Body Scanners: What Airports Use This Technology?

Airport body scanners are used to detect threats such as weapons, explosives, or other prohibited items. They use millimeter-wave technology, which is safe for pregnant people and those with pacemakers. The scanners do not produce naked images of passengers, but rather a generic body outline with a box indicating the area of concern. While you can refuse to go through a body scanner, you will be subjected to alternative screening methods such as a pat-down.

What do body scanners see?

Body scanners use various technologies to produce images that can be used to detect hidden items. The two most common types of body scanners are backscatter X-ray scanners and millimeter wave scanners. Backscatter X-ray scanners use low-dose X-rays to produce images of the body. The X-rays are reflected off the skin and clothing and picked up by detectors. These scanners can detect items hidden under clothing, such as weapons or explosives, but they cannot see what is inside the body. Millimeter wave scanners work in a similar way, emitting energy that is reflected back to detectors. These scanners can penetrate clothing but bounce off the skin.

Transmission X-ray scanners are another type of body scanner, emitting low-dose X-rays that penetrate the body and produce an image on the other side. These scanners are more commonly used in prisons and can detect items hidden under clothing or inside body cavities.

The use of body scanners has been controversial, with critics arguing that they violate privacy and are essentially "virtual strip searches". In response to these concerns, some airports have implemented privacy measures, such as obscuring the person's face or having the operator view the scan from a separate room. Additionally, the current body scanners used by the TSA only display a generic outline of a person, with indicators for areas that require further inspection.

Despite the concerns, several radiation safety authorities, including the National Council on Radiation Protection and Measurements, the Health Physics Society, and the American College of Radiology, have stated that they are "not aware of any evidence" that full-body scans are unsafe. However, other organizations, such as the International Atomic Energy Agency and the Nuclear Energy Agency, recommend against using ionizing radiation on certain populations like pregnant women and children.

Are body scanners safe?

The safety of body scanners at airports has been a topic of debate, with concerns about both privacy and potential health risks. The Transportation Security Administration (TSA) in the US has deployed two types of full-body scanners: millimeter-wave scanners and backscatter X-ray scanners. While millimeter-wave scanners emit extremely low-energy waves, similar to those emitted by cell phones, backscatter X-ray scanners utilize very low-dose X-rays, comparable to those used in medical imaging.

The primary health concern regarding body scanners is the use of ionizing radiation, which can cause biological damage and potentially lead to cancer or other abnormalities at moderate to higher doses. However, the doses of ionizing radiation emitted by backscatter X-ray scanners are exceedingly low, and the TSA considers the risk of harm trivial. Experts agree that passengers should not fear the scans for health reasons, as the risks are minimal. Additionally, the TSA has implemented safety measures to prevent the exposure of workers and travelers to high levels of ionizing radiation.

While the benefits of body scanners in enhancing security and detecting non-metal threats are evident, some experts have questioned their efficacy and accuracy. There have also been concerns about the improper saving and dissemination of scanned images, as well as the potential for employees to alter machine settings. Nevertheless, the TSA has taken steps to address these issues, such as making it impossible for scanners deployed in airports to save or export images.

In summary, while body scanners at airports do emit low levels of radiation, the risks to passengers are generally considered negligible. However, individuals with specific underlying medical conditions or those who are pregnant may opt for a pat-down search instead of walking through the scanners. Overall, the benefits of improved security and the detection of potential threats likely outweigh the minimal health risks associated with body scanners.

Can I opt-out of a body scanner?

Yes, you can opt out of a body scanner at the airport. However, this does not excuse you from security screening procedures. If you opt out of a full-body scanner, you will be subjected to a full-body pat-down search instead.

To opt out, inform the TSA agent at the checkpoint that you would like to do so. They will then ask you to step out of the way and wait until an agent of the same sex becomes available to pat you down. You will also be asked to point out your luggage coming through the x-ray machine.

It is important to note that opting out may take longer than simply going through the body scanner, and you may experience a more aggressive pat-down. Additionally, if you are selected for "enhanced screening" (indicated by "SSSS" on your boarding pass), the TSA can still require you to go through the body scanner.

While full-body scanners are the primary method of clearing passengers before boarding their flights, they are not mandatory, and you have the right to opt for an alternative security procedure.

What happens if I set off the body scanner?

If you set off the body scanner at the airport, you will be subjected to a physical body search, also known as a pat-down. This will be performed by a TSA officer of the same gender, who will be wearing clean gloves and will explain the procedure to you. If they need to touch you in private areas, they will use the backs of their hands. You can ask for the pat-down to be conducted in a private room, in which case another TSA agent will be present, and you can bring someone with you.

Body scanners are mainly used to detect if a passenger is attempting to fly with a weapon or explosives. They use either backscatter or millimeter-wave technology to detect solid items on your person. Backscatter X-ray scanners use ionizing radiation to reveal solid items, while millimeter-wave scanners use electromagnetic waves to create 3D images of everything on your body.

Today's millimeter-wave machines do not show nipples or genitalia, and they do not pick up size, weight, or height. Instead, they generate a generic image of a body with a box representing the area that triggered the scanner.

There are many reasons why you might set off a body scanner. If you have a higher body fat content, you are more likely to set off the scanner, as harmless things like lipomas (fatty lumps) or lipodystrophy (abnormal fat distribution) can show up. False alarms are also more likely if you have an afro, braids, or dreadlocks.

Surprisingly, glycerin, which is commonly found in skincare products, has been known to cause false alarms because it can be used to make explosives. If you know you have used a product containing glycerin, thoroughly washing your hands can help you avoid this. Medical devices like pacemakers could also cause a false alarm, so it is important to let the TSA know before you enter the scanner.

What items set off body scanners?

Airport body scanners use millimeter wave imaging, which uses electromagnetic radiation to detect threats. This technology is more effective than metal detectors as it can identify items hidden in clothing.

Body scanners are sensitive and can flag unexpected items as potential threats. For example, a 2016 case study revealed that scanning devices can misinterpret cysts and other skin lesions as foreign objects. Even sweat can set off the machines. Clothing and accessories can sometimes appear on body scanner readings, which is why it's important to remove jackets, scarves, and other bulky layers when passing through security. It's also important to limit body jewelry and be mindful of hidden metal in clothing (such as bra underwires).

Glycerin, traditionally used in lotion, soap, baby wipes, and more, has been known to cause false alarms. The scanners can mistake glycerin for an explosive substance as the compound can be used to make dynamite and bombs.

Medical devices like pacemakers could also cause a false alarm, so it's important to let TSA know before entering a full-body scanner.

If you don't want to go through a full-body scanner, you can opt for a pat-down screening instead. A TSA officer of the same gender will conduct the pat-down and will wear clean gloves, explaining the procedure to you. If they need to touch you in private areas, they will use the backs of their hands. You can also request to have the pat-down conducted in a private room, and you can bring someone with you.

Frequently asked questions