Toxic Priorities

Chemicals Hazardous to Human Health and the Environment:

Many toxic chemicals are too hazardous to safely produce and use. Some travel across the world via wind currents or international trade and are deposited without respect to national borders. Some chemicals can bio-accumulate in the food chain and others can remain in the environment for a long time. Growing chemical production means greater problems everywhere in the world. 

What Are POPs?

Persistent organic pollutants (POPs) are a class of highly hazardous chemical pollutants that are recognized as a serious, global threat to human health and to ecosystems. POPs are substances that specifically:

  • remain intact for exceptionally long periods of time (many years);
  • become widely distributed throughout the environment as a result of natural processes involving soil, water and, most notably, air;
  • accumulate in living organisms including humans, and are found at higher concentrations at higher levels in the food chain; and
  • are toxic to both humans and wildlife.

Some POPs are pesticides; some are industrial chemicals; and some are unintentionally produced byproducts that are formed during certain combustion and chemical industry processes. Some examples of POPs are DDT, lindane, PCBs and dioxins.

POPs are widely present in the environment in all regions of the world. Every person carries a body burden of POPs, mainly in his or her fatty tissues. Most fish, birds, mammals and other forms of wildlife are also contaminated with POPs.

POPs in the environment pollute the everyday food supply, especially fish, meat, butter and cheese. When people eat POPs-contaminated foods, the POPs accumulate in their fatty tissue. Mothers pass on POPs from their own bodies to their offspring. In humans and other mammals, POPs enter and contaminate the fetus while it is still in its mother’s womb. Since breast milk also contains POPs, infants are further exposed to POPs while nursing.* In non-mammal species, POPs are passed from the mother to offspring though the eggs.

POPs have the potential to harm humans and other organisms even at concentrations that are commonly found in ordinary foods. There is good medical evidence linking the following human illnesses and disabilities to one or more of the POPs:

  • Cancers and tumors including soft tissue sarcoma, non-Hodgkin’s lymphoma, breast cancer, pancreatic cancer and adult onset leukemia;
  • Neurological disorders including attention deficit disorder, behavior problems such as aggression and delinquency, learning disabilities and impaired memory;
  • Immune suppression;
  • Reproductive disorders including abnormal sperm, miscarriages, pre-term delivery, low birth weight, altered sex ratios in offspring, shortened period of lactation in nursing mothers and menstrual disorders; and
  • Other diseases including increased incidence of type II diabetes, endometriosis, hepatitis and cirrhosis.

POPs are most harmful to the developing fetus, causing health impairments such as neurological disorders and deficits, which continue throughout the child’s entire life. POPs are also particularly harmful to infants, children, women, the ill-nourished and some other populations.

* Note: It is recommended that mothers nonetheless continue to nurse their infants. Important nutrients that are contained in breast milk provide the infant with positive benefits that generally outweigh the negative impacts of the POPs. Therefore, mothers are still encouraged to breastfeed unless otherwise instructed by their physician.

‘Poisons Without Passports’

POPs concentrate in living organisms to levels where they can injure human health and the environment. POPs do their damage even in regions like the Arctic, far from where they are used or released. Additionally, they tend to accumulate in colder regions, and as global temperatures rise, most and more POPs will be released back into ecosystems.

POPs Common Characteristics

As a general rule, POPs have a number of common properties:

  • POPs are persistent in the environment. They resist degradation or breakdown through physical, chemical, or biological processes;
  • POPs generally are semi-volatile. They evaporate relatively slowly but when they enter the air, they travel long distances on air currents. They return to earth in rain and snow in the colder areas of the globe, resulting in their accumulation in regions such as the Arctic, thousands of kilometres away from their original sources;
  • POPs generally have low water solubility (they do not dissolve readily in water) and high lipid (fat) solubility (they do dissolve easily in fats and oils). Persistent substances with these properties bioaccumulate in fatty tissues of living organisms. In the environment, concentrations of these substances can increase by factors of many thousands or millions as they move up the food chain; and
  • POPs have the potential to injure humans and other organisms even at the very low concentrations at which they are now found in the environment, wildlife and humans. Some POPs in extraordinarily small amounts can disrupt normal biological functions, including the activity of natural hormones and other chemical messengers, triggering a cascade of potentially harmful effects.
Heavy Metals

Heavy metals are a loosely defined subset of elements with metallic properties and relatively high densities or relative atomic weights, some of which are dangerous to health and / or the environment.

IPEN’s work on heavy metals currently focuses on lead (specifically, eliminating lead from paint) and mercury (including sampling of mercury in fish and human hair and work on the international mercury treaty), although IPEN has also produced data about arsenic and cadmium via product testing with a x-ray fluorescence machine.

For more information on IPEN’s work on lead, please see our Eliminating Lead from Paint page.

For more information on IPEN’s work on mercury, please see our Mercury Treaty page and our Mercury in Fish and Human Hair page.


The term ‘nanotechnology’ describes materials, systems and processes that exist or operate at the extremely small scale of a few hundred nanometres or less. To put a nanometre in context: a strand of DNA is 2.5nm wide, a red blood cell is 7,000 nm and a human hair is 80,000 nm wide.

Nanomaterials are already used in a wide range of domestic, industrial and food products such as food additives, fuel catalysts, sports goods, specialty building equipment, electronics, household appliances, sunscreens and other products. There is uncertainty regarding the health impacts of nanoparticles. Substances that pose no risks in larger particle form can be toxic when occurring as nanoparticles. Surveys show that many companies do not conduct risk assessments and there is no requirement to make public any safety data that industry does generate. In vitro studies have shown that manufactured nanoparticles, which are in widespread commercial use including zinc, zinc oxide, silver, and titanium dioxide, pose new toxicity risks. Carbon nanotubes cause asbestos-like pathogenicity and the onset of mesothelioma in test mice. A small number of clinical studies suggest that nanoparticles and small microparticles that are not metabolised can over time result in granulomas, lesions (areas of damaged cells or tissue), cancer or blood clots. There is also evidence from animal studies that some nanoparticles can cross the placenta, posing particularly significant risks to developing embryos. Some nanoparticles have been shown to be toxic to environmental organisms and to transfer across species, indicating a concerning potential for bioaccumulation.

Nanomaterials are now used in food additives, fuel catalysts, sports goods, specialty building equipment, electronics, household appliances and other products. In coming years and decades, ‘next generation nanotechnology’ is forecast to bring more complex nanodevices, nanosystems, and nanomachines.

See IPEN materials related to nanotechnology in our Knowledge Center.

Ocean Pollutants

Marine pollutants are threatening the health of our oceans. Every day, a cocktail of intentional and unintentional chemical releases, as well as the unrelenting tidal wave of wastes, particularly plastic waste, enter our oceans and waterways.

Aquatic Pollutants Cover

Ocean pollutants include persistent organic pollutants (POPs), endocrine disrupting compounds (EDCs), mercury compounds, plastic wastes and related chemical compounds (e.g., BPA, phthalates), as well as other industrial and agricultural emissions. These toxic ocean pollutants disproportionately impact remote Arctic and Pacific Island communities, but they are a serious threat to the environment, food security, health, culture and human rights of all of us.

IPEN research has already demonstrated the impact of mercury pollution in the Asia Pacific region, and IPEN’s work on new POPs, through the Stockholm Convention POPs Review Committee, has highlighted the increasing detection of new POPs such as PFOS (perfluorooctane sulfonate) and PBDEs (polybrominated diphenyl ethers / brominated flame retardants) in the marine environment.

IPEN’s campaigns for non-combustion destruction of hazardous waste have highlighted the failures of countries to manage hazardous and plastic wastes, which results in ongoing chemical contamination of the oceans and predictions that there will be more plastic by weight than fish in our oceans by 2050.

In response to the increasing threat of marine pollutants in our oceans, IPEN has developed the ‘Addressing Ocean Pollutants Platform’ incorporating commitments to address identified problems. The platform is based on the principles of good chemical management; right-to-know, polluter pays, precaution and substitution, as well as the principles of social, environmental and intergenerational equity.

Read the platform here.

Ocean Pollutants Cover

Additionally, the 2018 comprehensive report, Ocean Pollutants Guide: Toxic Threats to Human and Marine Life, released by IPEN and the National Toxics Network (NTN), provided an up-to-date synthesis of data on toxic chemical ocean pollution, including hazardous pesticides, pharmaceuticals, persistent organic pollutants (POPs) like PCBs, plastics, microplastics, and heavy metals, and exposes their sweeping impacts on marine and human life. A valuable resource for policy makers, the report bridges information gaps between ocean health and chemical safety, and highlights critical policy opportunities for action by bringing simultaneous visibility to the role of invisible toxic chemicals and plastics.

Toxic Fracking

The term ‘fracking’ refers to hydraulic fracturing, but is now commonly used to describe the process of exploration and production of unconventional gas. Hydraulic fracturing (HF) is a process that involves injecting wells at high pressure with water, proppants, radioactive tracers and large quantities of chemical additives to fracture the formation and produce new cracks and pathways to help extract natural gas.

Fracking is used to extract natural gas in shale formations (‘shale gas’) or gas caught in limestone or sandstone, referred to as ‘tight gas’. HF is also used to retrieve coal bed methane (also known as coal seam gas), once the pressure within the coal seam has reduced and the methane is no longer easily accessible.

Amongst a multitude of other reasons, IPEN is concerned about fracking activities because of the chemical additives used during the process. Out of the 750 chemical products identified by the U.S. House of Representatives Committee on Energy and Commerce as being used in fracking, 650 contain hazardous substances (U.S. House of Representatives Committee on Energy and Commerce, Minority Staff, April 2011, Chemicals Used In Hydraulic Fracturing). These include carcinogens, neurotoxins and endocrine disruptors, including some with POPs characteristics.

Most of these hazardous substances have not been assessed for toxicity or persistence as they relate to the hydraulic fracturing process. Additionally, waste water produced by fracking is contaminated with these hazardous substances as well as other persistent and toxic contaminants, and is reused in numerous processes or released, partially “treated,” into waterways.

For information about toxic chemicals used in unconventional gas exploration and production, please see “Toxic Chemicals in Unconventional Gas Exploration and Production,” developed by National Toxics Network.



Women & Chemicals

Gender equality is a fundamental human right that is well-established in international law. Women face substantive barriers to the achievement of equality due to factors such as poverty, prejudice, violence, oppressive social and institutional structures, and lack of inclusion in decisions that affect their lives.[1] Women and girls should be free to realize their potential and rights in all aspects of their lives.

To ensure realization of the goal of gender equality (Sustainable Development Goal #5), in 2017 IPEN developed a Gender Initiative to empower women in our work to achieve a toxics-free future.

This Initiative was drafted by the IPEN Co-Chairs at that time (Dr. Olga Speranskaya and Pamela Miller) with comments and suggestions provided by a group of women gathered in California, USA, for IPEN’s 2016 Global Meeting, as well as from consultations with IPEN Participating Organizations. It builds on their ideas and achievements, and reflects global trends and accumulation of evidence about what should be done to close the existing gaps in gender equality.

IPEN’s Gender Initiative aims to enhance the role of women and women’s leadership in local, regional, national, and global efforts to reduce exposures to harmful chemicals and wastes. IPEN will continually work to expand the role of women and leadership of women within the network at all levels.

Slide from Gender Equality panel video (see link below)

Later in 2017, during the 3rd United Nations Environment Assembly (UNEA3), IPEN and the United Nations Environment Programme (UNEP) held a press conference to announce a new partnership to contribute to the work on Gender and Chemicals, through a focus on women. IPEN Co-Chair Dr. Olga Speranskaya opened the press conference with a statement on the partnership, reminding attendees: “There are nearly 4 billion women and girls on the planet. Despite the fact that women make up roughly half of the population and chemical exposure is widespread, knowledge of exposure routes and the true impacts of chemical exposures on women are difficult to determine because there is a lack of gender-disaggregated data.”