From what I have read and experienced, unless you are in a small confined area like baking out a car, you cannot fail from second hand smoke. I stopped smoking for about 9 months and I worked with a guy that smoked everday in a 12x12 room and I never failed for second hand smoke. I also rode in the car to a concert when friends were smoking, so I made them roll down the windows and I never failed from that second hand smoke either.