Guide to Less Toxic Products

Environmental Health Association of Nova Scotia

Chemical Hazards

Types of Hazards
   General Hazards
   Personal Care Hazards
   Household Cleaning Hazards
Websites about Hazardous Substances and their Health Effects

Types of Hazards

The hazards of ingredients in personal care and household products are varied. The following are some of the most common types of hazards, many of which will not become apparent for many years. Many chemicals have more than one adverse health effect.

Carcinogen: Cancers result from genetic alterations which generally develop years after exposures. Substances may be categorized as known, suspected or possible human carcinogens, based on the amount and type of research done on them.

Developmental toxin: A substance which has an adverse affect on a developing child, sub-category of reproductive toxin. Developmental toxins are also known as teratogens. They usually result from pre-natal exposure experienced by the mother, but can also result from pre-natal exposure by the father, or post-natal exposure of a developing child.

Endocrine or hormone toxin: In recent years, scientists have discovered that certain commonly used chemicals can disrupt our delicate endocrine systems. The endocrine system produces hormones in a variety of organs known as endocrine glands. These hormones travel in the bloodstream carrying messages from one part of the body to another. Endocrine disrupting chemicals can upset this communication system in a variety of ways. They can mimic natural hormones and send false messages, or block hormone receptors that receive messages. While researchers are only beginning to understand the health effects of these chemicals, they have already observed that hormone disruptions can result in damage to the brain, immune and reproductive systems.
The unborn child is particularly susceptible. Miniscule amounts of chemicals that may not harm an adult can have devastating effects at critical stages of development of the fetus. There is evidence that hormone-disrupting chemicals can result in learning disabilities, testicular cancer, impaired thyroid function, declining sperm counts and male genital defects.
Because hormone-disrupting chemicals mimic estrogen, it is suspected they are linked to the growing incidence of breast cancer. Very few ingredients are tested for reproductive or developmental effects caused by hormone disrupting chemicals.

Immune system toxin: A substance which has an adverse effect on the functioning of the immune system. Altered immune function may lead to increased incidence or severity of infectious diseases or cancers. Allergens are considered to be immunotoxicants, which can cause hypersensitivity reactions like asthma, rhinitis and anaphylaxis, as well as allergies.

Liver toxin: The liver functions as a center for metabolism, processing chemicals we are exposed to so they can be utilized, detoxified or excreted. The liver is exposed to toxicants that enter the body from ingestion and from absorption into the blood. Some chemicals are known to cause a variety of types of liver damage, from liver cell death to chronic liver damage to cancer.

Kidney toxin: Kidneys (like the liver) are vulnerable to chemical exposures because they process a high amount of the chemicals circulating in the body.

Mutagen: A mutagen is a substance which changes genes which are subsections of the DNA of cells. These mutations can be passed along as cells reproduce, sometimes leading to defective cells or cancer.

Neurotoxin: A substance which adversely effects the central nervous system or the peripheral nervous system resulting from exposure to chemical substances. These can include a wide range of effects from impairment of learning, memory, judgement and other mental functions, to fatigue, irritability and other behavioural changes. Effects can be short term or permanent. Peripheral nervous system damage can cause weakness in lower limbs, prickling or tingling in limbs, and loss of co-ordination. Personal care and household cleaning products are rarely tested for neurotoxic effects.

Quaternary Ammonium Compounds (Quats): Listed on labels as benzalkonium chloride, cetrimonium bromide, quaternium-15 and quaternium 1-29, these compounds are caustic and can irritate the eyes. Quaternium-15 is a formaldehyde releaser and the number one cause of preservative-related contact dermatitis. There is concern about their potential as sensitizers. For about 5% of people, quats are an extreme sensitizer and can cause a variety of asthma-like symptoms, even respiratory arrest. When they are used with hot running water, steam increases the inhalation of vapours. These compounds are used in a wide range of cleaning products and disinfectants as germicides, preservatives and surfactants.

Reproductive toxin: A substance which has adverse effects on the male or female reproductive system. This may include early puberty, decreases in fertility or miscarriages. Developmental toxicity is a sub-category of reproductive toxicity. Reproductive toxicity is a relatively new field of study which is of growing concern. Very few chemicals have yet been tested for reproductive or developmental effects. A chemical may be categorized as a known or suspected reproductive toxin, depending on the amount and types of studies done.

Respiratory toxin: A substance which has an adverse effect on the functioning or structure of the respiratory system. Respiratory toxicants can produce a variety of acute and chronic effects, from local irritation and bronchitis to lung damage resulting in emphysema or cancer. Asthma and respiratory infections are other possible effects of exposure to respiratory toxins.

Sensitizer: A sensitizer is a substance which may, after repeated exposure, trigger severe allergic-type reactions to even a small amount of the substance. Some doctors now believe that some substances may also trigger sensitization to a wide number of substances, the condition known as multiple chemical sensitivity (MCS). Organochloride pesticides and formaldehyde are two substances suspected of triggering MCS.

Skin toxicant: A substance which can result in short term or chronic skin irritation or damage. Contact dermatitis is the most common, but other possible effects include photosensitization, chloracne and skin cancer.

Sense organ toxicant: The senses of smell, vision, taste and hearing may be injured by a variety of physical, chemical and biological agents. Airbourne chemicals can cause eye irritation and in some cases result in permanent harm to vision. Some substances can result in hearing loss.

Teratogen: is a substance which can cause malformations of an embryo or fetus. This is a type of reproductive toxin.

Sources:, Labour Environmental Alliance Society, Toxins and Cleaners brochure, Physical and Theoretical Chemisty Laboratory, Oxford University.

For more information on types of adverse health effects, go to and click on Health Effects. Scorecard also provides information on health effects of a variety of chemical substances; click on About the Chemicals. Scorecard is a site of the Environmental Defense Network.

Return to Menu

Websites about Hazardous Substances and their Health Effects

Environmental Defense Organization

US National Institute for Occupational Safety and Health

New Jersey Department of Health and Senior Services

National Library of Medicine

US National Safety Council, Environmental Health Center (EHC)

Vermont Safety Information Resources Inc (SIRI)

Vermont Safety Informaton Resources Inc (SIRI) - extensive list of links to sites with information from MSDS sheets and hazardous chemical information

Agency for Toxic substances and Disease Registry, Center for Disease Control, US Government

Another useful source of informaton is Environmental Health Perspectives [EHP], a peer reviewed journal published by the National Institute of Environmental Health Science. EHP is now an open access journal - all content is freely available to everyone online.

To use PubMed to find articles in EHP, follow the link below and use a search strategy that includes the journal name (Environmental Health Perspectives) AND the subject you are looking for. The [ta] following the journal title limits the search to articles within that journal, a process that has obvious limitations but that can be very helpful for journals that offer full access.

Return to Menu