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DIY Vehicle Interior Cigarette Smoke Residue Test Kit
DIY Vehicle Interior Cigarette Smoke Residue Test Kit
The world's first and most sensitive DIY rapid cigarette smoke residue test kit for pre-owned, rental, and commercial vehicles. Knowsmoke's patented design and sample collection system offers instant, precise, and affordable results for anyone concerned with cigarette smoke contamination in their next vehicle

Alternative solutions are overly complicated, time-consuming, and impractical. Skip the 10-14 day wait for lab results and uncover the smoke history of any vehicle in minutes. Suspect smoke but can't smell it? Don't worry. Knowsmoke deploys the same proven lateral flow immunoassay technology found in medical labs, with a nicotine/cotinine detection threshold of 0.2 ng/ml. All testing materials are provided. Not recommended for in-home use on common household surfaces. Single-use.
$89.00 $49.99
  • Rapid Detection: Uncover toxic cigarette smoke residue within vehicle upholstery within minutes, even if it's not detectable by smell. No lab testing required.
  • Accurate & Safe: Our tech uses a trusted scientific method to accurately isolate and detect cigarette-specific particles.
  • Portable & Discreet: Perfect for on-the-go! Take Ion with you before you rent or buy.
  • Easy To Use: Just point and press! Scan results with the Knowsmoke app to ensure accuracy.
  • US & EU Patent-Pending: World's first rapid cigarette smoke residue test kit, ultra-sensitive for unparalleled accuracy.
  • Where to Test: For best results, apply test kit to fabric headliner or driver's headrest.
Over 10,000 test kits sold!

  • Size: 38 x 38 x 153 mm
  • Lightweight and portable: 75 grams

  • Liquid Ingredients: Aqua, Polyoxyethylene (20) sorbitan monolaurate, Cetrimonium bromide , 2- hydroxypropane-1,2,3-tricarboxylic acid, 2-Hydroxypropanoic acid, 2-[4-(2,4,4-trimethylpentan-2- yl)phenoxy]ethanol, Sodium dodecyl sulfate, Gold nanoparticles.
  • Ion is single-use, non-toxic, and recyclable.

  • If your purchase doesn’t live up to your expectations within 30 days of receiving the product then you may return it for a full refund.
  • Returns must be unused, in the state you received them, and back in the original packaging.
  • We’ll pay for shipping back to us. Just send us an email to within 30 days of receiving your product. Speed things up by sending your Order ID and the reason for returning your order(s). This won’t affect your return in any way, but it’s really helpful feedback for us as we continually work to improve all of our products!

How can I see Ion in person since it’s not offered in physical stores?

  • Since we only sell online, we’ve created a very low pressure, 30-day return period for you to order and check out your purchase. This time allows you to see the product in person without any risk as we’ll pick up the shipping costs both to your home and back to our facility if you choose to return your order. If you have additional questions related to our return policy, click here.
  • If you’ve purchased our products from one of our partnered retailers, please review their return policy for guidance. We do not honor returns for products purchased from our licensed distributors.

How to use Ion in 3 simple steps.
Step 01
Apply the base of the test kit firmly against the headliner, creating a 360° seal.
Step 02
In a single motion, press up to inject Ion’s liquid solution into a vehicle’s headliner and hold for 10 seconds. Using negative pressure, a sample is extracted for analysis.
Step 03
Gently pull Ion away from the headliner keeping it in the same upright position, base pointed up. Wait at least 3 minutes before reading results.
Two lines signals negative SMOKE FREE
One line signals positive TOBACCO RESIDUE DETECTED
Ion will only detect specific chemicals found in combustible tobacco smoke residue. A positive result reflects the presence of these chemicals at, or above, a certain threshold scientifically proven to be harmful. Results may vary due to varying materials found in vehicle headliners.

For more information, please contact us at
Why choose Ion?
  • Simple and easy to use
  • Instant results, on-site
  • Portal and discreet
  • Low risk of false negatives
  • Affordable and accessible
Alternative Solutions
  • Complicated sample collection process
  • Results available in 7-14 days pending lab analysis
  • Require multiple lab instruments
  • High risk of false negatives
  • Expensive and unpractical
Ion is eco-friendly!

Ion is made from 100% recycled materials.

Cigarette butts are the most abundant form of plastic waste in the world, with about 4.5 trillion individual butts polluting our global environment. Together, we can slow down the spread of tobacco-related pollution.

Don’t just take our word for it
Such a cool product!
"I used Ion to help me shop for my daughter's first car. My family’s health is very important to me! We didn’t have the budget to buy a nicer car from a dealership so we had to find something for sale by the owner online, which always worries me. Ion gave me the peace of mind I needed and helped us find a suitable car for her."
Robert T.
Thank you Knowsmoke!
"My wife and I just had our second child and needed to hire someone to help with the kids and around the house. We interviewed a few people and tested their cars because we knew they would be driving our kids around. Ion helped us make the right choice and keep our family safe."
Moe S.
This is such a good idea.
"I can’t believe how many people still smoke cigarettes after everything we know about them! I’m definitely testing my vehicles for thirdhand smoke before buying them. Can’t trust dealerships..."
Shannon Z.
Super easy to use
"Works just like a pregnancy test or drug test. The mobile app was really helpful too. Awesome product."
Cameron G.
Wow. Love this
"My youngest child has severe asthma and I do everything I can to keep him away from cigarette smoke and allergens. Ion is a must-have for parents!"
Andrea G.
Download the Knowsmoke app to get started
  • The Knowsmoke app helps you interpret results without confusion.
  • With the help of AI, you can scan your results and have them compared to thousands of results in our database, instantly.
  • AI helps significantly reduce user-error and any possible misinterpretations of results.
Questions, meet answers

Thirdhand smoke isn't a dinner table topic just yet. Until then, we've got the answers you're looking for.

Most cars that contain thirdhand smoke will not smell. Automotive companies do their best to mask odors with perfumes and deodorizers. Unfortunately, dealers and rental agencies are currently unable to remove potentially harmful thirdhand smoke residue leaving occupants exposed to health risks. Just because a car doesn’t smell it doesn’t mean thirdhand smoke pollutants are not present. Ion by Knowsmoke is a single-use test kit designed to help you measure thirdhand smoke toxicity when buying, selling, or renting your next vehicle.

Thirdhand smoke is the nicotine and other chemicals from cigarette smoke that remain on surfaces long after someone has smoked. These residues can then be ingested, inhaled, or absorbed through the skin, potentially increasing the risk of certain cancers and other serious diseases.

The research is still emerging, but the scientific community unanimously agrees that thirdhand smoke persists for months, even years, after smoking occurs. Some publications go as far as 5 years.

Exposure mainly occurs via inhalation, ingestion, and dermal (skin) absorption. Children are more vulnerable to ingestion than adults considering the increased contact with their hands and mouth. People are exposed when their skin comes in contact with contaminated surfaces, such as a vehicle’s steering wheel, A/C vents, door handles, or interior upholstery. Once the chemicals found in thirdhand smoke have attached to your skin, they enter your bloodstream and cause harm to your immune system, cardiovascular system, and central nervous system. Contaminated surfaces also release toxins into the air that can enter the body through the lungs when you breathe them in, exposing your respiratory system to a combination of dangerous carcinogens. This can cause respiratory complications, especially for elderly individuals or those with allergies, asthma, or other serious respiratory diseases. Unfortunately, wiping down interior surfaces does not significantly reduce exposure because pollutants are absorbed into the deeper layers of upholstery and carpeting.

It’s very simple! Ion uses similar technology to any at-home test. A small amount of fluid is injected into a vehicle’s headliner where it may collect any tobacco-specific particles. This fluid is then recollected using negative pressure. Now that you’ve collected a sample, it’s time to run a quick diagnostic. The fluid is introduced to a lateral flow immunoassay that will provide a binary result. One line represents a positive result as two lines represents a negative, smoke free result.

Until Ion, there has never been an objective method for determining the presence of thirdhand smoke in any shared-indoor environment. The only alternative is a “smell test”, which is unreliable and easily swindled. Ion empowers users to gauge the possibility of exposure to unwanted, dangerous chemicals found in the remnants of cigarette smoke in just a few minutes. Positive test results are designed around clinically proven concentration levels that pose legitimate health concerns to occupants. If Ion produces a positive result, spending any significant amount of time in the tested vehicle can have a negative impact on your health.

For now, Ion only detects the remnants of combustible tobacco smoke from cigarettes and cigars. Our team is working hard to better understand the health risks associated with thirdhand e-cigarette and cannabis smoke so we can produce similar products that can detect it.

Yes, but different sources will argue over how much. Regardless of where you look, a positive smoke history significantly affects a car’s value. In many cases, evidence of smoking in a vehicle for sale can be a deal-breaker. Some publications suggest that smoke history can affect the list price of a vehicle by $350 to $750, while others have said over $2,000. As a percentage of the asset value, experts suggest that depreciation ranges from 7-12%.

Great question! Hundreds of vehicles are tested with Ion everyday and uploaded to our database. We are building a website function that will allow you to search any vehicle identification number (VIN) to see if it has been tested for thirdhand smoke, its results, and when it was tested. We suggest testing any vehicle that has not been tested for at least 90 days. Vehicle history is an important factor when determining the value of a vehicle. Just like accident history, ownership history, and service history, we believe smoke history should be on the table for discussion. That is why we generate a digital, VIN-specific Smoke History Report for every vehicle tested with Ion for another layer of transparency.