Objective of the RADTriage 2.0

The RADTriage 2.0, a stockpileable personal radiation detector, provides wearers, medical personnel and law enforcement personnel timely personal radiation exposure information in an event of a terrorist radiological incident or industrial accident. RADTriage 2.0, with the amber laminated filter, provides significantly longer life in direct sunlight. RADTriage 2.0, part of the SIRAD (Self-Indicating Radiation Alert Dosimeter) family of SMART dosimeters, is uniquely designed to prevent erroneous readings. It has a sensor (a rectangular strip between the color bars) with 0, 2, 5, 10 & 25 rads bars on its top and 50, 100, 200, 400 & 1,000 rads bars on its bottom for triaging information in emergencies. If, during or after the incident, the color of sensor has not changed, the wearer has not received radiation exposure large enough to cause acute medical effects and therefore has peace of mind. If the sensor changes color, radiation exposure is indicated. In this case, further exposure should be avoided. If the Sensor has developed a darker color, e.g., above 25 or 50 rads, the user should seek a medical evaluation. A person exposed to a dose higher than 50 rads should immediately contact the emergency room of the nearest hospital.

Introduction

The RADTriage 2.0 (USP# 7,227,158 and others) is always active and ready to use. It is a smart dosimeter and has the capability of monitoring shelf life, false positives/negatives and tampering. When exposed to radiation, e.g., from a "dirty bomb", the sensor of the RADTriage 2.0 changes color instantly. The color changes are permanent, cumulative and proportional to dose, thereby providing the wearer and medical personnel instantaneous, easy to read information on radiation exposure of the wearer to assess the health risks and guide medical treatment.

Types of Radiation

The RADTriage 2.0 sensor responds to gamma/X-ray (energy higher than 30 KeV) and high energy (e.g., above 1 MeV) electrons/beta particles. Color development of the Sensor is essentially independent of dose rate. However, protective films attenuate low energy (below 200 KeV) X-ray. RADTriage 2.0 will not be affected by normal exposures to diagnostic X-rays (e.g., chest or dental) or security/airport X-ray/CAT scan machines, except that multiple exposures (more than five) to such will result in sufficient enough exposure to produce a detectable color change in the sensor.

How to Read Dose with RADTriage 2.0

Estimate the exposure dose by comparing the color of the sensor with the Sensor Reference Bars. Find a bar which closely matches the color of the sensor and read the dose in rads/mSv printed adjacent to those bars. If the Sensor develops a color in-between any two adjacent bars, this indicates an in-between dose. For a nearly tissue equivalent dosimeter, such as RADTriage 2.0, 1 rad = 1 rem = 10 mSv. It can be viewed in any light. However, we recommend reading the dose under fluorescent lights for better accuracy. Color matching under other lights may not be as accurate. Dose can be estimated with an uncertainty of about 20% with a color-matching reference chart. Where additional accuracy is needed, a spectrophotometer or an optical densitometer can be used to determine the dose to within 10%.

Effects of Heat and UV Light

The sensor of the RADTriage 2.0 will develop colors faster if exposed to UV/sunlight for a prolonged period. Keep the RADTriage 2.0 at or below normal body temperature. Repeated, e.g., hundreds, of readings where the sensor gets exposed for less than a minute per reading (even under direct sunlight) will cause little or no color development in the sensor.

False Positive and Tamper Indicators 

If used as per instructions, it is unlikely that the RADTriage 2.0 will provide false positives or false negatives. Your RADTriage 2.0 is a SMART personal dosimeter, equipped with a simple-to-use revolutionary indicator for monitoring the deliberate or inadvertent exposure to high temperatures or ultraviolet light. We call it the FIT Indicator (False-positive,Inactivation and Tamper) and it is located on the right hand end of the sensor. The FIT Indicator simultaneously monitors false positives & negatives, overexposure to heat & UV/ sunlight, shelf-life, inactivation and/or altered sensitivity.

Inactivation & False Negative Indicator: If the central dot of the FIT Indicator is dark blue, the sensor is active, it is monitoring radiation and the calibration is valid. However, if it has changed to red, your RADTriage 2.0 has been heated near or above 175^oF/80^oC which has made the sensor inactive to radiation or of altered sensitivity to radiation. DO NOT USE the dosimeter if the central dot of the FIT Indicator is red. Turn the dosimeter in to the issuing organization with a description of the circumstances. The heat treatment can be used by medical authorities to fix the sensor for permanently documenting the radiation exposure as a part of a medical record. Medical personnel requiring this capability should contact the distributor, Justacip, Inc.

False Positive Indicator: The shelf life (expiration date) of the dosimeter is based on storage of the RADTriage 2.0 at room temperature (77^oF/25^oC) or below and continuous protection from ultraviolet/sunlight exposures. Shelf life will be reduced if it is stored at higher temperatures and/or exposed to UV/sunlight for a prolonged period (e.g., more than a few hours of direct sunlight). The area surrounding the central dot should be lighter in color when issued/purchased. If it has developed a color matching or darker than the Color Reference Bar on its right, the shelf-life of the RADTriage 2.0 has expired; it was overexposed to UV light, and/or exposed to higher temperatures for a prolonged period.  The sensitivity of the FIT Indicator to X-rays is hundreds of times lower than that of the sensor.

Shelf-Life

The sensor of the RADTriage 2.0 will develop color equivalent to about 1 rad in about one year if stored at 77^oF/25^oC. The shelf-life/guaranty of the RADTriage 2.0 expires one year from the issue date and definitely when the color of the area surrounding the central dot of the FIT Indicator matches or is darker than the Color Reference Bar on the right hand side. However, the shelf-life of the RADTriage 2.0 can be extended to about five years if kept in a freezer until ready to use.

UV/Tamper Detector

A small portion of the sensor is covered with the FIT Indicator. The substrate of the FIT Indicator is 100% opaque to visible and UV light but transparent to X-rays and gamma-rays. If the color development of the sensor is due to exposure to high energy ionizing radiation, the whole sensor will be uniformly colored. If the color development of the sensor is due to exposure to UV light, the color of the sensor under the FIT Indicator will be significantly lighter. If you suspect the color development of the sensor is due to exposure to high energy ionizing radiation, return the RADTriage 2.0 to Justacip, Inc. For a fee, we will remove the sensor for determination of genuine exposure or false positive.

Reporting Exposure

If the sensor of the RADTriage 2.0 develops darker color and the color development is not due to prolonged exposure to high temperatures, UV/sunlight, and/or expiration of shelf life, estimate the dose and immediately report it to the department/agency/organization issuing the dosimeter. Seek advice and medical help immediately from your agency/company medical office, your personal health care provider or county public health office, especially if the dose is higher than 25 rads. For a dose higher than 100 rads, report to the nearest Emergency Room.

Department of Homeland Security Evaluation Against Test Criteria 

• Is the SIRAD [RADTriage 2.0] format usable by emergency responders without significant damage, loss, or interference with operations?
Yes. In the field deployment, 8 percent were lost, 10 percent were found to have slight damage (which did not affect their performance), and less than 1 percent were damaged severely enough to compromise performance. Feedback from participants was positive.

• In routine field deployment, does the SIRAD [RADTriage 2.0] have a false positive probability of less than 1
percent?
Yes. The positive readings observed in the field deployment were for 4 dosimeters having obvious, severe damage to the protective cover, which identified them as suspect. These did not cause concern among the users: they were light blue and were interpreted by the POC as less than 5 rad. They represent less than 1 percent of those deployed.

• Are the SIRAD [RADTriage 2.0] radiation response and calibration acceptable in the context of existing standards for other types of emergency dosimeters?
Yes. The SIRAD [RADTriage 2.0] was tested against ANSI N13.11, though such a standard would likely be considered too high for a device that is not intended to be used for a legal dose of record. The SIRAD [RADTriage 2.0] performed reasonably well, passing one of the three categories tested, even when doses beyond its upper scale range were included. The laboratory tests revealed a difference in response to photons of different energies (73 and 662 keV), which is common in many dosimeters including TLDs, where it maybe corrected with filters or calibration adjustments). Since the SIRAD [RADTriage 2.0] was shown to over-respond to higher energy photons, it would tend to err on the side of caution in this case.

• Can the color scale on the SIRAD [RADTriage 2.0] card be accurately interpreted visually?
Not in all cases, but this should not be significant for the intended tactical applications. Color interpretation is subjective and corresponding numerical dose estimates vary between individuals, so the SIRAD [RADTriage 2.0] should not be used for routine occupational dosimetry of record. However, doses significantly (factor of 3) above a reference decision level of 25 rad apparently can be easily identified for tactical decisions, despite the differences in assigning a corresponding numerical value. Future studies will investigate this topic in more depth.

• Are the manufacturer’s specifications accurate?
Yes, in most cases. The specifications for functional temperature and light conditions, and photon, and beta response are accurate. However, the SIRAD [RADTriage 2.0] did not demonstrate neutron sensitivity. Since neutrons are difficult to measure, this is common among other types of photon dosimeters and it is not crucial for the intended application since neutron sources are expected to have a significant gamma component.

• Does the card function under potential end-user environmental stresses?
Yes. Dosimeters returned from the field, left in a hot automobile, and put through the laundry continue to function.

• Is the SIRAD [RADTriage 2.0] card appropriate for use by first responders for preparedness for potential radiological terrorist events?
Yes. It provides a color change that gives a field readable indication of a significant radiation exposure that could be valuable for tactical operations. Its low-cost and convenient format do not interfere with operations and would be useful for pre-distribution to emergency responders who would not otherwise use dosimetry but could be involved in the early response to a terrorist event.

Warranty

Reasonable efforts have been made to make this product free from defects. It is expected to perform as specified if used as recommended and instructions are followed. In the event that the product does not perform as specified, JP Laboratories, the manufacturer, will replace the product. JP Laboratories specifically disclaims all other warranties and liabilities expressed or implied. All warranties are null and void if any of the following occur: (1) the central dot of the FIT Indicator is purple or red and/or the area surrounding the dot is matching or darker than that of its Color Reference Bar and (2) the RADTriage 2.0 is tampered with in any way.
The shelf-life/warranty expires one year after the issue/sell date. 
Note: A normal residential laundry cycle of washing and drying (below 175°F/80°C) has a negligible effect on the RADTriage 2.0. However, repeated laundry cycles or exposure to temperatures higher than 175°F/80°C will damage the sensor and hence must be avoided. Replace the RADTriage 2.0 if it is subjected to boiling water or more than one laundry cycle.