As chemical weapons , they are classified as weapons of mass destruction by the ORGANIZATION@1 according to ORGANIZATION@2 Resolution NUMBER@1 -LRB- passed in April NUMBER@2 -RRB- and their production and stockpiling was outlawed by the MISC@1 of NUMBER@3 ; the MISC@1 officially took effect on April NUMBER@4 , NUMBER@5 .

Since they are chemical weapons , they are classified as weapons of mass destruction by the ORGANIZATION@1 according to ORGANIZATION@2 Resolution NUMBER@1 .
