| Meaning of “ultra light” | “Ultra light” is a historical marketing-style description, not a separate scientific cigarette category with a universal definition. | The term alone does not establish a product’s emissions, nicotine delivery, or health risk. |
| Canadian labelling context | Canadian tobacco rules restrict misleading representations about a tobacco product’s effects on health. “Light” and “mild” descriptors have been prohibited on cigarette packages and in advertising. | “Ultra light” should not be treated as an official Canadian safety rating or a reliable measure of lower exposure. |
| ISO 3308 puff volume | The standard machine-smoking regime uses a puff volume of 35 mL per puff. | This is a controlled laboratory setting, not a measurement of how much a person actually inhales. |
| ISO 3308 puff timing | The standard regime uses a 2-second puff once every 60 seconds. | Changing puff volume, duration, or frequency can change measured machine yields. |
| Ventilation during ISO testing | Under the ISO routine method, filter ventilation holes are not deliberately blocked as they are in some more intensive machine-testing protocols. | Ventilation can dilute smoke drawn by the machine and affect reported yields; it does not mean a smoker will inhale the same amounts. |
| What machine yields represent | Machine tests can measure emissions such as nicotine, tar (nicotine-free dry particulate matter), and carbon monoxide under the specified conditions. | Results describe emissions under that test method; they are not a direct prediction of an individual’s exposure or disease risk. |
| Canadian Intense testing | Health Canada’s Canadian Intense smoking regime uses 55-mL puffs every 30 seconds and blocks filter ventilation holes. | Its conditions are more intensive than ISO 3308’s routine regime, so results from the two methods should not be compared as if they were produced identically. |
| Health interpretation | Machine-measured yields and “light” or “ultra light” descriptions do not establish that a cigarette is safe or that switching reduces health risk. | All combustible cigarettes expose users to harmful substances; no machine-test result makes smoking safe. |