It also includes your breath after having partaken ¼ of a unit of any
alcoholic beverage, includin beer and wine.
As usual, the EU has, by its definition, demonstrated its habitual
scientific ineptitude. It takes no notice whatsoever of the effect a VOC
has on the environment. Not all VOCs photoreact with NOxs in the same
way. The directive that Graham quotes applies particularly to solvents.
Some alkane or alkene solvents, as well as most cyclic ones, react
severely, where others have hardly any effect. For example, "white
spirit" and terpenes are bad but perchloroethylene has almost no effect,
but the permitted stack concentrations are identical for all of them.
Plumb crazy, again.
The US regulations and exemptions on VOCs depend largely on which lobby
can cry the loudest, especially in CA.
On neither side of the Atlantic is the legislation based on sound
science. (Where have I heard that before?)
Brian
Graham Naisbitt wrote:
> David
>
> Fluxes are used for essentially 2 purposes: one to remove surface oxides and
> to facilitate good wetting and second as a heat transfer medium.
>
> You then ask: "do they burn off...during the soldering process" - to quote
> my good friend Doug Pauls: "It depends".
>
> It depends on the type of flux being used. If it is a no-clean flux, then it
> is the flux manufacturers intention that the residues - and ALL fluxes leave
> residues - shall be volatilised off the surface by the correct amount of
> heat relative to residue volume. Of course, if you have areas (i.e. topside
> in wave soldering) that do not see the correct temperature for the desired
> time, then they will remain behind and might cause you some reliability
> issues when in the field.
>
> Some other rosin based, dare I say classic, fluxes, are sometimes designed
> to be left on the surface, or at least may be left behind in the knowledge
> and comfort (well, on a wing and a prayer sometimes!) that they will be
> cleaned off afterwards.
>
> VOC's:
>
> As defined by ³Council Directive 1999/13/EC of 11th March 1999:
> 17. volatile organic compound (VOC) shall mean any organic compound having
> at 293.15 K a vapour pressure of 0.01kPa or more, or having a corresponding
> volatility under the particular conditions of use
>
> As defined by ³Council Directive 1999/13/EC of 11th March 1999:
> Organic compound shall mean any compound containing Carbon and at least one
> or more of hydrogen, halogens, oxygen, sulphur, phosphorous silicon or
> nitrogen
>
> As defined by ³Council Directive 1999/13/EC of 11th March 1999:
> 9. Šemission shall mean any discharge of volatile organic compounds from an
> installation into the environment. Šinto air, soil and water as well as
> solvents contained in any products. They include uncaptured emissions
> released to the outside environment via windows, doors, vents and similar
> openings.
>
> VOC Controls:
> USA = Tax on solvents BUT Tax-Free solvents on EPA list
> EU = Anything with a vapour pressure that is >0.01kPa @293.15K
> This includes Whisky, Gin, Brandy, VodkaŠbut not beer and wine!
>
> I hope this helps
>
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