A Ban on Farting?

Apparently judicial officials in Malawi disagree as to whether a legal prohibition on 'fouling the air' makes it an offence to fart in public. One argues that it is, citing public decency, which makes it look like the law - if interpreted in this way - violates Mill's harm principle (though Mill himself had some rather incongruous things to say about public decency). It's hard to say that farting (unlike air pollution) really harms others - and, even if it does, that need not justify a ban.