propos intern commiss protect rhine pollut intend supplement annex iv convent protect rhine chemic pollut sign bonn decemb intern commiss protect rhine pollut regard convent protect rhine chemic pollut sign bonn decemb regard articl thereof regard propos june tabl baden switzerland intend add annex iv convent limit valu mercuri discharg chlor alkali electrolysi establish propos contract parti convent annex iv convent decemb supplement respect mercuri gt pic file quot quot gt gt pic file quot quot gt gt pic file quot quot gt limit valu industri paper steel coal fire power station propos intern commiss stage meantim govern fix emiss standard mercuri autonom accord articl convent standard account technic mean stringent nearest compar limit annex iv pursuant articl convent provis enter forc unanim accept contract parti convent contract parti notifi adopt govern swiss confeder acknowledg receipt notif