Safety Assured
AS&E's Z Portal® system uses innovative Z Backscatter™ X-ray technology, which ensures that the system's low radiation dose is safe for operators, drivers, and the environment. In fact, one scan is equivalent to flying 1 minute at altitude on an airplane. The Z Portal system meets ANSI N43.17 Radiation Safety for Personnel Security Screening Systems Using X-Ray, which is the standard that the Center for Devices and Radiological Health (CDRH) references for systems such as Z Portal.
Read what the experts are saying about safety:
Health Physics Society
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AS&E’s customers use the Z Portal system within their security and enforcement protocols and under the same national and local laws that govern their overall missions, including rules that govern their ability to search.
Privacy Assured
The Z Portal produces a black-and-white image of the vehicle, in which organic or non-metallic objects (such as drugs, plastics, and explosives) are highlighted. The system creates a silhouette — with no facial or body detail — of a person inside the vehicle. The Z Portal scan only alerts the operator to the presence of a person as only a silhouette and the system cannot be used to identify the individual, or the race, sex or age of the person.
Z Portal creates a silhouette - with no facial or body detail - of a person inside the vehicle that cannot be used to identify the individual, or the race, sex or age of the person.
Safe for All
Z Portal's low radiation dosage is safe for operators, drivers, and the environment and falls well within standards set by The National Council on Radiation Protection (NCRP) and the Nuclear Regulatory Commission (NRC). The dose from the Z Portal system is less than 5 microRem per scan (0.05 microSievert per scan).
To put this into perspective, 5 microRem is equivalent to:
- The radiation a person receives from flying in an airplane for about one minute at 30,000 feet (due to the increased exposure from cosmic rays).
- 1/2 of 1% percent of the radiation dose received by the average person on any day of the year.
- 2000 scans = less than 1 medical chest X-ray
- 1 scan = less than 1/2000th of a medical chest X-ray
It is important to keep in mind that all of us are exposed to ionizing radiation — from sources such as the sun's rays — every single day of our lives. For further reference, the table below shows some comparisons of X-ray dose levels:
| Dose from... | Dose in microRem | Relative to Z Portal Scan |
| One Z Portal Scan | 5 | 1 X |
| Additional background radiation from one day in Denver | 70 | 14 X |
| One hour on an airplane | 300 | 60 X |
| Background radiation per day | 1000 | 200 X |
| Trans-continental flight (round trip) | 4000 | 800 X |
| Chest X-Ray | 5000 - 10,000 | 1000 - 2000 X |
| Average radiation dose per year | 360,000 | 72,000 X |
| CAT scan (Head and Body) | 1,000,000 | 200,000 X |
Frequently Asked Questions about Z Portal Safety and Privacy
I have seen other backscatter images from the airports. Does the Z Portal produce the same images?
No. The images you are referring to were produced by a type of system referred to as a Advanced Imaging Techology (AIT). These systems are designed to find objects concealed underneath people's clothing. Moreover, the current versions of AIT systems no longer produce the detailed image you are referring to.
The Z Portal system does not produce images like this. The Z Portal is designed to image and inspect the vehicle. The Z Portal scan alerts the operator to the presence of a person inside the vehicle as only a silhouette - with no facial or body detail. The system cannot be used to identify an individual, or the race, sex or age of the person.
Do the system operators receive a radiation dose?
The radiation dose to system operators from the Z Portal will be no more than 50 microRem in an hour since operators will stand outside of a delineated zone called the "controlled area". The Nuclear Regulatory Commision (NRC) sets the maximum radiation exposure for members of the general public at of 100,000 microRem (0.1 rem) in a year. A Z Portal operator could stand at the boundary of the controlled zone 40 hours a week, 50 weeks a year - and still be within this safe limit.
Does the driver need to exit the vehicle for a scan?
No, the Z Portal is a safe drive-through system. Drivers and passengers stay in their vehicles while driving through the system.
Is Z Portal safe for everyday use?
Yes, the Z Portal system is safe for everyday use — According to the published ANSI Standard N43.17-2009 "Radiation Safety for Personnel Security Screening Systems Using X-Ray and Gamma Radiation", at the Z Portal dose level of 5 microRem (0.05 microSieverts) per scan an individual could be scanned 5,000 time per year—416 scans monthly; 96 scans weekly; 13 scans daily—before reaching the annual limit suggested for security screening by the U.S. National Council on Radiation Protection and Measurements of 25,000 microRem per year (based on 100,000 microRem per year from all man-made non-medical sources – with no more than 25% (25,000 microRem) from any one source).
How many times can a person be scanned by Z Portal?
The Z Portal, with an effective dose of 5 microRem (0.05 microSieverts) per scan, meets ANSI Standard N43.17-2009 "Radiation Safety for Personnel Security Screening Systems Using X-Ray and Gamma Radiation" at 5000 screenings per year (416 scans monthly; 96 scans weekly; 13 scans daily).
What is the American National Standards Institute (ANSI) and what is the applicable standard for Z Portal?
The American National Standards Institute (ANSI) is a private organization that develops consensus standards by chartering subcommittees of experts. These standards are published and copyrighted by ANSI. The Center for Devices and Radiological Health (CDRH) can use the standards written by an ANSI committee to classify a system that does not fall into one of the main categories specified in the mandatory standards. The ANSI standard N43.17-2009 "Radiation Safety for Personnel Security Screening Systems Using X-ray and Gamma Radiation" is one such standard and it was written by a subcommittee chaired by the Health Physics Society. The standard covers dose to subject, interlocks, operational procedures, information to provide to subjects, training for operators as well as other information. Z Portal meets the manufacturer's requirements of ANSI/HPS standard N43.17-2009.
What is the Center for Devices and Radiological Health (CDRH) and what is the applicable standard for Z Portal?
The Center for Devices and Radiological Health (CDRH) is the regulating body of the Food and Drug Administration (FDA) charged with oversight of electronic product safety, including radiation producing equipment. Z Portal meets manufacturer's requirements of the American National Standards Institute (ANSI) standard N43.17-2009, which is the standard that CDRH references for systems such as Z Portal.
What happens if a pedestrian walks in front of the backscatter van while a scan is in progress? Or if a driver stops in the scan or drives too slowly?
The Z Portal is equipped with numerous safety mechanisms. It is fully interlocked for X-ray safety; any malfunction that could cause an unexpected increase in exposure to the scanned vehicle is interlocked to prevent X-ray generation. The speed of vehicles driving through the Z Portal system is electronically monitored and X-rays are immediately shut off if the speed falls below the required threshold. The Z Portal system also incorporates redundant safety controls, such as emergency shutoff pushbuttons, at several locations on the systems.
Additionally, the personnel assigned to operate the Z Portal systems are specifically trained for safe X-ray system operations.
