Can you set off smoke alarms with electronic cigarettes?

Do e-cigs really set off smoke alarms? Well, the short answer is yes, but it is not so black and white. You have probably never heard of anyone ever complaining that their e-cigarette was setting off their home smoke alarm or anything of the type, and that is more the likely the case for everyone. This discussion has been had over various boards like Reddit or other online forums and you can even find a multitude of YouTube videos where people blow vapor directly into the smoke alarm and it goes off. So how come water vapor is setting off smoke alarms?

The answer is not so complicated, but requires a basic understanding of all the different types of smoke & fire detectors. Most commonly used smoke detectors in homes and restaurants use an optical photoelectric type sensor that is set off when smoke obstructs the air in front of it. This means you can throw water or any fine type sand or dirt into the vent and it will also set it off. These are the cheaper type smoke detectors you can purchase at any hardware store for example. Therefore, if a thick cloud of vapor is blown into the detector, it can be enough to obstruct the optical mechanism and set it off, without any actual presence of smoke.

Another similar type of technology is  the air ionization detection system that is triggered when smoke enters and changes the ions present in the air surrounding the detector. This system is also very popular and has a similar function and response time time to an optical detector. However, things get a bit more complex when we look at all the other types of alarms, such as CO2 carbon monoxide detection. These types of systems will measure how much CO2 emission is present in the surrounding air, but are not typically used to alarm of fires due to the slow response time.  There are even more systems such as air-sampling and temperature triggers which are reserved for controlling sprinkler systems and such.

With that said, the majority of places will use the basic cheap optical detectors for one very important reason. They detect possible smoke and fire faster than most other systems, and are therefore used in conjunction with other advanced fire protection installations. So, almost anywhere you may be, you will most likely be surrounded by optical or ion smoke detectors, but does that mean your e-cigarette will set them off if you use it indoors?

Should You Be Worried About Setting Off Smoke Alarms By Vaping?

First, let’s say that if you are asking yourself this question, you might be vaping in a location where it may be frowned upon, and most would usually suggest to be respectful in not doing so. However, nobody wants to be setting off smoke detectors and their loud beeps in any situation. In the end, it is unlikely to set off these detectors unless you are really close to one, so just be smart and don’t vape next to smoke detectors. The chances of setting off smoke detectors at home are close to none unless you are standing right under it. Because vapor is simply the form of water molecules evaporated with heat, they quickly dissipate and don’t linger in the air like smoke does. That’s why it never happened to you yet, and why you probably never heard anyone mention it. So, if anyone asks, yes you can set of a smoke alarm if vapor is going directly into it, but in any other case, not likely!