Excise exemption for white phosphorus used in manufacture of specified phosphorus compounds, subject to prescribed procedural compliance. Exempts white phosphorus within Chapter 28 when used to manufacture phosphorus trichloride, phosphorus pentasulphide or trimethyl phosphite from the whole of the excise duty leviable thereon; if such use is outside the factory of production the procedure in Chapter X of the Central Excise Rules, 1944, must be followed.