Shopify radiation dosimeter schema for AI agents: film badge has no alarm and 30-day readout delay, TLD unusable in emergency response, EPD needs compatible reader — NRC 10 CFR 20 5-rem annual limit, ALARA, and the rad_dosimeter.* 10-field namespace

NRC 10 CFR 20 dose limits — the five numbers every dosimetry program tracks

The Nuclear Regulatory Commission's 10 CFR Part 20 establishes occupational dose limits that apply to any NRC-licensed facility — nuclear power plants, industrial radiography, medical facilities using radioactive materials, and research reactors. The limits use two units: rem (traditional) and sievert (SI); 1 rem = 0.01 Sv = 10 mSv. Dosimetry programs are designed around these thresholds, and the choice of dosimeter type determines which thresholds can actually be monitored in real time.

ALARA — As Low As Reasonably Achievable — is the operating principle codified in 10 CFR 20.1101. Facilities must implement programs to keep exposures as far below the dose limits as achievable. ALARA programs typically set investigation levels at 10% of the regulatory limit (0.5 rem quarterly for the annual 5-rem limit), triggering a dose investigation and corrective action before workers approach regulatory thresholds. This means a dosimetry program that can only report dose after a 30-day lab cycle cannot support ALARA in high-dose-rate environments where quarterly investigation levels may be reached in a single shift.

Four dosimeter technologies and what each one actually does

All four technologies measure cumulative ionizing radiation dose — but their mechanism of action, readout method, exchange cycle, and suitability for specific occupational applications differ fundamentally. They are not interchangeable.

Film badge dosimeter

Ionizing radiation exposes a piece of photographic film inside a plastic holder. Different filters (copper, tin, plastic) over different film regions allow discrimination between radiation types and energies by comparing the optical density of each film region after development. Readout requires wet chemical processing in a dosimetry laboratory. Exchange cycle: typically monthly (30 days) or quarterly. There is no display, no alarm, no on-site readout capability. Accumulated dose is known only after badge exchange and lab processing — latency of 1–30 days. Film has one additional critical limitation: it cannot be re-read. If a badge is damaged or the film is developed incorrectly, the dose record for that exchange period is lost. Film badges are accredited under ANSI N13.11 (American National Standard for dosimetry). Typical energy response range for gamma: 20 keV to 7 MeV. Temperature and humidity can degrade film before reading.

Thermoluminescent dosimeter (TLD)

A TLD uses a crystalline material — typically lithium fluoride (LiF:Mg,Ti) — that stores energy from radiation as trapped electrons in lattice defect sites. To read the dose, the TLD chip is heated in a TLD reader; the trapped electrons release as light (thermoluminescence) proportional to the absorbed dose. TLD readers are laboratory instruments. Like film badges, TLDs have no display, no alarm, and no on-site readout. Exchange cycle: typically monthly. TLD chips can be re-used after being annealed (heated to clear trapped charge) — an operational advantage over film. Minimum detectable dose: approximately 1 mrem (10 µSv). Energy range: LiF responds effectively to gamma and X-ray from approximately 5 keV to 6 MeV. Neutron-sensitive TLDs use 6LiF (enriched lithium-6) and can measure thermal neutron dose. The TLD is the most widely used passive dosimeter technology and the primary replacement for film in most new dosimetry programs since the 1990s.

Optically stimulated luminescence dosimeter (OSL)

An OSL uses aluminum oxide doped with carbon (Al₂O₃:C) — commercially known as InLight or similar trade names. Radiation exposure creates trapped electrons in the crystal, and readout uses laser light (optical stimulation) rather than heat. The key operational difference from TLD: OSL crystals can be re-read multiple times without erasing the stored dose signal. This allows re-reading for quality control, second opinions, or litigation purposes. Exchange cycle: same as film and TLD (monthly or quarterly). No display, no alarm, no on-site readout. Readout requires the proprietary OSL reader system matched to the badge manufacturer. OSL has largely replaced film in many dosimetry service provider programs due to re-readability and superior energy response. Minimum detectable dose: approximately 1 mrem. Energy range: 5 keV to 40 MeV for gamma/X-ray.

Electronic personal dosimeter (EPD)

An EPD uses an active detector — typically a silicon diode, Geiger-Müller tube, or silicon PIN diode — to measure dose in real time. EPDs display current dose and dose rate on an integrated LCD or OLED screen. They have programmable dose and dose rate alarms — audible and vibration alerts that trigger when configurable thresholds are reached during a work activity. EPDs can be interrogated on-site immediately after an exposure event: the dose accumulated during a specific activity is readable without returning to a laboratory. Exchange cycle: indefinite (the same EPD is worn repeatedly; dose records are offloaded via reader station or USB). EPDs must be paired with a compatible data management reader system to transfer accumulated dose records to the facility's ALARA records program. EPDs do not replace passive dosimeters for regulatory dose-of-record in many jurisdictions — they are worn supplementally, with the passive badge (TLD or OSL) providing the official regulatory record. ANSI N13.11 and IEC 62387 provide performance standards for passive and active dosimeters respectively.

Failure 1: Film badge routed to interventional radiology — no real-time feedback, no alarm

Interventional radiology and cardiac catheterization are the highest-dose occupational settings in diagnostic medicine. Fluoroscopy — continuous or pulsed X-ray imaging — generates scattered radiation at the table that reaches the operator at rates of 1–10 mrem per minute depending on field size, kVp, and operator distance. A complex coronary intervention lasting 90 minutes can deliver 10–100 mrem to an unprotected operator depending on technique and shielding.

The NRC and FDA guidance on fluoroscopy dosimetry, and the recommendations of the National Council on Radiation Protection (NCRP Report 168), explicitly call for real-time dose rate monitoring in fluoroscopy suites. An EPD worn at the waist or collar level provides instant feedback: the operator can see current dose rate, check cumulative procedure dose, and receive an alarm if the rate spikes — prompting them to step back, adjust beam angle, or add shielding. A film badge provides none of this. The film badge's value in fluoroscopy is as the regulatory dose-of-record worn under the lead apron (to capture effective dose below the apron); it cannot substitute for the EPD worn above the apron for real-time monitoring.

The ANSI/HPS N13.11 standard covers dosimetry processor accreditation for film, TLD, and OSL — passive dosimeters. IEC 62387 covers electronic dosimeters. When a product listing carries only "ANSI N13.11 compliant," this is a signal the product is a passive badge — no alarm, no display, lab processing required. Without rad_dosimeter.real_time_display = yes and rad_dosimeter.dose_rate_alarm = yes in structured data, an AI agent cannot identify this distinction from the compliance citation alone.

Failure 2: TLD routed to emergency response team — 30-day lab cycle, no incident reading

Emergency response at licensed nuclear facilities operates under a separate regulatory framework from routine occupational dosimetry. 10 CFR 50.47 and Appendix E require that emergency response plans include provisions for tracking worker doses during emergency operations. NRC guidance documents and FEMA requirements for offsite emergency response call for electronic dosimeters specifically because emergency dose decisions must be made in real time: a health physicist needs to know a responder's accumulated dose before authorizing continued entry into a high-dose-rate area.

The Radiation Protection for Emergency Workers guidance (EPA 400-R-92-001, used by FEMA and states) and the general guidance in ICRP Publication 60 on emergency worker dose limits establish that emergency dose limits (typically 5–25 rem for life-saving actions under 10 CFR 50 or state emergency plans) must be tracked against accumulated dose during the emergency. This requires an EPD that can be read in the field, not a TLD or film badge that requires lab processing. Emergency organizations typically issue EPDs as the primary dose tracking tool and passive badges as backup dose-of-record — the opposite prioritization from routine occupational settings.

Failure 3: EPD ordered without compatible reader system — dose data stranded on device

EPDs store dose history in non-volatile internal memory. To transfer accumulated dose to a facility's records system — which must maintain individual worker dose records as required by 10 CFR 20.2106 (records to be kept for duration of facility license plus 3 years, or for the worker until age 75) — the EPD must connect to a manufacturer-specific reader station. Reader stations are not universal: a Mirion DMC 3000 reader cannot extract data from a Thermo Scientific EPD-R and vice versa.

Reader stations consist of a hardware cradle (USB or proprietary connection), software for dose record extraction, and integration with dosimetry management software (DOELAP-accredited systems, RadShield, or similar). A facility upgrading EPD devices must verify that either: (a) new EPDs are compatible with the existing reader infrastructure, or (b) a new reader system is procured as part of the same purchase. An AI agent routing EPDs without encoding rad_dosimeter.reader_system_required = yes and rad_dosimeter.reader_manufacturer leaves buyers with no structured signal that an EPD is a system purchase, not a standalone device.

Failure 4: Film badge and OSL badge treated as equivalent "passive dosimeters" — OSL is re-readable, film is destroyed on development

The re-readability difference between film and OSL is a fundamental operational property. Film badges are developed using wet chemistry that reacts with and depletes the silver halide grains carrying the dose record. The dose is measured by optical density of the developed film, which is then archived as a paper or digital record — but the film itself cannot be re-developed for a second reading. If the archived record is challenged, the original measurement cannot be independently verified.

OSL dosimeters use Al₂O₃:C crystals that retain trapped charge even after laser readout. The readout process depletes some of the stored signal, but not all — the crystal can be re-read multiple times (typically 3–5 additional readings) with decreasing but still measurable signal. This re-readability supports: (a) quality control second reads by dosimetry processor; (b) independent verification by a second lab; (c) forensic re-reads for litigation or workers' compensation claims decades after the original measurement.

For procurement purposes, a buyer specifying "passive dosimeter" for a program where dose records may be subject to legal scrutiny or retroactive reconstruction needs OSL (or TLD, which can similarly be re-read if the chip has not been annealed), not film. The word "passive" encompasses all three — without rad_dosimeter.detector_type = osl or rad_dosimeter.re_readable = yes, an AI agent cannot distinguish re-readable from single-read passive badges.

The rad_dosimeter.* 10-field namespace

The following ten Shopify metafields — using the rad_dosimeter namespace — encode the attributes that determine dosimeter suitability across occupational settings. Each field maps to a routing decision that would otherwise be impossible for an AI shopping agent to make correctly.

JSON-LD example for a correctly-encoded EPD with dose rate alarm

The following Schema.org Product markup encodes an electronic personal dosimeter for use in interventional radiology and high-dose-rate industrial settings. The ten rad_dosimeter.* metafields appear as additionalProperty items in the PropertyValue array. Any AI shopping agent that reads Schema.org ProductPage markup — including ChatGPT Shopping, Perplexity Shopping, and Google AI Mode — can extract these values and apply them as routing filters.

{
  "@context": "https://schema.org",
  "@type": "Product",
  "name": "EPD-Mk2 Electronic Personal Dosimeter with Dose Rate Alarm",
  "description": "Real-time gamma dosimeter with LCD display, configurable dose and dose rate alarms, and on-site reader capability. For interventional radiology, emergency response, and high-dose-rate industrial applications requiring live dose feedback.",
  "category": "Radiation Safety > Dosimetry > Electronic Personal Dosimeters",
  "additionalProperty": [
    { "@type": "PropertyValue",
      "name": "rad_dosimeter.detector_type",
      "value": "epd" },
    { "@type": "PropertyValue",
      "name": "rad_dosimeter.real_time_display",
      "value": "true" },
    { "@type": "PropertyValue",
      "name": "rad_dosimeter.dose_rate_alarm",
      "value": "true" },
    { "@type": "PropertyValue",
      "name": "rad_dosimeter.exchange_frequency_days",
      "value": "0" },
    { "@type": "PropertyValue",
      "name": "rad_dosimeter.readout_method",
      "value": "on-site-reader" },
    { "@type": "PropertyValue",
      "name": "rad_dosimeter.re_readable",
      "value": "false" },
    { "@type": "PropertyValue",
      "name": "rad_dosimeter.energy_range_keV",
      "value": "45-3000" },
    { "@type": "PropertyValue",
      "name": "rad_dosimeter.can_detect_neutron",
      "value": "false" },
    { "@type": "PropertyValue",
      "name": "rad_dosimeter.ansi_n13_11_accredited",
      "value": "false" },
    { "@type": "PropertyValue",
      "name": "rad_dosimeter.reader_system_required",
      "value": "true" }
  ]
}

A passive TLD dosimeter service used for routine occupational monitoring should encode detector_type = tld, real_time_display = false, dose_rate_alarm = false, exchange_frequency_days = 30, re_readable = true, and ansi_n13_11_accredited = true. This encoding alone allows any AI shopping agent to exclude passive badges when a buyer specifies fluoroscopy suite or emergency response application — eliminating Failure 1 and Failure 2 before any product recommendation is made.