When travelling by aeroplane, during checkin at the airport, you are asked to declare if any flammable liquid is in the

[answerhappygod]

When travelling by aeroplane, during checkin at the airport, you
are asked to declare if any flammable liquid is in the luggage or
hand carriage. Why is this question asked by the airline? (Explain
in scientific terms what would happen to the flammable liquid). The
airline must be having the experimental evidence about the
flammable liquid. What experimental evidence do you think they may
have and how can you repeat that experiment to obtain that
result?