Here is some WW2 British Army equipment from my collection as issued to the normal soldier:
First, an early war respirator, the carrying bag (usually worn in front of the chest), two boxes of decontamination ointment, an envelope of face shields (cheap disposable safety shields made of cellophane to protect the eyes while decontaminating), a wad of cotton waste for cleaning and a anti-dimmimg kit (the green cylinder, to prevent fogging of the lenses of the mask).
The next one shows the light weight respirator issued post 1943, the carrying bag was either worn over the shoulder or attached to the P37 web belt.
The soldiers were also issued a gas cape made of linseed oil treated canvas, but these are very hard to find today and usually quite expensive. The gas cape was often used as a rain cape (though strictly forbidden), because the normal groundsheet/ cape made out of rubberised canvas issued to the soldiers was too small and only protected the upper body.
Jan