

But the shade on the lamp of the lupus sufferer should absorb all the UVA so
if that was the same lamp it wasn't the cause.

On Jul 8, 9:43*am, "dennis@home"
wrote:
"Nightjar "cpb"@" "insertmysurnamehere wrote in message

...

harry wrote:
On 7 July, 14:04, "mark" wrote:
Thought this might be of interest:

http://www.cleanpowercanada.bravehost.com/report1.html

mark

One to add to the mobile phone nutters.

Except this is a genuine problem, although mostly for people who are
sensitive to sunlight. They put out UVA

But the shade on the lamp of the lupus sufferer should absorb all the UVA so
if that was the same lamp it wasn't the cause.

It also raises the question as to whether some standard sized
fluorescent tubes produce the same effect. Public buildings have had
them for at least the last 50 years.

andyv wrote:
On Jul 8, 9:43 am, "dennis@home"
wrote:
"Nightjar "cpb"@" "insertmysurnamehere wrote in message

...

harry wrote:
On 7 July, 14:04, "mark" wrote:
Thought this might be of interest:
http://www.cleanpowercanada.bravehost.com/report1.html
mark
One to add to the mobile phone nutters.
Except this is a genuine problem, although mostly for people who are
sensitive to sunlight. They put out UVA
But the shade on the lamp of the lupus sufferer should absorb all the UVA so
if that was the same lamp it wasn't the cause.

It also raises the question as to whether some standard sized
fluorescent tubes produce the same effect. Public buildings have had
them for at least the last 50 years.

Most people don't get as close to them as they do to desk or table
lamps. However, where there may be a risk, you can get UV-absorbing
sleeves to fit over them.

Colin Bignell

Tim Streater wrote:
In article ,
"Nightjar \"cpb\"@" "insertmysurnamehere wrote:

andyv wrote:
On Jul 8, 9:43 am, "dennis@home"
wrote:
"Nightjar "cpb"@" "insertmysurnamehere wrote in message

...

harry wrote:
On 7 July, 14:04, "mark" wrote:
Thought this might be of interest:
http://www.cleanpowercanada.bravehost.com/report1.html
mark
One to add to the mobile phone nutters.
Except this is a genuine problem, although mostly for people who are
sensitive to sunlight. They put out UVA
But the shade on the lamp of the lupus sufferer should absorb all
the UVA so
if that was the same lamp it wasn't the cause.
It also raises the question as to whether some standard sized
fluorescent tubes produce the same effect. Public buildings have had
them for at least the last 50 years.

Most people don't get as close to them as they do to desk or table
lamps. However, where there may be a risk, you can get UV-absorbing
sleeves to fit over them.

Yes, I figured that too, but in a large office there are plenty of such
overhead tubes. Or is it that the baffles underneath them, which reflect
a lot of the light, actually absorb the UV so the exposure is reduced?


It is that the radiation intensity is inversely proprtional to the
square of the distance from the source, which means it drops off very
quickly. The intensity at 40cm is 1/4 of that at 20cm. At 80cm, it is
1/16 of that at 20cm and, in most commercial environments, people are
likely to be further from the lamps than that.

Colin Bignell

mark wrote:
Thought this might be of interest:

Not really, the silly bitch was sat with her face pressed against a table
lamp reading a book, what did she think was going to happen?

--
Phil L
RSRL Tipster Of The Year 2008

Tim Streater wrote:
In article ,
"Nightjar \"cpb\"@" "insertmysurnamehere wrote:

Tim Streater wrote:
In article ,
"Nightjar \"cpb\"@" "insertmysurnamehere wrote:
andyv wrote:
On Jul 8, 9:43 am, "dennis@home"
wrote:
"Nightjar "cpb"@" "insertmysurnamehere wrote in message

...

harry wrote:
On 7 July, 14:04, "mark" wrote:
Thought this might be of interest:
http://www.cleanpowercanada.bravehost.com/report1.html
mark
One to add to the mobile phone nutters.
Except this is a genuine problem, although mostly for people
who are
sensitive to sunlight. They put out UVA
But the shade on the lamp of the lupus sufferer should absorb
all the UVA so
if that was the same lamp it wasn't the cause.
It also raises the question as to whether some standard sized
fluorescent tubes produce the same effect. Public buildings have had
them for at least the last 50 years.

Most people don't get as close to them as they do to desk or table
lamps. However, where there may be a risk, you can get UV-absorbing
sleeves to fit over them.
Yes, I figured that too, but in a large office there are plenty of
such overhead tubes. Or is it that the baffles underneath them,
which reflect a lot of the light, actually absorb the UV so the
exposure is reduced?

It is that the radiation intensity is inversely proprtional to the
square of the distance from the source, which means it drops off very
quickly. The intensity at 40cm is 1/4 of that at 20cm. At 80cm, it is
1/16 of that at 20cm and, in most commercial environments, people are
likely to be further from the lamps than that.

For a single source, yes, but in an office there will be several lights.
Now, due to the reflecting baffles, only the one(s) right above will
shine on a person without their light arriving at the person directly,
hence my Q about whether the baffles absorb UV.


That will depend upon the baffle material and design. The ones I had in
my clean room, with glass panels, would have stopped it. The open
mirrored ones or simple inverted U shaped shields used elsewhere would
not. However, the important thing is the attenuation with distance. The
danger zone is only within 20cm of the lamp.

Colin Bignell

"Nightjar "cpb"@" "insertmysurnamehere wrote in message
...

The danger zone is only within 20cm of the lamp.
Or 30 cm if its twice as bright or 40 cm if its four times as bright.
There is no safe distance only a safe intensity*time.

Phil L wrote:
mark wrote:
Thought this might be of interest:

Not really, the silly bitch was sat with her face pressed against a table
lamp reading a book, what did she think was going to happen?

Nothing,if they were proper incandescent lamps.

Phil L
wibbled on Thursday 08 July 2010 13:43

mark wrote:
Thought this might be of interest:

Not really, the silly bitch was sat with her face pressed against a table
lamp reading a book, what did she think was going to happen?


I don't think she expected a good dose of UV-A!

Neither would I. I'm well aware that mercury lamps produce UV, but *I* would
have expected it to be filtered down to an acceptable level and regulated to
buggery (as so much that is irrelevant is regulated to buggery).

It's the lack of regulation that surprises me.

I presume the glass could either be doped or coated fairly trivially with
something to block UV without the need for a second glass envelope?

--
Tim Watts

Managers, politicians and environmentalists: Nature's carbon buffer.

F Murtz wrote:
Phil L wrote:
mark wrote:
Thought this might be of interest:

Not really, the silly bitch was sat with her face pressed against a
table lamp reading a book, what did she think was going to happen?

Nothing,if they were proper incandescent lamps.

There's a reason why MacDonalds have to have, 'WARNING - CONTENTS HOT' on
the side of their coffee cups, and that's to prevent braindead mutants
pouring boiling coffee straight down their throats, I can see the same thing
happening with everything else, on the bulb packaging it should clearly
state, 'WARNING, DO NOT EAT, OR STICK UP NOSTRILS AND TRY TO AVOID PROLONGED
EXPOSURE WHEN ONLY MILLIMETRES AWAY FROM LIT PRODUCT'

--
Phil L
RSRL Tipster Of The Year 2008

In article ,
Tim Streater writes:

Most people don't get as close to them as they do to desk or table
lamps. However, where there may be a risk, you can get UV-absorbing
sleeves to fit over them.

Yes, I figured that too, but in a large office there are plenty of such
overhead tubes. Or is it that the baffles underneath them, which reflect
a lot of the light, actually absorb the UV so the exposure is reduced?

Polycarbonate diffusers will absorb the UV, which also makes them
go yellow after some time, and eventually brittle. Modern fittings
don't use polycarbonate diffusers anymore because they're too
inefficient (lossy) - super high efficiency reflectors are now the
norm. I don't know what their perfomance is into the UV, but I
would guess they probably reflect UV just as well as visible light.

Incidently, inverse square law is for a single point source.
This doesn't really apply to office lighting, where
a) the individual light source is linear, not a point (until you
get a long way away), and
b) as you move away from a tube, the contribution from other
nearby tubes increases, and
c) the luminare optics can act to focus the light in such a
way that the intensity may even increase as you move away from
the luminare in some particular cases, although not at a distance.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

Phil L wrote:
F Murtz wrote:
Phil L wrote:
mark wrote:
Thought this might be of interest:
Not really, the silly bitch was sat with her face pressed against a
table lamp reading a book, what did she think was going to happen?

Nothing,if they were proper incandescent lamps.

There's a reason why MacDonalds have to have, 'WARNING - CONTENTS HOT' on
the side of their coffee cups, and that's to prevent braindead mutants
pouring boiling coffee straight down their throats, I can see the same thing
happening with everything else, on the bulb packaging it should clearly
state, 'WARNING, DO NOT EAT, OR STICK UP NOSTRILS AND TRY TO AVOID PROLONGED
EXPOSURE WHEN ONLY MILLIMETRES AWAY FROM LIT PRODUCT'

use as a dildo may result in UV burns to the vulva

On Thu, 08 Jul 2010 23:57:14 +0100, The Natural Philosopher
wrote:

Phil L wrote:
F Murtz wrote:
Phil L wrote:
mark wrote:
Thought this might be of interest:
Not really, the silly bitch was sat with her face pressed against a
table lamp reading a book, what did she think was going to happen?

Nothing,if they were proper incandescent lamps.

There's a reason why MacDonalds have to have, 'WARNING - CONTENTS HOT' on
the side of their coffee cups, and that's to prevent braindead mutants
pouring boiling coffee straight down their throats, I can see the same thing
happening with everything else, on the bulb packaging it should clearly
state, 'WARNING, DO NOT EAT, OR STICK UP NOSTRILS AND TRY TO AVOID PROLONGED
EXPOSURE WHEN ONLY MILLIMETRES AWAY FROM LIT PRODUCT'

use as a dildo may result in UV burns to the vulva

I read that as:- "uvula".

--
Frank Erskine

dennis@home wrote:


"Nightjar "cpb"@" "insertmysurnamehere wrote in message
...

The danger zone is only within 20cm of the lamp.
Or 30 cm if its twice as bright or 40 cm if its four times as bright.
There is no safe distance only a safe intensity*time.

There is a European recommended safe distance for domestic low energy
lamps of 20cm.

Colin Bignell

Andrew Gabriel wrote:
In article ,
Tim Streater writes:
Most people don't get as close to them as they do to desk or table
lamps. However, where there may be a risk, you can get UV-absorbing
sleeves to fit over them.
Yes, I figured that too, but in a large office there are plenty of such
overhead tubes. Or is it that the baffles underneath them, which reflect
a lot of the light, actually absorb the UV so the exposure is reduced?

Polycarbonate diffusers will absorb the UV, which also makes them
go yellow after some time, and eventually brittle. Modern fittings
don't use polycarbonate diffusers anymore because they're too
inefficient (lossy) - super high efficiency reflectors are now the
norm. I don't know what their perfomance is into the UV, but I
would guess they probably reflect UV just as well as visible light.

Incidently, inverse square law is for a single point source.
This doesn't really apply to office lighting, where
a) the individual light source is linear, not a point (until you
get a long way away), and
b) as you move away from a tube, the contribution from other
nearby tubes increases, and
c) the luminare optics can act to focus the light in such a
way that the intensity may even increase as you move away from
the luminare in some particular cases, although not at a distance.


It is, however, IMO a reasonable approximation when explaining why
commercial fluorescent tubes do not usually present the same propblems
as a low energy lamp in a table or desk lamp.

Colin Bignell

"Nightjar "cpb"@" "insertmysurnamehere wrote in message
...
dennis@home wrote:


"Nightjar "cpb"@" "insertmysurnamehere wrote in message
...

The danger zone is only within 20cm of the lamp.
Or 30 cm if its twice as bright or 40 cm if its four times as bright.
There is no safe distance only a safe intensity*time.

There is a European recommended safe distance for domestic low energy
lamps of 20cm.

To be safe from what?
Not UV.

dennis@home wrote:


"Nightjar "cpb"@" "insertmysurnamehere wrote in message
...
dennis@home wrote:


"Nightjar "cpb"@" "insertmysurnamehere wrote in message
...

The danger zone is only within 20cm of the lamp.
Or 30 cm if its twice as bright or 40 cm if its four times as bright.
There is no safe distance only a safe intensity*time.

There is a European recommended safe distance for domestic low energy
lamps of 20cm.

To be safe from what?
Not UV.

Go argue with the European Commission Scientific Committe on Emerging
and Newly Indentified Health Risks if you don't think so.

Colin Bignell

"Nightjar "cpb"@" "insertmysurnamehere wrote in message
...


Go argue with the European Commission Scientific Committe on Emerging and
Newly Indentified Health Risks if you don't think so.

No need, its obviously bull as two lamps at 20 cm have twice the intensity
as one.
Unless it is going to be a law I can safely ignore it and do it properly if
there is a danger to anyone from my lamps.

There is only one un-shaded CFL in my house and that has a toughened glass
surround so that's safe, the rest are up lighters.
I expect you get more UVA from a halogen capsule than a CFL anyway, but the
heat will put you off getting close.

dennis@home wrote:


"Nightjar "cpb"@" "insertmysurnamehere wrote in message
...


Go argue with the European Commission Scientific Committe on Emerging
and Newly Indentified Health Risks if you don't think so.

No need, its obviously bull as two lamps at 20 cm have twice the
intensity as one.

The recommendations are based upon realistic expectations of how people
are going to use the lamps and most people will only be using one that
close.

Unless it is going to be a law I can safely ignore it and do it properly
if there is a danger to anyone from my lamps.

You can ignore anything you like, but it is not always the safe option.

There is only one un-shaded CFL in my house and that has a toughened
glass surround so that's safe, the rest are up lighters.

So, you don't have any lamps that are likely to be relevant to the
recommendations. I did, as I was using a low energy lamp in a desk lamp
(now replaced with LED) that was close to my hand, was taking Amioderone
(now Beta blockers) and reacted to the UV (rash fading slowly).

I expect you get more UVA from a halogen capsule than a CFL anyway, but
the heat will put you off getting close.

I suspect the glass front will stop most of it, but that was a factor in
choosing an LED lamp rather than a halogen one.

Colin Bignell

Frank Erskine wrote:
On Thu, 08 Jul 2010 23:57:14 +0100, The Natural Philosopher
wrote:

Phil L wrote:
F Murtz wrote:
Phil L wrote:
mark wrote:
Thought this might be of interest:
Not really, the silly bitch was sat with her face pressed against a
table lamp reading a book, what did she think was going to happen?

Nothing,if they were proper incandescent lamps.
There's a reason why MacDonalds have to have, 'WARNING - CONTENTS HOT' on
the side of their coffee cups, and that's to prevent braindead mutants
pouring boiling coffee straight down their throats, I can see the same thing
happening with everything else, on the bulb packaging it should clearly
state, 'WARNING, DO NOT EAT, OR STICK UP NOSTRILS AND TRY TO AVOID PROLONGED
EXPOSURE WHEN ONLY MILLIMETRES AWAY FROM LIT PRODUCT'

use as a dildo may result in UV burns to the vulva

I read that as:- "uvula".

You read it any way you want mate!

"Nightjar "cpb"@" "insertmysurnamehere wrote in message
...


So, you don't have any lamps that are likely to be relevant to the
recommendations. I did, as I was using a low energy lamp in a desk lamp
(now replaced with LED) that was close to my hand, was taking Amioderone
(now Beta blockers) and reacted to the UV (rash fading slowly).

And you think that 20 cm is going to stop that?


I expect you get more UVA from a halogen capsule than a CFL anyway, but
the heat will put you off getting close.

I suspect the glass front will stop most of it, but that was a factor in
choosing an LED lamp rather than a halogen one.

The capsules don't have a glass front and neither do many of the fittings
for them.

In article ,
"dennis@home" writes:


"Nightjar "cpb"@" "insertmysurnamehere wrote in message
...


So, you don't have any lamps that are likely to be relevant to the
recommendations. I did, as I was using a low energy lamp in a desk lamp
(now replaced with LED) that was close to my hand, was taking Amioderone
(now Beta blockers) and reacted to the UV (rash fading slowly).

And you think that 20 cm is going to stop that?


I expect you get more UVA from a halogen capsule than a CFL anyway, but
the heat will put you off getting close.

I suspect the glass front will stop most of it, but that was a factor in
choosing an LED lamp rather than a halogen one.

The capsules don't have a glass front and neither do many of the fittings
for them.

Halogen lights have to have a means to contain exploding bulb fragments
unless they are using low pressure capsules, and often this is simply a
glass shield, either as part of the fitting, or part of the lamp.

However, halogen desk lamps have been implicated in skin cancer on the
hands. As a result, I think all new ones now have glass covers, but
also I think you'll struggle to find any of the small low pressure
capsules now which don't have UV-stop, in case they're used in fittings
without a glass shield. Sort of belt and braces for older fittings and
newer fittings.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]