CS 25.832 Cabin ozone concentration

(a)The aeroplane cabin ozone concentration during flight must be shown not to exceed –

(1)0·25 parts per million by volume, sea level equivalent, at any time above flight level 320; and

(2)0·1 parts per million by volume, sea level equivalent, time-weighted average during any 3-hour interval above flight level 270.

(b)For the purpose of this paragraph, “sea level equivalent” refers to conditions of 25° C (77° F) and 1 013·2 hPa (760 millimetres of mercury) pressure.

(c)Compliance with this paragraph must be shown by analysis or tests based on aeroplane operational procedures and performance limitations, that demonstrated that either –

(1)The aeroplane cannot be operated at an altitude which would result in cabin ozone concentrations exceeding the limits prescribed by sub-paragraph (a) of this paragraph; or

(2)The aeroplane ventilation system, including any ozone control equipment, will maintain cabin ozone concentrations at or below the limits prescribed by sub-paragraph (a) of this paragraph.