Current Directions &

Evolving Strategies

Looking Deeper:

How Today’s Research

Is Building a Safer Tomorrow

Current Directions & 

Evolving Strategies

Looking Deeper: 

How Today’s Research 

Is Building a Safer Tomorrow
Glossary of 

Acronyms

AZT Azidothymidine

BSC Board of Scientific Counselors

C. elegans Caenorhabditis elegans

CEBS Chemical Effects in Biological Systems

CDC Centers for Disease Control and Prevention

CPSC Consumer Product Safety Commission

DoD Department of Defense

EFV Efavirenz

EPA Environmental Protection Agency

FDA Food and Drug Administration

FTC Emtricitabine

HHS Department of Health and Human Services

HIV Human Immunodeficiency Virus

ICCVAM Interagency Coordinating Committee on the Validation of Alternative Methods

NCEH/ATSDR National Center for Environmental Health/Agency for Toxic Substances and Disease Registry

NCI National Cancer Institute

NCTR National Center for Toxicological Research

NICEATM NTP Interagency Center for the Evaluation of Alternative Toxicological Methods

NIEHS National Institute of Environmental Health Sciences

NIH National Institutes of Health

NIOSH National Institute for Occupational Safety and Health

NTP National Toxicology Program

OHAT Office of Health Assessment and Translation

OSHA Occupational Safety and Health Administration

PACs Polycyclic Aromatic Compounds

PBDEs Polybrominated Diphenyl Ethers

PFOA Perfluorooctanoic Acid

PFOS Perfluorooctane Sulfonate

RoC Report on Carcinogens

SACATM Scientific Advisory Committee on Alternative Toxicological Methods

TDF Tenofovir

Tox21 Toxicology in the 21st Century
Table of 

Contents

3 What We Do

4 What We’re Studying

12 How We’re Assessing Human Hazards

14 A Look Ahead

19 How We Work

21 How to Get Involved

22 Contact Information 

What 

We Do

National Toxicology Program 3

The NTP’s mission is to evaluate environmental substances of 

public health concern by developing and applying tools of modern 

toxicology and molecular biology.

The NTP is taking a close look at the thousands of substances in our environment, including substances used in personal 

care products, foods, prescription drugs, household cleaners and lawn care products, to identify any potential harm they 

might cause to human health.

Our focus is on prevention. As the largest government program in toxicology, we’re safeguarding the public health by 

identifying the potential toxic effects of these substances. We’re also working to advance our field, developing new study 

methods that will allow more efficient and cost-effective toxicology studies, both at the NTP and around the globe.

Our work falls into four main categories:

1. Coordinate toxicology testing programs throughout the Federal Government and provide a centralized and 

integrated evaluation of the effects of chemicals and other substances on human health.

2. Strengthen the science base in toxicology through our research and testing program. The program conducts and 

supports studies that fill significant gaps in toxicology research, help build understanding of the mechanisms of 

toxicity, or enhance the predictive value of future studies. 

3. Develop and validate improved testing methods, making it possible to study substances more quickly and 

cost-effectively. We’re working to develop mechanism-based testing methods that may require fewer test animals, 

test more substances faster and provide information that is more useful from a human health perspective.

4. Provide information about potentially toxic substances to health regulatory and research agencies, scientific

and medical communities, and the public so that they can make informed decisions and determine if interventions 

or reductions in exposure are needed to protect human health.

We’re continually evolving to remain on the cutting edge of scientific research and to develop and apply new 

technologies. To learn more about our current studies, see the “What We’re Studying” section. To learn more about 

how we’re changing the science of toxicology research, see the “A Look Ahead” section.
What 

We’re Studying

We are all affected by our environment—by the products and 

substances we come in contact with at home, at work and at 

play. We do not know the effects of many of these substances on 

our health, yet we may be exposed to them while manufacturing, 

distributing, using and disposing of them or when they become 

pollutants in our air, water or soil.

4 National Toxicology Program

The NTP is charged with evaluating high-priority products and substances for possible effects on human health. In 

our 30-plus years, we’ve studied over 2,500 substances, including industrial chemicals, pharmaceuticals, contaminants 

of finished drinking water, photoactive chemicals, dietary supplements and endocrine-disrupting substances. We’ve 

studied them for a variety of health-related effects, such as general toxicity, carcinogenicity (ability to cause cancer), 

genotoxicity (ability to damage genes), and effects on reproduction, development and the immune, cardiovascular and 

nervous systems. Our data have been used by regulatory agencies around the world when considering the need to 

regulate specific environmental substances to protect human health and the environment. 

Below are brief overviews of some of our current initiatives. In general, they are broad-based and investigate various 

health-related effects. For more detailed information, visit the NTP Web site at http://ntp.niehs.nih.gov.

Consumer Products

Radiofrequency radiation emissions from cellular phones

With over three billion in use worldwide, cellular phones are one of the most popular electronic devices ever introduced. 

Yet despite their staggering popularity, their possible effects on public health have not been fully explored. 

In the United States, cellular phones must meet current Federal Communication Commission guidelines on the emission 

of microwave radiation. However, these guidelines are only intended to protect the user from immediate injury due to the 

heat produced from this radiation. There is little information on whether long-term exposure to this radiation poses other 

health risks.

The NTP is working to provide this information, conducting studies that use laboratory animals and special chambers 

that simulate the exposures of cellular phone users. These studies will help clarify any potential health hazards, including 

cancer risk, and pave the way to better protect public health.
Sunscreens

Every year, millions use sunscreen to prevent sunburn and resulting skin damage. Specific chemicals in sunscreens can 

absorb or “block” ultraviolet radiation from the sun. Though these products are applied to the skin, sunscreen ingredients 

have been found in urine, indicating that they make their way into the body. Some data in the literature suggest that 

sunscreen ingredients may interact with the estrogen receptor and therefore have the potential to affect reproductive 

organ development and function. 

Using short-term studies, the NTP is currently assessing two of the most commonly used sunscreen ingredients, 

2-hydroxy-4-methoxybenzophenone and 2-ethylhexyl-p-methoxycinnamate, to characterize their potential interaction 

with steroid receptors. The NTP is also studying the effects of early life exposures on the developing fetus to determine 

if sunscreen ingredients are harmful, and to determine if they affect the offspring’s ability to reproduce in adulthood. 

These studies will provide useful information to both the Food and Drug Administration (FDA) and the public regarding 

potential hazards of sunscreen ingredients.

Perfluorinated compounds

Perfluorinated compounds such as perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) have been used 

since the 1950s to make a variety of consumer products. Their resistance to water, oil, heat and chemicals makes them 

very useful in a variety of products, including nonstick cookware, grease-resistant food packaging and fabrics that are 

resistant to stains, water and wrinkles. 

Although the use of these chemicals is decreasing, the same properties that make them commercially useful also make 

them very persistent, both in human tissue and in the environment. The NTP is collaborating with the Environmental 

National Toxicology Program 5
Protection Agency (EPA) to study how these chemicals behave inside the body, including potential effects on reproduction 

and development.

While much is known about the toxicity of PFOS and PFOA, less is known about other members of this chemical class. The 

NTP is exploring the use of tests in cells and isolated molecular targets to predict adverse responses to chemicals within 

this class. This study may ultimately help us to better understand the environmental health effects of the entire class of 

perfluorinated compounds.

Nanoscale materials

Nanoscale materials are defined as a set of substances where at least one critical dimension is less than about 

100 nanometers (a nanometer is one billionth of a meter). Because of their unique optical, magnetic, electrical and 

other properties, they hold great promise for use in electronics, medicine and other fields. Increasingly, nanoscale 

materials are appearing in cosmetics, foods, sunscreens, prescription drug products and commerce products. As 

a result, the potential exists for new and unanticipated exposures for which the impact on human health and the 

environment is not known. 

The NTP is engaged in a broad-based research program to address the potential human health hazards associated with 

their manufacture and use. Researchers are working to evaluate the toxicological properties of a representative cross 

section of several different classes of nanoscale materials: (1) metal oxides, (2) fluorescent crystalline semiconductors 

(quantum dots), (3) fullerenes (buckyballs) and (4) carbon nanotubes. We are using these classes as models to 

investigate if and how nanoscale materials can interact with biological systems. Key parameters of greatest concern 

relative to their potential toxicity are size, shape, surface chemistry and composition. Researchers are using studies in 

laboratory animals and cells, and mathematical models to evaluate and predict whether these materials can penetrate 

the skin, where they go in the body and what potential health effects they may cause. 

Flame retardants

Polybrominated diphenyl ethers (PBDEs) are widely used as flame retardants in fabrics, furniture and electronics. Over 

the past 25 years, they have been proven to be effective in reducing fire-related damage and injury. However, use of 

these chemicals has led to their accumulation in the environment, and evidence of significant concentrations in human 

and animal tissue has led to concern about possible toxicity, including carcinogenicity and reproductive toxicity. As a 

result, the NTP is currently evaluating several of the most commonly found PBDEs, as well as two other brominated flame 

retardants: tetrabromobisphenol A and tetrabromobisphenol A-bis(2,3-dibromopropyl ether).

The NTP is also studying other nonbrominated flame retardants, including antimony trioxide and tris(chloropropyl) 

phosphate, a proposed substitute for PBDEs in flame retardant applications.

These studies should provide information useful to the Consumer Product Safety Commission (CPSC) to ensure the safety 

of consumer products containing these chemicals.

Medicines and Therapeutics

Dietary supplements

Millions of Americans routinely take dietary supplements for health reasons, and their use is widespread and growing. 

The ingredients in dietary supplements vary and may include vitamins, minerals, herbs or other botanicals, amino acids, 

and substances such as enzymes and metabolites. Dietary supplements can also be extracts or concentrates and may 

be found in many forms, such as tablets, capsules, gels, liquids and powders.

The FDA regulates dietary supplements under a different set of regulations than those covering other foods and drug 

products. Under the Dietary Supplement Health and Education Act of 1994, dietary supplements do not need FDA approval 

6 National Toxicology Program
for safety or effectiveness before they are marketed. Once a product is marketed, the FDA has responsibility for monitoring 

safety and must show that a dietary supplement is not safe before it can take action to restrict its use or remove it from 

the marketplace. 

The NTP is working closely with the FDA to address questions about the safety of a broad range of dietary supplements 

and has completed studies for the following multipurpose and miscellaneous use supplements: Aloe vera, androstenedione, 

bitter orange, ephedra, Ginkgo biloba, ginseng, goldenseal, kava kava, milk thistle and senna. The NTP has ongoing studies 

for black cohosh, dong quai, Echinacea purpurea, evening primrose oil, Garcinia cambogia, gum guggul, green tea, 

resveratrol, Usnea lichen and valerian. 

National Toxicology Program 7
Human immunodeficiency virus (HIV) therapies

An estimated 35 million people worldwide are living with HIV, including about one million pregnant women who need 

treatment to prevent mother-to-child transmission of the virus during pregnancy, labor and delivery. Azidothymidine 

(AZT), the first FDA-approved anti-HIV agent, is often combined with other HIV drugs that target different aspects of viral 

replication. Because HIV drugs are administered in combination, the NTP is studying commonly used combinations (AZT, 

nevirapine, nelfinavir and/or lamivudine) to characterize any potential toxicity to the offspring. 

The World Health Organization has recommended the triple combination of tenofovir (TDF), emtricitabine (FTC) and 

efavirenz (EFV) as standard therapy for all HIV-positive individuals. While there is great benefit from this therapy, potential 

toxicity for the offspring is not known. The NTP is conducting studies to determine the potential effects of the TDF, FTC and 

EFV triple-combination therapy on fetal and postnatal development. The results of these studies can inform regulatory 

agencies worldwide of the impact of these drugs during pregnancy. 

Our Surroundings

Mold

New construction methods, better sealing and insulation in buildings, and natural disasters, such as hurricanes, have

all led to an increase in indoor mold levels. In recent years, there have been reports associating mold exposures with 

a variety of symptoms, including allergies and respiratory and neurological problems.

The NTP is currently conducting studies to better understand how exposure to mold may cause disease. Specific areas 

under study include:

•	 Fungal organisms that may be causing human health effects

•	 Target organs for fungal toxicity

•	 Dose-dependent effects, with particular emphasis on respiratory, immune and neurological end points

•	 Identification of biomarkers of exposure and effects

These studies will help us to better understand the causes of these symptoms, with the ultimate goal of creating

healthier buildings and reducing mold-related health issues.

Polycyclic aromatic compounds

Polycyclic aromatic compounds (PACs) are a large class of widespread environmental contaminants. PACs occur naturally 

in crude oil or are created and released into the environment through the burning of organic material such as fossil fuels. 

People can be exposed to PACs by eating certain foods (e.g., chargrilled meat, smoked fish), breathing contaminated air 

or handling tainted soil. People are exposed not to single PACs but to complex mixtures of PACs that differ depending on 

the source of the exposure and other factors (such as sunlight or weathering). 

Some substances of the PAC class are known human carcinogens; animal studies have shown that certain PACs can 

cause toxicity to immune, reproductive and other systems. However, the vast majority of PACs have not been evaluated. 

More research is needed to understand the combined effects of multiple PACs. 

The NTP is studying PACs to gain a better understanding of the toxicity of both individual PACs and PAC mixtures, 

and how environmental exposures to PACs may affect human health. 

8 National Toxicology Program

Food

The NTP is conducting studies of several food constituents and flavorings to help the FDA determine whether their 

presence in food is harmful. One such constituent is furan, a by-product of some chemical manufacturing processes, 

which is sometimes reported to be found in canned or jarred foods such as soups, sauces, beans, pasta meals and baby 

foods. It appears to form as a result of heat treatment techniques used to process and preserve foods. Furans are of 

concern because they are considered carcinogenic based on studies in laboratory animals at high doses. 

Our Workplace

Occupational exposures

The NTP is studying a variety of occupational chemicals to help the National Institute for Occupational Safety and Health

(NIOSH) better understand the risks they pose to workers, develop exposure limits for workers and help create safer 

working environments for millions of workers in the United States. The NTP is currently testing a variety of substances to 

which workers in certain occupations are exposed every day. These substances include:

•	 Abrasive blasting materials: Safer alternatives to silica sand are being tested, including coal slag, garnet,

crushed glass and specular hematite.

•	 Artificial butter flavoring, diacetyl and acetoin: Increased incidences of the lung disease bronchiolitis

obliterans and other forms of respiratory impairment have been reported among workers in the microwave

popcorn industry. Several studies suggest that exposure to volatile constituents of artificial butter flavoring

released during the production process is the greatest risk factor. Diacetyl and acetoin are two main volatile 

components of the flavoring.

•	 1-Bromopropane: An industrial chemical that has replaced ozone-depleting chemicals such as 	 	 	 	

hydrochlorofluorocarbons and chlorinated solvents for metal cleaning and degreasing.

•	 Metalworking fluids: Complex mixtures of chemicals that are used by millions of workers for cutting, milling, stamping, 	 	

drilling and grinding metal. The NTP will evaluate several commercial products.

•	 Welding fumes: Fumes generated by the process of joining or cutting pieces of metal by heat, pressure or

both. NIOSH has developed a robotic system to generate fumes similar to those found in the workplace.

Researchers at NIOSH are using artificial human lung fluids to study the persistence of tungsten oxide fibers formed during 

the processing of tungsten-containing ores and assessing exposure of workers to these fibers in tungsten refining and 

manufacturing operations. As part of the NTP’s research on nanomaterials, NIOSH scientists are characterizing workplace 

exposure to selected engineered nanoparticles.

10 National Toxicology Program

How We’re Assessing 

Human Hazards

The NTP maintains a number of activities to evaluate the 

potential for adverse effects on human health from exposure 

to substances in our environment. The reports from these 

health hazard evaluations provide critical information needed 

by Federal, state and local health regulatory and research 

agencies to conduct formal risk assessments.

Health Assessment and Translation

The NTP is committed to studying non-cancer health effects of potentially harmful substances through the Office 

of Health Assessment and Translation (OHAT). OHAT conducts literature-based evaluations to assess evidence that 

substances in our environment cause adverse health effects. For example, OHAT has studied the potential developmental 

effects of cancer chemotherapy during pregnancy and health effects of low-level lead exposure in children and adults. 

OHAT also organizes workshops and webinars to address emerging environmental health issues such as a workshop on 

the role of environmental chemicals in the development of diabetes and obesity. 

OHAT is applying systematic review methodology to address questions in environmental health and has developed 

a framework for systematic review and integration of scientific evidence for carrying out literature-based evaluations 

on environmental health topics. Such a framework enhances the transparency and quality of how OHAT reaches and 

communicates conclusions from its evaluations.

For every project, OHAT welcomes opportunities for external scientific, public and interagency inputs. The results of 

OHAT’s work are published in a variety of formats, including NTP monographs, state-of-the-science workshop reports 

and peer-reviewed journal publications. For more information about ongoing projects and the full list of reports, visit 

http://ntp.niehs.nih.gov/go/ohat.

12 National Toxicology Program
The Report on Carcinogens

The Report on Carcinogens (RoC) is one of the world’s leading compilations of data on agents, substances, mixtures 

and exposure circumstances that may pose a cancer risk to humans. First requested by Congress in 1978, it is published 

every two years.

The RoC lists substances that are “known” or “reasonably anticipated” to cause cancer in humans and to which 

a significant number of people living in the United States are exposed. It combines data from both Federal and 

nongovernmental sources into one document, including:

•	 The carcinogenicity, genotoxicity and biological mechanism (modes of action in the body) of the listed substance in

humans and/or animals

•	 The potential for human exposure to these substances

•	 Federal regulations to limit exposures

Each edition of the report is cumulative and includes substances newly reviewed, in addition to those listed in previous 

editions. The most recent edition of the RoC is available on the RoC Web site at http://ntp.niehs.nih.gov/go/roc.

The NTP follows a formal, multistep process for review of candidate substances nominated for listing in or removal from 

the RoC. To find out what’s under review, visit the RoC Web site. 

National Toxicology Program 13
A Look 

Ahead

In addition to its current portfolio of toxicological studies, the NTP 

is working to make the future of toxicology research more efficient, 

allowing for a much greater number of substances to be tested and 

providing results that are more useful for human risk assessment.

14 National Toxicology Program

The NTP and other Federal agency partners are working to change toxicology from an observation-based science using 

disease-specific models to a predictive science that uses mechanism-based biological observations. The NTP Roadmap 

supports this goal through three key initiatives:

1. Refine traditional toxicology assays

2. Develop rapid, mechanism-based, predictive screens for environmentally induced diseases

3. Improve the overall utility of NTP products for public health decisions

To that end, the NTP is developing a number of promising new testing approaches that are advancing the future of 

toxicology research, both at the NTP and elsewhere.

Alternative Toxicological Methods

A primary goal for the NTP is to advance the science of toxicology by developing toxicological testing methods that 

improve on current tests by:

•	 Predicting human health hazards more precisely

•	 Saving time and money

•	 Reducing, refining (by causing less pain and distress) or replacing animal use in testing, where feasible

To help reach these goals, two groups are specifically charged with addressing the development and use of alternative 

methods in regulatory safety testing.
The Interagency Coordinating Committee on the Validation of Alternative Methods (ICCVAM) is a Federal 

committee charged with coordinating and promoting the development, validation, acceptance and national and 

international harmonization of new, revised and alternative test methods. ICCVAM consists of representatives from 

15 regulatory and research agencies that generate or use toxicological testing data to safeguard the health of people, 

animals and the environment.

ICCVAM has evaluated many tests, some of which have been adopted or approved by U.S. regulatory agencies. For 

other tests, ICCVAM has recommended efforts to further characterize or improve their usefulness for regulatory safety 

testing. ICCVAM convenes workshops and expert panel meetings to assess research, development and validation 

efforts for alternative toxicological test methods. The results of ICCVAM evaluations are published in peer-reviewed 

reports or journals.

National Toxicology Program 15
The NTP Interagency Center for the Evaluation of Alternative Toxicological Methods (NICEATM) administers ICCVAM 

and provides scientific and operational support for ICCVAM-related activities. NICEATM also conducts validation studies 

to evaluate new or revised alternative methods for toxicity testing. In addition, it provides support in data analysis for the 

Toxicology in the 21st Century (Tox21) consortium, an ongoing collaboration among Federal agencies to characterize the 

potential toxicity of chemicals by using cells and isolated molecular targets instead of laboratory animals. 

NICEATM is working with ICCVAM to develop alternative test methods for regulatory use. These include toxicity tests 

for short-term exposure to a substance by ingestion or skin contact, and safety tests for biologics, such as vaccines. 

ICCVAM and NICEATM communicate with partners and the public to foster acceptance and use of alternative 

toxicological methods by regulators and the regulated community. ICCVAM also works with other international 

organizations to promote cooperation, with the goal of more rapid acceptance of new safety testing alternatives 

to animal testing worldwide. 

Non-Mammalian Model Systems

The NTP is continuing to explore the use of non-mammalian species as potential alternative models for toxicology testing. 

The NTP is currently evaluating two model organisms, Caenorhabditis elegans (C. elegans) and zebrafish, for assessing 

the potential toxic effects of chemicals on development and the immune and nervous systems of multicellular organisms. 

C. elegans is a roundworm about 1 mm in length that lives freely in soil and feeds on bacteria; zebrafish are vertebrate 

organisms that develop within a week most of the major organ systems present in mammals.

Both organisms hold promise as practical and efficient test models for several reasons:

•	 Both have short life cycles, are easy and inexpensive to maintain, and have genetic variants that are readily available

•	 A great deal of information is available on both organisms, including their complete genomic sequence, as well as

detailed information on their cellular and developmental biology

•	 Their molecular and biochemical changes following chemical exposure appear to be similar to those seen in

laboratory studies that use rodents

The use of these alternative animal models is consistent with NTP’s strategy to reduce the number of mammals used 

in testing. Several toxicology tests that evaluate developmental toxicity, immunotoxicity and neurotoxicity have been 

developed. While both organisms are still under study, they hold a great deal of promise for faster, more cost-effective 

toxicology studies.

16 National Toxicology Program
High-Throughput Screening and Tox21

The NTP is working to develop higher throughput toxicology testing methods that will allow researchers to evaluate a 

large number of substances faster. New automated processes can screen tens of thousands of substances for biological 

activity using cells and isolated molecular targets. The information from these studies will help the NTP do the following:

•	 Identify mechanisms of chemical toxicity for further study

•	 Develop models that predict how substances might react in biological systems

•	 Prioritize substances for further toxicological study

The Tox21 consortium uses a high-throughput screening approach that shows great promise for changing toxicology 

into a predictive science. This consortium is a collaboration of the NTP, the National Institutes of Health's National Center 

for Advancing Translational Sciences, the EPA's National Center for Computational Toxicology and the FDA. The Tox21 

partners work together to develop, validate and translate innovative high-throughput screening methods to characterize 

the impact of chemicals on key steps in toxicity pathways. The goal of Tox21 is to use high-throughput screening methods 

to more accurately predict the effects of chemicals on human health and the environment. The Tox21 initiative also offers 

the potential for decreased use of animals in toxicity testing. 

Population-Level Differences 

in Response to a Toxicant

Human populations have great genetic diversity and vary in responses to environmental factors. However, almost all 

toxicology studies utilize mouse models that are genetically homogenous. Using genetically diverse mouse populations 

for toxicology studies can provide better models for the variation in response to a given toxicant in the human population. 

The NTP is working to identify the genetic reasons for differences in disease and disease incidence caused by toxic 

substances among different ages, sexes, ethnicities and other populations. The NTP is evaluating known toxicants in 

genetically diverse mouse populations to get an indication of the variation in response to each toxicant across the 

different mouse populations. This research will ultimately lead to greater insight into the genes and pathways involved 

in toxicity, and to better strategies for predicting the potential toxicity of substances we encounter in our daily lives.

National Toxicology Program 17
National Toxicology Program

(Headquartered at the NIEHS)

Director

NIEHS and NTP

FDA

NCTR

NIH

NIEHS

CDC

NIOSH

Assistant Secretary for Health, HHS

Policy Oversight

NTP Executive 

Committee

• CPSC

• DoD

• EPA

• FDA

• NCEH/

 ATSDR

• NCI

• NIEHS

• NIOSH

• OSHA

External Science 

Oversight and 

Review

• NTP Board of Scientific 

 Counselors

• Scientific Advisory 

 Committee on 

 Alternative Toxicological 

 Methods

• Special Emphasis Panels
How 

We Work

National Toxicology Program 19

NTP Structure

The NTP is made up of three core agencies: 

1. National Center for Toxicological Research (NCTR). The NCTR is part of the FDA.

2. National Institute of Environmental Health Sciences (NIEHS). The NIEHS is part of the National Institutes

of Health (NIH).

3. National Institute for Occupational Safety and Health (NIOSH). NIOSH is part of the Centers for Disease

Control and Prevention (CDC).

These agencies work together to provide the resources that support the NTP. The NTP’s operations are headquartered

at the NIEHS, and the NIEHS Director also serves as Director of the NTP. The NTP Director reports to the Assistant Secretary 

for Health of the Department of Health and Human Services (HHS) on issues and activities related to the NTP.

There are also several groups that provide oversight and advice to the NTP. They include:

NTP Executive Committee: This committee provides policy oversight to the NTP. It is composed of the heads (or their 

designees) of Federal health research and regulatory agencies, including the CPSC, Department of Defense (DoD), EPA, 

FDA, National Center for Environmental Health/Agency for Toxic Substances and Disease Registry (NCEH/ATSDR), National 

Cancer Institute (NCI), NIEHS, NIOSH and Occupational Safety and Health Administration (OSHA).

NTP Board of Scientific Counselors (BSC): This committee provides scientific oversight to the NTP. It is a federally 

chartered committee whose members are appointed by the Secretary of the HHS. The BSC meets once or twice each 

year, and meetings are open to the public.

Scientific Advisory Committee on Alternative Toxicological Methods (SACATM): This federally chartered committee 

provides advice to NICEATM and ICCVAM on priorities and directives related to the development, validation, scientific 

review, regulatory acceptance of new or revised alternative test methods, and on ways to foster partnerships and 

communication with interested parties. Its members are appointed by the NIEHS Director. SACATM meets once or twice 

each year, and meetings are open to the public.

Special emphasis panels are convened as needed to provide independent scientific peer review and advice to the NTP. 

These panels help ensure transparent, unbiased and scientifically rigorous input to the program. This input helps the NTP 

make credible decisions about human health hazards, set research and testing priorities and evaluate test methods for 

toxicity screening.

How NTP Studies and Evaluations Work 

The NTP has a broad mandate to evaluate the toxicity of substances of public health concern, which it accomplishes 

through research and testing activities and evaluations of the scientific literature. The NTP selects substances to examine 

through a nomination process that is open to all interested individuals and groups, and strives to maintain a balanced 
portfolio. Research and testing activities and literature-based evaluations are initiated as time and 

resources permit. 

NTP studies follow approaches accepted by Federal regulatory authorities and evaluate substances for a variety of 

health-related effects, including general toxicity, reproductive and developmental toxicity, genotoxicity, immunotoxicity, 

neurotoxicity and carcinogenicity. In recent years, the NTP has expanded its capabilities to examine effects of chemicals 

on the developing fetus, as well as the offspring’s ability to reproduce. The NTP studies both single chemicals and 

mixtures. Outcomes from the studies are assessed against established criteria for identification of potential human health 

hazards. Although these studies generally use rodent models, the NTP is exploring the use of non-mammalian species 

and cellular and molecular targets as alternative models.

NTP evaluations of the published literature focus on identification of both cancer and non-cancer hazards. Using 

structured approaches, the NTP evaluates the quality of the evidence for reported health effects to determine whether 

exposure to a substance affects human health. In parallel, the NTP is pursuing the use of free, web-based, publicly 

available data management resources that can be used to enhance our ability to analyze and evaluate results 

across studies. 

The NTP hosts national and international workshops to discuss the state of the science and advance environmental 

health sciences. The NTP also communicates its findings and activities by attending conferences and hosting webinars 

and symposiums. 

The results from NTP research and testing activities and literature-based evaluations are peer reviewed by external 

experts and published in various NTP reports or monographs, or peer-reviewed journals. Completed reports are available 

on the NTP Web site at http://ntp.niehs.nih.gov/go/reports.

NTP Resources

The NTP provides a variety of resources for public use, such as databases, atlases and the NTP Archives. The NTP 

maintains three databases: Chemical Effects in Biological Systems (CEBS) Database, which houses environmental health 

science study information and data; DrugMatrix®, a toxicogenomics reference database with accompanying extensive 

frozen tissue archives and informatics system; and ToxFx, an automated toxicogenomics analysis application. These 

databases can be found at http://ntp.niehs.nih.gov/go/datasearch. 

The NTP provides digitized images of a variety of lesions through the Digitized Atlas of Mouse Liver Lesions 

(https://www.niehs.nih.gov/research/resources/liverpath/index.cfm) and the NTP Nonneoplastic Lesion Atlas 

(http://ntp.niehs.nih.gov/nnl). 

NTP Archives is a state-of-the-art facility that houses NTP’s expansive collection of research specimens and 

supporting data from NTP studies. To gain access to the archives, submit a request to the NTP Archives 

(see "Contact Information" section).

NTP Training Programs 

The NTP offers postdoctoral training fellowships in a wide range of research and testing activities and literature-based 

evaluations. The postdoctoral training program funds fellowships at the NTP for up to five years. Information about these 

programs is available on the NIEHS Web site at http://www.niehs.nih.gov/careers/research/postdoc-training/index.cfm.

20 National Toxicology Program
How to 

Get Involved

The NTP welcomes feedback from the public and all interested 

parties. If you would like more detailed information about our work, 

would like to nominate a substance for evaluation, or have any other 

concerns, these are the best places to reach us:

National Toxicology Program 21

The NTP Office of Liaison, Policy and Review constantly seeks input from the public and all interested parties. Inquiries 

and comments are always welcome. Contact this office for general inquiries and requests for information (see "Contact 

Information" section).

The NTP Web site offers searchable access to NTP activities and other information. Data from NTP studies are available 

with download and search capabilities. The NTP also offers a free online listserv that provides subscribers with email 

notification of new NTP publications and upcoming events, including advisory committee meetings, peer reviews, expert 

panel meetings and workshops. To subscribe to this listserv, visit the NTP Web site at http://ntp.niehs.nih.gov/go/231.

The NTP welcomes the nomination of substances for evaluation by NTP programs in research and testing, literature-based 

evaluations or alternative test methods. Nominations can be made through the NTP Web site at http://ntp.niehs.nih.gov/

go/27911.

Public comments are welcome on all NTP activities. Public comments can be sent directly to the specific NTP program 

(see "Contact Information" section) or through the NTP Web site at http://ntp.niehs.nih.gov/go/opensolicitations.

Central Data Management is a resource for locating substance-specific study information and other NTP documents on 

request, including the NTP Annual Report, NTP study status reports, fact sheets, background documents for substances 

nominated to the NTP for study, and copies of draft NTP reports and monographs. Access these reports on the NTP Web 

site or contact Central Data Management (see "Contact Information" section).
Contact 

Information

Primary Contact

NTP Office of Liaison, Policy and Review

NIH/NIEHS

P.O. Box 12233, MD K2-03

Research Triangle Park, NC 27709

(919) 541-7539

Email: wolfe@niehs.nih.gov

Program Contacts

Central Data Management

NIH/NIEHS

P.O. Box 12233, MD K2-05

Research Triangle Park, NC 27709

(919) 541-3419

Email: cdm@niehs.nih.gov

NTP Archives

NIH/NIEHS

P.O. Box 13566

Research Triangle Park, NC 27709

(919) 541-4613

Email: herbert1@niehs.nih.gov

NTP Interagency Center for the Evaluation of 

Alternative Toxicological Methods

NIH/NIEHS

P.O. Box 12233, MD K2-16

Research Triangle Park, NC 27709

(919) 316-4729

Email: niceatm@niehs.nih.gov

Web site: http://ntp.niehs.nih.gov/go/niceatm

Office of Health Assessment and Translation

NIH/NIEHS

P.O. Box 12233, MD K2-04

Research Triangle Park, NC 27709

(919) 541-5021

Email: thayer@niehs.nih.gov

Web site: http://ntp.niehs.nih.gov/go/ohat

Office of Nominations and Selection

NIH/NIEHS

P.O. Box 12233, MD K2-02

Research Triangle Park, NC 27709

(919) 541-5710

Email: ntpnomin@niehs.nih.gov

Web site: http://ntp.niehs.nih.gov/go/nom

Office of the Report on Carcinogens

NIH/NIEHS

P.O. Box 12233, MD K2-14

Research Triangle Park, NC 27709

(919) 316-4637

Email: lunn@niehs.nih.gov

Web site: http://ntp.niehs.nih.gov/go/roc

22 National Toxicology Program
Headquartered at the

National Institute of Environmental Health Sciences

National Institutes of Health

P.O. Box 12233

Research Triangle Park, NC 27709

Web site: http://ntp.niehs.nih.gov

Public Health Service

U.S. Department of Health and Human Services

National Toxicology Program
Updated 2014

For information about the NTP, go to http://ntp.niehs.nih.gov

U.S. Department of Health and Human Services

Printed March 2014