Brian: For the record, Panasonic, along with most other TV manufacturers, eliminated lead from the panel glass some time ago. When we did still use lead in the panel, I understand that it was in the 3% range.
I am now checking with out glass suppliers to obtain more detailed information and will hopefully be able to provide this soon.
David A. Thompson
Director
Corporate Environmental Department 3G-4
Matsushita Electric Corporation of America
One Panasonic Way
Secaucus, NJ 07094
TEL: (201) 271-3486
FAX: (201) 348-7686
NEW ADDRESS: [log in to unmask]
PS Brian: Sorry for the duplication. My original transmission did not go through.
-----Original Message-----
From: Brian Ellis [mailto:[log in to unmask]]
Sent: Tuesday, December 09, 2003 5:22 AM
To: [log in to unmask]
Subject: Re: [LF] Amount of Pb in a "typical" motherboard
Chuck
There are some anomalies in your discussion, IMHO.
I'll go along with you on the funnel (1 -9 lbs), but most of the lead is
in the front screen. An 18" screen has a screen size of 36 x 30 cm and
is about 15 mm thick (monitors are thicker than TVs, as they are used
closer to the user's face and radiation levels have to be lower). That
gives a volume of 1,620 cm3. I believe the PbO content of the glass is
about 30% v/v, = 480 cm3. The density of PbO is ~9 (depends on the
crystalline form), of which ~90% is lead, so that would give about 4 kg
or nearly 9 pounds for the screen faceplate alone.
In fact, something like 20% of the weight of a TV or CRT mmonitor is
lead. Anyone who has handled a 28" TV CRT, without the focus and
deflection coils knows it is bloody heavy, on its own. The guts are made
up mostly of very thin nickel sheet metal and have a total weight,
including the shadow mask, of <100 g. The rest is practically all lead
glass.
Chuck Dolci wrote:
> Here is some data that the EIA gathered on lead in monitors.
>
> 3% of US lead consumption is oxides in glass and ceramics (includes CRTs
> and other uses)
> Reduced to minimum amount for effective x-ray shielding; encased in
> glass matrix
> Found in 4 major areas of CRT (range 8” - 35” and above)
> Funnel Glass 1 - 9 lbs
> Frit (Solder Glass)- 0.057 - 0.215 lbs
> Panel Glass - used by 25% of industry 0.2 - 2.0 lbs
> Neck Glass 0.027 - 0.054 lbs
>
> Range of total lead in CRTs: 1.08 -9.27 lbs
> Average CRT: 18”, 2.16 - 2.59 lbs lead
>
> I assume TVs have slightly more than monitors because they have tuning
> and audio circuitry that monitors don't.
>
>
> According to "Alternative Technologies for Surface Finishing
> (EPA/744-R-01-001) June 2001," available at www.epa.gov/dfe
> lead comprises 0.7% total weight of a typical printed circuit board
>
> Chuck Dolci
>
> Hal P Abel wrote:
>
>> Clark,
>>
>> The big hitter is the CRT monitors. I believe that they contain 10 Lbs of
>> lead.
>>
>>
>>
>> Hal
>> Abel
>>
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