Glossary

B

Bioaccumulation

The gradual buildup of chemicals in living organisms over time. When a substance is absorbed faster than it is broken down or excreted, it accumulates in tissues, potentially reaching harmful concentrations. This is particularly concerning for persistent chemicals like PFAS and heavy metals that move up the food chain.

Biomonitoring

The practice of measuring chemicals or their metabolites in the human body, typically through blood, urine, hair, or breast milk samples. Biomonitoring studies help researchers understand real-world chemical exposures across populations and track trends over time.

BPA (Bisphenol A)

An industrial chemical used since the 1950s to make certain plastics and resins, commonly found in food containers, water bottles, and can linings. BPA is a known endocrine disruptor and has been linked to a range of health concerns. Learn more →

C

Carcinogen

A substance, organism, or agent capable of causing cancer. Carcinogens are classified by agencies such as the International Agency for Research on Cancer (IARC) and the U.S. National Toxicology Program (NTP) based on the strength of scientific evidence linking them to cancer development.

CAS Number

A unique numerical identifier assigned to every chemical substance by the Chemical Abstracts Service. CAS numbers are the global standard for unambiguously identifying chemicals regardless of their common or trade names, making them essential for safety data lookups and regulatory compliance.

E

Endocrine Disruptor

A chemical that can interfere with the body's hormonal (endocrine) system, even at very low doses. Endocrine disruptors can mimic, block, or alter the actions of natural hormones, potentially leading to developmental, reproductive, neurological, and immune effects. Common examples include BPA, phthalates, and certain pesticides. Browse chemicals →

EPA Safer Choice

A voluntary U.S. Environmental Protection Agency certification programme that identifies products made with ingredients that are safer for human health and the environment. Products bearing the Safer Choice label have been reviewed to meet strict safety criteria. Learn more →

EWG Verified

A certification mark from the Environmental Working Group indicating that a product meets their strictest standards for health and transparency. EWG Verified products avoid ingredients on the EWG's "unacceptable" list and must fully disclose all ingredients. Learn more →

F

Formaldehyde

A colourless, strong-smelling gas used in building materials, household products, and as a preservative. Classified as a known human carcinogen by IARC, formaldehyde exposure can also cause respiratory irritation and skin sensitisation. Learn more →

G

GRAS (Generally Recognized as Safe)

A U.S. Food and Drug Administration (FDA) designation indicating that a chemical or substance added to food is considered safe by qualified experts. GRAS status can be determined by the FDA or through a manufacturer's own assessment, which has led to some debate about the rigour of the process.

Greenwashing

The practice of making misleading or unsubstantiated claims about the environmental or health benefits of a product. Greenwashing can include vague language like "all-natural" or "chemical-free," imagery that implies purity without evidence, or highlighting one green attribute while ignoring other harmful ingredients.

I

INCI (International Nomenclature of Cosmetic Ingredients)

An internationally standardised system for naming cosmetic ingredients. INCI names appear on product labels and allow consumers and professionals to identify ingredients consistently across brands and countries, regardless of marketing names. Guide: How to Read Labels →

M

MADE SAFE

A third-party certification that screens products against a comprehensive database of known harmful substances, including chemicals linked to cancer, developmental toxicity, and environmental damage. MADE SAFE certified products have been evaluated for safety across the entire ingredient list. Learn more →

Microplastics

Tiny plastic particles less than 5 millimetres in diameter, found in a wide range of consumer products including cosmetics, cleaning agents, and synthetic textiles. Microplastics persist in the environment, accumulate in waterways and food chains, and are increasingly detected in human blood and tissue.

N

Neurotoxin

A substance that is toxic to the nervous system. Neurotoxins can damage or destroy nerve tissue, potentially causing symptoms ranging from headaches and cognitive difficulties to serious neurological disorders. Developing brains in children and foetuses are especially vulnerable to neurotoxic exposure.

O

OEKO-TEX

An independent testing and certification system for textiles, ensuring that fabrics and materials are free from harmful substances. The OEKO-TEX Standard 100, for example, tests for a wide range of regulated and unregulated chemicals at every stage of production. Learn more →

Off-gassing

The release of volatile chemicals from solid or liquid products into the surrounding air at room temperature. Common sources include new furniture, paint, mattresses, and flooring. Off-gassing can contribute to poor indoor air quality and may trigger respiratory symptoms, especially in poorly ventilated spaces.

P

Parabens

A group of synthetic preservatives widely used in cosmetics, personal care products, and some foods to prevent bacterial and fungal growth. Parabens can mimic oestrogen in the body, raising concerns about potential links to hormone disruption and breast cancer. Learn more →

Persistent Organic Pollutant (POP)

A class of toxic chemicals that resist environmental degradation and persist in the ecosystem for years or decades. POPs bioaccumulate in the food chain, can travel long distances through air and water, and are linked to serious health effects including cancer, reproductive harm, and immune system damage. They are regulated internationally under the Stockholm Convention.

PFAS (Per- and Polyfluoroalkyl Substances)

A large group of synthetic chemicals often called "forever chemicals" because they do not break down in the environment. Used in non-stick coatings, waterproof textiles, food packaging, and firefighting foams, PFAS are linked to cancer, immune suppression, and hormonal disruption. Learn more →

Phthalates

A group of chemicals used to make plastics more flexible and as solvents in personal care products such as fragrances and nail polish. Phthalates are endocrine disruptors associated with reproductive harm, developmental effects, and respiratory issues. Learn more →

R

REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals)

The European Union's comprehensive regulatory framework for managing chemical substances. REACH requires manufacturers and importers to register chemicals, evaluate their risks, and restrict or authorise the use of substances of very high concern. It is one of the most stringent chemical safety regulations in the world.

S

SDS (Safety Data Sheet)

A standardised document that provides detailed information about a chemical substance or mixture, including its hazards, safe handling and storage procedures, emergency measures, and disposal guidelines. SDSs are required by law for hazardous chemicals in workplaces and are a key resource for understanding chemical risks.

Surfactant

A substance that lowers the surface tension between liquids, or between a liquid and a solid. Surfactants are the primary active agents in soaps, detergents, and cleaning products, helping water to mix with oils and dirt for effective cleaning. Some synthetic surfactants can be irritating to skin or harmful to aquatic life.

T

Triclosan

An antibacterial and antifungal agent once widely used in soaps, toothpaste, and household products. Triclosan has been linked to hormone disruption, antibiotic resistance, and environmental harm. It was banned from over-the-counter antiseptic wash products in the U.S. in 2016. Learn more →

V

VOCs (Volatile Organic Compounds)

A broad group of carbon-based chemicals that easily evaporate at room temperature, releasing gases into the air. Common sources include paints, varnishes, cleaning supplies, and building materials. VOCs can cause eye, nose, and throat irritation, headaches, and long-term health effects with prolonged exposure. Learn more →