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    PrintWhat’s new | Fast facts | FDA’s role | Medical countermeasures | Guidance for industry | Statements and updates | Additional resources | Contact FDA

FDA and other agencies work hard every day to help prepare the nation for potential threats.

Everyone can be involved in disaster readiness by learning more about different types of emergencies, and creating an emergency supply kit and family emergency plan.

What's new

**September 29, 2023:** FDA approved a new indication for Stimufend (pegfilgrastim-fpgk) to increase survival of adult and pediatric patients acutely exposed to myelosuppressive doses of radiation (Hematopoietic Syndrome of Acute Radiation Syndrome, or H-ARS) as could occur after a radiological or nuclear event. Stimufend is the sixth FDA-approved medical countermeasure and second biosimilar that is indicated to increase survival in patients exposed to myelosuppressive doses of radiation. For more information, see the product label.
	**April 19, 2023:**FDA announced availability of a draft guidance for industry, Acute Radiation Syndrome: Developing Drugs for Prevention and Treatment. The purpose of this draft guidance is to provide information and recommendations to assist sponsors and other interested parties in the development of drugs to prevent or treat acute radiation syndrome (ARS) caused by exposure to ionizing radiation from accidental or deliberate events. Generally, drugs developed for such indications will require approval under the regulations commonly referred to as the Animal Rule. Submit commentsby **July 19, 2023**.
	**March 3, 2023:** FDA approved (PDF, 296 KB) a new single-dose prefilled auto-injector presentation of Udenyca (pegfilgrastim-cbqv) to increase survival of adult and pediatric patients acutely exposed to myelosuppressive doses of radiation (Hematopoietic Syndrome of Acute Radiation Syndrome, or H-ARS) as could occur after a radiological or nuclear event. For more information, see the product label (PDF, 1.3 MB).
	**November 28, 2022:**FDA approved a new indication (PDF, 244 KB) for Udenyca (pegfilgrastim-cbqv) to increase survival of adult and pediatric patients acutely exposed to myelosuppressive doses of radiation (Hematopoietic Syndrome of Acute Radiation Syndrome, or H-ARS) as could occur after a radiological or nuclear event. Udenyca is the fifth FDA-approved medical countermeasure and first biosimilar that is indicated to increase survival in patients exposed to myelosuppressive doses of radiation. For more information, see the product label (PDF, 460 KB).Fast facts about radiation emergencies

*From the Centers for Disease Control and Prevention (CDC)*

During a radiation emergency, the most important steps you can take are to get inside or take shelter, stay inside to reduce your exposure to radiation, and stay tuned for further instructions on what to do.
	Where to go in a radiation emergency (video, 1:35)
		Frequently asked questions about radiation emergencies
	Potassium iodide (KI) specifically blocks the uptake of radioactive iodine into the thyroid gland. Only take KI on the advice of a medical doctor, public health, or emergency management officials. Taking too much KI or taking KI when it is not recommended can have serious health risks.**Learn more about radiation emergencies**

FDA's role

FDA plays a critical role in protecting the United States from chemical, biological, radiological, nuclear, and emerging infectious disease threats.

FDA’s roles in radiological and nuclear emergency preparedness and response include:

**Facilitating the development and availability of medical countermeasures (MCMs)**that can be used to diagnose, prevent, protect from, or treat conditions including those that result from radiation exposure. *Also see Medical countermeasures below, and What are medical countermeasures?*
	**Ensuring the safety and security of FDA-regulated products**that may be impacted, or used to respond to public health emergencies. This includes ensuring food safety and medical product safety when manufacturing facilities are in an area impacted by a disaster.
	**Working with medical product sponsors**to clarify regulatory and data requirements necessary to rapidly advance development of products essential to supporting response efforts. *Also see Guidance for industry below*
	**Protecting consumers against fraudulent products** - Unfortunately, during emergency situations, fraudulent products claiming to prevent, treat or cure conditions associated with the emergency almost always appear for sale. The FDA monitors for fraudulent products and false product claims related to radiation and nuclear protection and takes appropriate action to protect consumers.
	**Conducting research** to develop the tools, standards, and approaches to assess MCM safety, efficacy, quality, and performance and to help translate new technologies into innovative, safe, and effective MCMs. For example, FDA research includes an ongoing project to develop models of radiation damage in lung, gut, and bone marrow organs-on-chips and use these models to test candidate MCMs to treat such damage.
	**Leading the Advisory Team for the Environment, Food and Health**, a federal interagency group of subject matter experts in radiological health and related matters. *Also see Advisory Team below*Medical countermeasures (MCMs)

Overview | About ARS | MCMs for H-ARS | Internal contamination

Overview

Exposure to radiation can affect the body in several ways. The adverse health effects from exposure to radiation range from mild, such as skin reddening, to serious, such as Acute Radiation Syndrome (ARS), cancer, and death. The adverse health effects of radiation exposure depend on the amount and type of radiation absorbed by the body. The duration of exposure (short vs. continuous) causes different adverse effects.

Exposure to radiation during a radiological or nuclear emergency can result from exposure to an external radiation source without any direct contact with radioactive materials, from direct contamination with radioactive materials, or from a combination of both. The type of exposure that would occur depends on the type of emergency.

**External Radiation Source:**Exposure can occur when all or part of the body absorbs radiation from an external radiation source without any direct contact with radiological materials. Exposure to an external source of radiation stops when a person leaves the area of the radiation source, the source is shielded, or the process causing exposure is halted.
	**Direct Contamination:** Exposure also can occur when a person is contaminated with radioactive particles, which can be external and/or internal.
	**External contamination**occurs when radioactive materials are deposited on external body parts such as skin, hair, and eyes, and clothes. External contamination stops when the radioactive material is removed by taking off contaminated clothing and completely washing off the contamination.
		**Internal contamination** occurs when radioactive materials are taken into the body by inhalation or ingestion, or through open wounds. The deposition of radioisotopes in organs results in local exposure. Internal contamination stops when the radioactive material decays, is eliminated from the body via natural processes, or is removed by medical countermeasures.Some medical countermeasures are available for treating the adverse health effects from exposure to radiation as well as for limiting or removing internal contamination to help prevent or minimize adverse health effects. In the event of a radiological or nuclear emergency, medical professionals will determine if MCMs are needed.

About Acute Radiation Syndrome (ARS)

Acute Radiation Syndrome is an acute illness caused by irradiation of the entire body (or most of the body) by a high dose of penetrating radiation in a short period of time, usually a matter of minutes.

Patients exposed to high doses of radiation will not be able to produce sufficient numbers of new white blood cells, red blood cells, and platelets, a condition called myelosuppression.

Two major clinical manifestations of radiation bone marrow injury are neutropenia (abnormally low level of neutrophils, a type of white blood cell) and thrombocytopenia (abnormally low level of platelets) that directly impact the survival of victims exposed to radiation. Severe neutropenia increases the risk of sepsis and death due to infections, while thrombocytopenia increases the risk of hemorrhage and death due to bleeding.

More about ARS:

Acute Radiation Syndrome (ARS): A Fact Sheet for the Public (CDC)
	Acute Radiation Syndrome: A Fact Sheet for Clinicians (CDC)MCMs to treat patients with radiation-induced myelosuppression following a radiological/nuclear incident (H-ARS)

Myelosuppression occurs when radiation damages the bone marrow. Suppression of the bone marrow blocks the production of blood cells. There are FDA-approved products that can help patients with H-ARS by facilitating recovery of bone marrow cells that develop into white blood cells, including neutrophils, which help fight off infections.

FDA-approved products that may be used to treat adult and pediatric patients acutely exposed to myelosuppressive doses of radiation, a condition known as Hematopoietic Syndrome of Acute Radiation Syndrome, or H-ARS:

Neupogen (filgrastim) – approved March 2015 [more info; product label (PDF, 1.2 MB)]
	Neulasta (pegfilgrastim) – approved November 2015 [product label (PDF, 1.7 MB)]
	Leukine (sargramostim) – approved March 29, 2018 [more info (PDF, 299 KB); product label (PDF, 786 KB)]
	NPLATE (romiplostim) – approved January 28, 2021 [product label(PDF, 684 KB)]
	Udenyca (pegfilgrastim-cbqv) – approved November 28, 2022 [product label (PDF, 460 KB)]; single-dose prefilled auto-injector presentation approved March 3, 2023 [product label (PDF, 1.3 MB)]Internal contamination

Internal contamination with radioisotopes occurs when radioactive materials are taken into the body by inhalation or ingestion, or through open wounds, and are transported into cells, tissues, and organs specific for the radioisotope, (e.g. lungs, kidneys, bone marrow) resulting in local exposure at that site of incorporation. Internal contamination stops when the radioactive material decays, is flushed from the body via natural processes, or is removed by MCMs called decorporation agents.

Decorporation agents

FDA-approved decorporation agents that may be used in radiation emergencies, to limit damage from internal contamination with specific isotopes, include:

Radiogardase (Prussian blue insoluble) capsules
	Pentetate calcium trisodium (Calcium-DTPA) injection and pentetate zinc trisodium (Zinc-DTPA) injectionThyroid blocking agent

Potassium iodide (KI) blocks the uptake of radioactive iodine into the thyroid gland*Also see: **Radiation Emergencies** (additional information about MCMs from FDA), and Medical Countermeasures (Treatments) for Radiation Exposure and Contamination, from CDC*

Guidance for industry

FDA works with medical product sponsors to clarify regulatory and data requirements necessary to move investigational products forward in development as quickly as possible.

FDA guidance documents related to radiation and nuclear preparedness include:

Draft guidance for industry: Acute Radiation Syndrome: Developing Drugs for Prevention and Treatment (April 2023) - submit comments by **July 19, 2023**
	Radiation Biodosimetry Medical Countermeasure Devices (PDF, 514 KB) April 2016
	Internal Radioactive Contamination – Development of Decorporation Agents (PDF, 177 KB) March 2006
	Calcium DTPA and Zinc DTPA Drug Products – Submitting a New Drug Application(PDF, 168 KB) August 2004
	Potassium Iodide Tablets Shelf Life Extension (PDF, 191 KB) – March 2004
	Prussian Blue Drug Products — Submitting a New Drug Application (PDF, 159 KB) January 2003
	KI in Radiation Emergencies – Questions and Answers (PDF, 161 KB) December 2002
	Potassium Iodide as a Thyroid Blocking Agent in Radiation Emergencies (PDF, 40 KB) December 2001
	Accidental Radioactive Contamination of Human Food and Animal Feeds: Recommendations for State and Local Agencies (PDF, 231 KB) August 1998*To learn more about guidance, or view more FDA guidance documents, see Search for FDA Guidance Documents*

Statements and updates

**April 19, 2023:**FDA announced availability of a draft guidance for industry, Acute Radiation Syndrome: Developing Drugs for Prevention and Treatment. The purpose of this draft guidance is to provide information and recommendations to assist sponsors and other interested parties in the development of drugs to prevent or treat acute radiation syndrome (ARS) caused by exposure to ionizing radiation from accidental or deliberate events. Generally, drugs developed for such indications will require approval under the regulations commonly referred to as the Animal Rule. Submit commentsby **July 19, 2023**.
	**March 3, 2023:** FDA approved (PDF, 296 KB) a new single-dose prefilled auto-injector presentation of Udenyca (pegfilgrastim-cbqv) to increase survival of adult and pediatric patients acutely exposed to myelosuppressive doses of radiation (Hematopoietic Syndrome of Acute Radiation Syndrome, or H-ARS) as could occur after a radiological or nuclear event. For more information, see the product label (PDF, 1.3 MB).
	**November 28, 2022:**FDA approved a new indication (PDF, 244 KB) for Udenyca (pegfilgrastim-cbqv) to increase survival of adult and pediatric patients acutely exposed to myelosuppressive doses of radiation (Hematopoietic Syndrome of Acute Radiation Syndrome, or H-ARS) as could occur after a radiological or nuclear event. Udenyca is the fifth FDA-approved medical countermeasure and first biosimilar that is indicated to increase survival in patients exposed to myelosuppressive doses of radiation. For more information, see the product label (PDF, 460 KB).
	**September 21, 2021:**FDA deactivated Import Alert #99-33 (IA) that has targeted certain food products from Japanese prefectures (Japan’s equivalent of a U.S. state) located near the damaged Fukushima Daiichi nuclear power plant since 2011. FDA will continue communication and collaboration with the Government of Japan to monitor and ensure the safety of food products exported from Japan to the U.S., as it has since the days following the 2011 disaster.
	**April 14, 2021:**FDA updated the page FDA Response to the Fukushima Daiichi Nuclear Power Facility Incidentwith new information after the Government of Japan announced it has decided to discharge into the ocean the wastewater that is currently being stored on site at the Fukushima Daiichi nuclear power plant.
	**January 28, 2021:**FDA approved a treatment to increase survival in adults and pediatric patients (including term neonates) acutely exposed to myelosuppressive doses of radiation (Hematopoietic Syndrome of Acute Radiation Syndrome [HS-ARS]). For more information about this treatment, please see the NPLATE (romiplostim) product label(PDF, 684 KB).
	**December 2, 2019:**Regulatory science update - FDA awarded a contract in September 2019 to the Wyss Institute for Biologically Inspired Engineering at Harvard University to advance the use of human organs-on-chips for medical countermeasure (MCM) development by demonstrating biomimicry and defining critical qualification criteria, helping to reduce the reliance on testing in animals. This work builds on past FDA-funded workthat led to the development of human models of acute radiation syndrome (ARS) in bone marrow, intestine, and lung organs-on-chips and the application of these tools to the evaluation of ARS MCMs.
	**March 29, 2018:**FDA approved a new indication for Leukine (sargramostim) to increase survival of adult and pediatric patients acutely exposed to myelosuppressive doses of radiation (Hematopoietic Syndrome of Acute Radiation Syndrome, or H-ARS) as could occur after a radiological or nuclear event. Leukine is the third FDA-approved medical countermeasure that is indicated to increase survival in patients exposed to myelosuppressive doses of radiation. *See Medical countermeasures for more information*Advisory Team

The Advisory Team enhances preparedness and response capabilities by providing protective action recommendations to government officials following accidents or incidents that result in the release of radioactive material to the environment. The Environmental Protection Agency (EPA), U.S. Department of Agriculture (USDA), and CDC also participate on this team, which has been active since 1996 and conducts regular national radiological emergency response exercises.
The Advisory Team deploys some of its members to the site of the incident, where they integrate into the Incident Command structure, typically at the State Emergency Operations Center and the Joint Field Office. Other members provide support from their headquarters locations to provide reachback for the field team, and to provide guidance to Incident Command while the field team is in transit to the incident site.
The Advisory Team provides guidance on a wide variety of topics consistent with the missions of the participating agencies. This includes recommendations on drinking water safety, agricultural contamination, human exposure, KI usage, population monitoring, long term recovery and many other issues.

Food safety

To protect the public from foods that may be contaminated with radioactive material as the result of a radiological or nuclear incident, FDA implemented the August 1998 guidance Accidental Radioactive Contamination of Human Food and Animal Feeds: Recommendations for State and Local Agencies (PDF, 231 KB).

Food contamination issues (also referred to as the ingestion pathway) play a prominent role in any discussion of large-scale radiological or nuclear emergencies.  The Advisory Team plays a significant role in providing guidance to decision-makers on assessments of food contamination and protective actions that may be taken to avoid excessive exposure to the public.

The FDA Winchester Engineering and Analytical Center (WEAC) serves as the lead for the radiological component of the Food Emergency Response Network(FERN) which is a consortium of federal and state laboratories having demonstrated capabilities for radiological analysis of foods to assess the level of contamination from rad/nuc emergencies.  In a large-scale event, WEAC would coordinate the processing of food samples across the network, with WEAC being the primary lab, and other laboratories providing surge capacity. The results of these analyses can be provided to local, state, and federal officials to help determine any actions that may be needed to protect the food supply.

Additional resources

Consumers | Healthcare providers | Governments (SLTT) | Communicators | Additional FDA emergency response info

****For consumers

Radiation emergencies (CDC)
	Types of radiation emergencies (CDC)
	FAQs about radiation emergencies (CDC), including info for pregnant or nursing women, and children
	CDC radiation infographics****For healthcare providers / public health professionals / responders

Radiation Emergency Medical Management (REMM) (HHS) – gives healthcare providers guidance on diagnosis and treatment during radiation emergencies (mobile app also available)
	Training: Medical Countermeasures for Radiation Exposure and Contamination (CDC)
	National Preparedness Month: Radiation Emergencies (CDC)
	Radiation emergency information for clinicians (CDC)
	Radiation Basics Made Simple training (CDC) – CE available
	Radiation Injury Treatment Network (RITN)****For state, local, territorial, and tribal (SLTT) governments

Potassium Iodide Tablets Shelf Life Extension (PDF, 191 KB) – FDA guidance for federal agencies and state and local governments, March 2004 *More about expiration dating extension*
	Accidental Radioactive Contamination of Human Food and Animal Feeds: Recommendations for State and Local Agencies (PDF, 231 KB) – FDA guidance, 1998
	Public Health Preparedness Capabilities for radiation emergencies (CDC)
	Radiological Terrorism: Tool Kit for Public Health Officials (CDC)
	National Alliance for Radiation Readiness (NARR)
	Public Health Radiological/Nuclear Preparedness Webinar (hosted by CDC, August 2017)
	Conference of Radiation Control Program Directors (CRCPD)
	Federal Radiological Monitoring and Assessment Center (FRMAC)
	Radiation Emergency Assistance Center/Training Site (REAC/TS)****For communicators

Communication and Media Tools for radiation emergencies (CDC)
	Myths of Radiation: Communicating in Radiation Emergencies (CDC video, 4:32)
	Protective Action Guide (PAG) Public Communication Resources (EPA)
	REMM info for public information officers (HHS)
	Radiation dictionary (CDC)****Additional FDA emergency response information

FDA Emergency Operations Plan Version 2.0 March 2014 - PDF (Nuclear/Radiological Annex, page 221-259)
	FDA Response to the Fukushima Daiichi Nuclear Power Facility Incident(2011, with 2014 and April 2021 updates)Archived information

Archived information is provided for reference. **Information in this section may be out-of-date.**

FDA Approves Drugs to Treat Internal Contamination from Radioactive Elements - August 2004
	FDA Approves First New Drug Application for Treatment of Radiation Contamination due to Cesium or Thallium - October 2003
	Questions and Answers on Prussian Blue – October 2003
	FDA Encourages New Applications for Drugs to Treat Internal Contamination from Radioactive Elements - September 2003
	FDA Encourages New Drug Application Submissions for Prussian Blue as a Treatment for Thallium or Radioactive Cesium Contamination – January 2003
	FDA Talk Paper: Guidance on Protection of Children and Adults Against Thyroid Cancer in Case of Nuclear Accident- December 2001Contact FDA

**Consumer inquiries**OCOD@fda.hhs.gov, 888-INFO-FDA

**Media inquiries**fdaoma@fda.hhs.gov, 301-796-4540

**Contact FDA’s Medical Countermeasures Initiative (MCMi)**AskMCMi@fda.hhs.gov

                                                                                  Content current as of:
      10/02/2023
              
              
Topic(s)
			  RadiologicalMCM Issues

          
                        Advanced Manufacturing
          Antimicrobial Resistance Information from FDA
          Ebola Preparedness and Response Updates from FDA
          FDA/DoD Collaborations
          FDA Mpox Response
          Medical Countermeasure Monitoring and Assessment
          Pediatric Medical Countermeasures
          Preparedness Information for Consumers
          Radiological and Nuclear Emergency Preparedness Information from FDA
          Smallpox Preparedness and Response Updates from FDA
          Zika Virus Response Updates from FDA
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