From: peter@tsto.co.uk   
      
   The UK Government is proposing to limit the concentration of acids and   
   some other chemicals which home users with licenses can possess to the   
   following:   
      
   Hydrogen Peroxide        35%   
   Nitric acid            10%   
   Sulfuric acid            40%   
   Chlorates and perchlorates    40%   
   Ammonium nitrate        16%N   
      
   Note this is with a license, without a license the concentrations are lower.   
      
   Having to get a license is one thing, but making licenses unavailable is   
   quite another. I am going to reply to the consultation, and so - does   
   anybody know of any legitimate hobby/home uses for any of these   
   chemicals at high concentration?   
      
     - Hydrogen peroxide at >35% is mostly the province of rocket fuel,   
   though 50% is used in some home chip-making techniques (yes, people do   
   make microchips at home - record so far is 1,200 transistors afaik).   
      
      
     - There are quite a few uses for strong nitric acid at above 10%:   
   50% passivating stainless   
   50% iron particle removal from machined nickel alloy parts  safety critical   
   50%+ precious metal recovery and refining   
   50% unknown metal testing   
   70% gold test kits   
   86%+ (fuming) decapping microchips   
      
      
     - The only use I have come up with so far that needs >40% sulphuric is   
   for making acid pirhana solution for cleaning glass and ceramics. The   
   commercial 98% is undoubtedly useful for topping up baths for anodising,   
   electroplating and electroforming, but it could be argued that 40% is   
   sufficient here - not sure that is always true though, if you get in a   
   mess sometimes 98% is the only thing which will do.   
      
      
     - Chlorates and perchlorates at >40%. Chlorates were used as   
   weedkillers until the EU banned them on the grounds that nobody had   
   shown them to be safe for the environment (nobody had showed them to be   
   particularly dangerous either, and quite a few gardeners still swear by   
   sodium chlorate), but this may have actually been a reaction to the   
   sugar/chlorate explosive of boys pranks and more dangerous uses.   
      
   They are also used in theatrical flash mixtures and for photography.   
      
   Plus a lot of fireworks components like stars will have >40% perchlorate.   
      
      
     - Ammonium nitrate at >16%N ??   
      
   Peter Fairbrother   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)