VPD papers

I hope no one is using VPD, as far as I'm aware its use is banned in the
USA, and I wouldn't recommend it.  Cyclohexylamine carbonate (the
chemical used in vapour phase deacidification) does not fully deacidify
nor does it produce a base reserve and is therefore not very useful as a
deacidificant. Furthermore, cyclohexylamine sulphate (the product of the
deacidification reaction) itself becomes slightly acidic in humid
conditions.  The reason for its ban is its chemical similarity to the
cyclamates (artificial sweeteners) which when fed to rats in huge doses
caused cancer.

Tina Groenevelt
Archive Conservator
Greater London Record Office

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                  Conservation DistList Instance 8:34
                 Distributed: Monday, November 7, 1994
                        Message Id: cdl-8-34-003
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