A breath sampling device includes a main housing having an input chamber, a first output chamber, and a second output chamber integrally formed therein where the input chamber and the first output chamber are coupled via a first port and the input chamber and the second output chamber are coupled via a second port, and a self-sealing apparatus within the second output chamber configured to seal at least an exhaust port of the second output chamber when a predetermined amount of initial waste air fills the second output chamber. The main housing can be configured to redirect a portion of air blown therethrough towards the output chamber via the first port when the self-sealing apparatus at least seals the exhaust port. Other embodiments are disclosed.
