Sorry all- I do not think that the link I listed was correct. You may find
the information by opening the attached and clicking on the PDF for 261.24
(Toxicity Characteristics).
Regards,
David
-----Original Message-----
From: Ron Gedney <[log in to unmask]>
To: [log in to unmask] <[log in to unmask]>
Date: Tuesday, November 02, 1999 8:52 AM
Subject: RE: [LF] Impressions from Int'l Summit on LF Electronics Assemblies
>Dave,
>I get an error message trying to look at the referenced web site ... is
>it correct?
>
>-----Original Message-----
>From: David Suraski - AIM [mailto:[log in to unmask]]
>Sent: Tuesday, November 02, 1999 8:00 AM
>To: [log in to unmask]
>Subject: Re: [LF] Impressions from Int'l Summit on LF Electronics
>Assemblies
>
>
>Dear Lee (and all),
>
>I would like to comment on the TCLP data presented by my colleague, Karl
>Seelig.
>
>AIM did have CASTIN (Sn/Ag/Cu/Sb) bar, paste, and a crushed PCB that was
>assembled with the solder tested to TCLP test method 1311/6010. In
>addition, Sn/Cu and Sn/Ag alloys also were tested to these standards.
>You
>are correct in that none of these tests demonstrated a failure. This
>testing was performed by Environmental Science Services (ESS) Labs in
>Cranston, RI. These test results are available for review at your
>request.
>
>The above TCLP testing was performed to Federal standards. RCRA has
>determined that the following metals must be tested for by TCLP:
>Arsenic,
>Barium, Cadmium, Chromium, Lead, Mercury, Selenium, and Silver.
>Antimony
>has not been determined as an element that must be tested for by TCLP.
>A
>complete listing of the elements that fall under TCLP may be found at
>www.frwebgate.access.gpo.gov/cgi-bin/get-cfr.cgi .
>
>It is interesting to note that the report refers to drinking water
>standards. Drinking water has justifiably been assigned the most
>stringent
>standards of all classes of water. The standards are so strict, in
>fact,
>that if one was to run drinking water directly out of the tap through a
>drain and collect it for testing, it is likely that the water would fail
>to
>meet applicable standards. Drinking water and effluent wastewater have
>nothing to do with each other, as far as acceptable metallic levels are
>concerned. Wastewater from soldering operations is passed through waste
>streams to solid landfills, not through drinking water systems, and thus
>in
>judged by a different standard.
>
>I hope that this is helpful and I look forward to the lively debate that
>may
>ensue!
>
>David Suraski
>AIM
>-----Original Message-----
>From: Lee Wilmot <[log in to unmask]>
>To: [log in to unmask] <[log in to unmask]>
>Date: Monday, November 01, 1999 6:20 PM
>Subject: [LF] Impressions from Int'l Summit on LF Electronics Assemblies
>
>
>> Hello Everyone,
>>
>> While several subscribers have commented on the Minneapolis
>summit,
>> I have not seen in these comments, nor in the vast majority of
>papers
>> presented, much in the way of comparitive analysis of
>environmental
>> impact of the LF alternatives. There seems to be two specific
>areas
>> which are not being addressed - relative environmental toxicity of
>the
>> LF alternative, and relative recycleability of the end-of-life
>(EOL)
>> LF product. Perhaps the FEAR factor of a lead ban is driving such
>> abbreviated evaluations, but market share is a powerful driver
>too.
>>
>> 1. Comparitive leaching
>> These shortcomings are surprising since the alleged reason for
>> developing LF electronics assemblies is mainly environmental, even
>> though no data exists which links any adverse enviromental impact
>from
>> lead to electronic solder or assemblies. The only adverse lead
>impact
>> on the environment that we heard was that from Katsuaki Suganuma
>of
>> Osaka University. He showed that 1996 and 1997 monitoring data
>from
>> over 2000 waste storage areas in Japan showed 0.3%, or roughly 6
>sites
>> had lead levels in the groundwater (GW) of 1 ppb or more. There
>was no
>> linkage to waste electronic products presented. This data is
>> consistent with the 1991 data presented by Jeff Miller of the Lead
>> Industries Association (LIA) wherein two of 146 US municipal
>landfills
>> analyzed had GW contamination, and both were traced to industrial
>> waste disposal, a practice banned long ago in the US.
>>
>> The immobility of lead in the GW should not be surprising given
>the
>> insoluble precipitates that lead forms with sulfates. One reported
>> study of ancient Roman lead smelters revealed an estimated one
>yard
>> movement in two thousand years! By comparison, we heard of the
>high
>> levels of leaching of both silver and antimony from Ed Smith of
>K-Tec.
>> Specifically, of the eight solder alloys tested, antimony and
>silver
>> leached from all forms with all leach tests. The only presenters
>that
>> I recall addressing the toxicity of leachate from LF alternatives
>were
>> Karl Seelig of AIM Solder and Ken Snowden of Nortel. Of interest
>is
>> AIM's TCLP results (which were not in the paper or on their
>website)
>> which did not show leaching above TCLP hazardous waste levels for
>> either silver or antimony.
>>
>> 2. Recycling solution
>> The response to the toxicity concerns of LF alternative solders
>was
>> that even LF electronic assemblies need to be recycled. While this
>is
>> true, it is more critical that they be recycled because of the
>higher
>> relative mobility of the leachate from say silver. The
>implementation
>> issues for recycling electronic products is underestimated in my
>> opinion, and in Alan Rae of Cookson's presentation. I don't think
>that
>> too many in the industry understand the enormity of the reclaim
>cycle
>> that he described (from consumer to collector to dismantler to
>refiner
>> to processer to fabricator and back to the consumer). In fact,
>isn't
>> this the key issue in the proposed rev 3 of the WEEE directive?
>(i.e.
>> who's going to pay to collect WEEE?)
>> For nearly 20 years, it has been illegal to dispose of
>industrial
>> waste that tests "positive" for TCLP characteristics such as lead,
>or
>> silver, and the other six RCRA metals. Hence, both PWB and PWA
>mfgrs
>> in the US have had to recycle these byproducts, as they are
>prohibited
>> from being landfilled (or incinerated) at non-TSD (treatment,
>storage
>> or disposal) facilities. These restrictions have not applied to
>> consumer wastes, but there's been successful consumer recycling
>> programs for used oil, newspapers, certain plastics, aluminum
>cans,
>> etc. No reason why one for consumer electronics couldn't be
>started.
>>
>> 3. Recycleability
>> A key area in selecting a LF alternative is whether the EOL
>> products can be recycled at the same or higher rate than the
>present
>> SnPb products area. What was quite surprising to hear from Ken
>> Snowden's presentation is that major copper smelters in both North
>> American and Europe will not take material with more than 20 ppm
>> bismuth in it! This could be a real show stopper for solders
>> containing Bi, unless shipping these EOL products to Japan is
>done, as
>> Japanese smelters reportedly do not have such restrictions.
>>
>> Unpopulated PWBs are roughly 20% Cu and 1% Pb. We heard that
>PWAs
>> are about 3% Pb. Assuming that the components and added solder
>double
>> the weight of the PWB, the PWA would be about 10% Cu. The 3% Bi
>solder
>> that Panasonic developed would therfore, result in about 2500 ppm
>Bi
>> on the PWA. After EOL, where would these WEEEs w/Bi be recycled if
>the
>> major Cu smelters in N.America and Europe won't take them?
>>
>> 4. Other environmental issues
>> We heard one paper on the technical abilities of an immersion
>> silver finish on PWBs. However, PWB fabricators must meet an
>extremely
>> low discharge limit for silver. Typically 0.05 to 0.15 ppm, much,
>much
>> lower than lead and other PWB metals. Given the high aquatic
>toxicity
>> of silver, PWB shops will have to use extreme care to prevent
>wiping
>> out the biological activity of the sewer authority to which they
>> discharge.
>>
>> The International Chamber of Commerce's (ICC) Business Charter
>for
>> Sustainable Development contains 16 principles. Based on what I
>heard
>> and read the the Minneapolis summit, I'm not sure that the
>following
>> have been addressed thoroughly with the LF presentations that I
>heard:
>>
>> "6. Products and services
>> To develop and provide products or services that have no undue
>> environmental impact and are safe in their intended use, that are
>> efficient in their consumption of energy and natural resources,
>and
>> that can be recycled, reused, or disposed of safely."
>>
>> "9. Research
>> To condust or support research on the environmental impacts of
>raw
>> materials, products, processes, emissions and wastes associated
>with
>> the enterprise and on the means of minimizing such adverse
>impacts."
>>
>> "13. Transfer of technology
>> To contribute to the transfer of environmentally sound
>technology
>> and management methods throughout the industrial and public
>sectors."
>>
>> To sum up my concern, the Assembly breakout group's #1 concern/
>> roadblock was as follows:
>>
>> "Insure that the alloy of choice won't be banned in ten years"
>>
>> Succintly stated. In my opinion, the LF development efforts have
>been
>> focused on the technical issues of melting point, solderability,
>> wetability, reliability, etc, which they need to, but they also
>need
>> to focus on the ICC principles stated above. From what I heard,
>many
>> of the technical issues have been addressed, but few of the
>> environmental impacts have been.
>>
>> Nortel's SnCu solder holds promise if high temperature
>substrates,
>> HASL oils and components can be developed, as does Toshiba's SnZn
>> solder if application issues can be developed. I'm not comfortable
>> that solders containing silver, antimony and bismuth wont' be
>banned
>> in ten years if lead is banned now. Lee
>Wilmot
>> HADCO
>Corp
>>
>> NOTE: These views are mine, and not necessarily those of my
>employer.
>>
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>>IPCWorks -October 25-28 featuring an International Summit on Lead-Free
>Electronic
>>Assemblies.
>>Please visit IPC's Center for Lead-Free Electronics Assembly
>>(http://www.leadfree.org ) for additional information.
>>For technical support contact Gayatri Sardeshpande [log in to unmask] or
>847-790-5365.
>>################################################################
>>
>
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>with following text in the body:
>To subscribe: SUBSCRIBE Leadfree <your full name>
>To unsubscribe: SIGNOFF Leadfree
>################################################################
>IPCWorks -October 25-28 featuring an International Summit on Lead-Free
>Electronic
>Assemblies.
>Please visit IPC's Center for Lead-Free Electronics Assembly
>(http://www.leadfree.org ) for additional information.
>For technical support contact Gayatri Sardeshpande [log in to unmask] or
>847-790-5365.
>################################################################
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