Gordon

Your essay is too long to reply point by point. My main concern is with
ozone depletion. Most bromo-organics and molecular bromine reaching the
ozone layer will cause something like 50 to 70 times as much ozone
depletion as chloro-organics (e.g., CFCs), halogen molecule for halogen
molecule. Methyl bromide, which I mentioned earlier, is a case in point.

OTOH, bromocarbons usually have a shorter atmospheric residence time
than the corresponding chlorocarbons, as the weaker bond strength
between the C and Br atoms make them more subject to decomposition in
contact with atmospheric hydroxyl groups. This may produce a successive
simplification of the molecules, some of which will produce ionic
bromides which will mostly rain out, often as hydrobromic acid.

A typical residence time of a bromocarbon would be a matter of days. For
example, depending on the hydroxyl concentration and some other factors,
that of n-propyl bromide (1-bromopropane) is 10 - 25 days. The transport
time of molecules to the tropopause is weather, latitude and
season-dependent, fastest in violent thunderstorms (an hour or so), then
in the intertropical convergence zone (one to six days) and least in the
polar regions (months). In the tropics, the tropopause is already in the
ozone layer, but there are several transtropopausal mechanisms that can
effect a transfer of molecules more or less rapidly into the
stratosphere, where the bulk of ozone depletion occurs. One atom of
elemental bromine in the ozone layer will catalyse the mean destruction
of an estimated 1 to 2 million ozone molecules. The UNEP Science
Assessment Panel of the Montreal Protocol has noted a stabilisation of
chlorine levels in the ozone layer, but bromine levels are still
increasing, despite controls on halons and some other bromo-organics.

My main concern is therefore that ALL bromocarbons should be used with
circumspection. As long as flame retardants are bound in a polymer
matrix, there is no danger. Allow the bromine compounds to be pyrolysed,
and a veritable soup of organic and inorganic compounds may be released.
Some of these will inevitably reach the ozone layer, even if it is small
in percentage terms. This percentage will be highest in the tropics and
lowest at the poles, but will still be significant at mid-latitudes.

Apart from that, my secondary concern is the local effect close to
places where uncontrolled incineration takes place. There is no doubt
that most bromides and simple bromocarbons are very phytotoxic and
zootoxic to lower organisms (this is why bromine compounds are used in
smaller quantities in swimming pools and why methyl bromide is used as a
fumigant and pesticide). It is known that haloacetic acids are
detrimental to the growth rate and crop yield of plants of the order
leguminosae, as they inhibit nitrogen-fixing nodule formation, even in
ppb atmospheric concentrations. This, in turn, will lower soil fertility
with crop rotation. Trichloroacetic acid is the most common cause, but
tribromoacetic acid would be just as effective and probably more so,
although, of course, chlorine is more common than bromine.

The effect on humans and higher animals of various common bromine
compounds is fairly well documented. They are all toxic and many
bromocarbons are neurotoxins and reproductive toxins. Unfortunately, we
know little of the effects of most of the more complex molecules. We
have seen that iso-propyl bromide is a cause of reproductive problems in
both sexes in recent years and n-propyl bromide is a suspected
neurotoxin with several anecdotal cases amounting to paralysis occurring
in industry, despite precautions taken and low exposure levels.

I therefore suggest:
1. if other SUITABLE molecules are available for a job, brominated
molecules should be the last choice
2. adoption of the precautionary principle where bromocarbons are used
and restrict emissions to a minimum
3. adoption of the precautionary principle where bromocarbons are used
and avoid contact between bromocarbons and living organisms of all types
4. specifically, avoid using bromocarbons as PCB flame retardants where
other types are suitable.

Brian


Davy, Gordon wrote:
> In recent postings Brian Ellis has challenged of the use of brominated
> fire retardants in electronic products and the IPC's support for this
> practice. He says, "Emissions of incinerated halogen-containing
> laminates may contain some highly hazardous and polluting substances, as
> shown by scientific studies." He is "perplexed why a probably [emphasis
> added] environmentally favourable action (Br-free laminates), with
> scientific backing, should be pooh-poohed by the IPC" "when we do have
> non-brominated substitutes already available".
>
> He says that while properly incinerated waste (including brominated
> flame retardants) is "relatively harmless", improperly controlled
> combustion produces many noxious chemicals. That is true, he points out,
> whether what is being burned is a discarded TV or any other debris.  A
> lot of what passes for incineration is totally uncontrolled: fires in
> landfills and municipal incinerators, few of which, he says, are
> suitable for the job. He is "pretty sure" that "99%" of incineration of
> used equipment (and, presumably other refuse) is not properly
> controlled, that "vast quantities of highly toxic and polluting
> compounds are emitted as a result," and that "What the effect of these
> compounds on crops, livestock and humans is relatively unknown but I'm
> sure it is not negligible."
>
> He also says that even though many of these compounds are also produced
> by natural means, humans should not make more. He gives the example of
> methyl bromide, three-fourths of which is of human origin. It isn't
> clear from his example as to whether he would permit adding to the
> natural sources by some lower amount, such as one percent. Perhaps he
> would be willing to tell us the highest permissible ratio of
> anthropogenic to natural production he would permit.
>
> Finally, he even seems to suggest that laminates containing bromine
> "should be considered as a source of molecular bromine for recycling."
> (I'd be interested in the cost-benefit analysis he used to arrive at
> that recommendation.)
>
> Although not always agreeing with Brian's postings over the years, I
> have benefited from reading them (as I'm sure many other subscribers
> have), and frankly I am perplexed as to why he would take this stand. I
> think that he hasn't supported his case, and that the IPC leaders made
> the proper decision. Isn't he really saying that since incinerating
> halogen-containing substances may create a public health hazard,
> manufacturers who have been putting any such substance into any product
> that might get incinerated should be coerced by government edict into
> switching to a substitute if one exists? That's my interpretation of
> what I read, including his phrase "beholden to provide means of
> harmlessly destroying them, at end of life."
> Until his most recent posting, I assumed that he was concerned with
> dioxins but now, I'm not so sure. For all he has shared with us so far,
> it isn't clear why he is picking on halogenated flame retardants, since,
> as he acknowledges, burning other debris also produces pollutants. (You
> don't need scientific studies to tell you that.) What needs to be
> established, among other things, is why burning a laminate with bromine
> in it is worse. I'm guessing that what he is really concerned about is
> not pollutants in general but those which come from improper combustion
> of refuse containing bromine, and that he believes that improper
> combustion of bromine-containing electronic products is worse for the
> environment than improper combustion of those products without bromine.
> How much worse, we don't know, but we can agree that it is undesirable
> to be producing and emitting any pollutant into the environment if it
> can be avoided.
>
> I would like to suggest that before we offer a solution to a problem, we
> try to get an agreement on what the problem is. Perhaps Brian could
> share more; saying "probably" and "pretty sure" suggests he may lack
> some confidence in his data or his conclusions. Also, it is worth
> recalling that discarded electronic products constitutes only about one
> percent of the total municipal solid waste, so one really needs to show
> that a proposed solution will make a noticeable improvement, i.e., out
> of proportion to this low percentage. (In fact, with the WEEE
> legislation in Europe and similar restrictions being considered by many
> US state legislatures, the percentage is destined to drop.)
>
> Not knowing the amount and types of pollutants being produced by
> uncontrolled incineration of municipal solid waste or the estimated
> number of casualties these emissions are causing complicates performing
> a cost-benefit analysis of the problem and the proposed solution (the
> discussion is probably more suitable for the halogen-free forum than
> this one), but I think that some progress is possible. Wouldn't you
> think that if many people were experiencing clinical symptoms due to
> pollution from incinerated refuse we'd have heard about it from the
> environmental activists? Maybe Brian can get some data from people whose
> job it is to dispose of waste or to deal with public health.
>
> However, if the problem really were as serious as implied by his
> willingness to force people to abandon brominated fire retardants in
> spite of their usefulness, I still wonder why he proposes the solution
> he does. That is, if incineration of halogenated materials in electronic
> products were adding significantly to human suffering, it is hard to see
> how, even if their use were eliminated tomorrow, the proposed
> prohibition would bring about noticeable relief for many years. People
> incinerate old products, not new ones.
>
> (As a tie-in with lead, the lack of logic for forcing people to keep
> halogens out of electronic products is similar to what I have observed
> for forcing people to pay extra to keep electronic products out of
> landfills. Given that landfills - and soil along roadways - already
> contain lots of lead, how would prohibiting the landfilling of solder
> and CRTs help prevent the alleged lead contamination of drinking water?
> Lots of contributors to this forum have expressed favor for this
> proposal, but so far the only support I have seen is not a cost-benefit
> analysis but vague references to sustainability, a separate argument.)
>
> Since I believe that that the amount of additional suffering being
> caused by improper combustion specifically of discarded
> bromine-containing electronic products is too small to be calculable, I
> wonder whether his fix might even have a net negative effect. In his
> reference to substitutes he implies (without actually claiming) that
> they are suitable, i.e., that they don't themselves create other
> problems (such as providing poorer fire retardancy or reducing product
> reliability). There are documented cases of fires - and suffering -
> being caused by faulty TV's.
>
> If I am wrong, and improper combustion of waste is causing measurable
> misery, there are still better remedies, such as firing for negligence
> the manager of an incinerator or landfill that is found to be emitting
> pollutants above some limit. If an incinerator is incapable of proper
> operation, it needs to be shut down, just as John Snow removed the
> handle from the pump to prevent people from contracting cholera from
> cesspool-polluted water. (See the story at
> http://www.ph.ucla.edu/epi/snow/removal.html.)
>
> Although the cholera analogy isn't entirely apt, it seems to me that
> allowing improper incineration to continue while awaiting the day when
> no more halogenated materials are entering the waste stream would be
> like leaving the handle on the pump while undertaking a public works
> project to connect every house to a sewer system and eliminate every
> cesspool. Unlike the analogy, for which there was a clear need for a
> long-term fix (sewer), Brian acknowledges that with properly operating
> incinerators, halogenated products in the waste stream are not a public
> health hazard. Thus, forcing the use of substitutes for this reason adds
> no value. It may make things worse.
>
> The fix supported by Brian may be "green" (i.e., approved by
> environmental activists who purport to speak for the best interests of
> us all and who reserve for themselves the right to confer this
> designation as they see fit). However, it seems to me that, without
> further explanation, prohibiting brominated flame retardants in
> electronic products out of a concern for their possible improper
> combustion is neither necessary nor sufficient.
>
> Gordon Davy
> Note new as of May 28: [log in to unmask]
> 410-993-7399
>
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