The most common toxic chemical groups

Chemical advisers, toxicologist, epidemiologists, governmental and local inspectors… the toxic chemicals issue engages a long list of professionals attempting to define and control the toxic threat. It can seem like a jungle out there – so many chemicals in use, and such a lack of knowledge. Most companies neither have the staff resources nor the time to dig into the details. However, it’s worthwhile getting acquainted with some basics. There is a limited number of toxic “hot spots” that are under scrutiny. Screening through this shortlist will make you better equipped to understand where your toxic footprint might be.

– Plastics

Plastics are a wide group of materials based on polymers. Commonly used polymers are polyethylene (PE), polypropylene (PP), polyvinylchloride (PVC), polystyrene (PS) and polyurethane (PU or PUR). However, the list of polymers is much longer, and new inventions are constantly being added. Mixing different polymers (to co-polymers or multilayer solutions) is also common to improve the functionally of plastic materials. The choice of polymer depends on desired function.

Almost all polymers are produced from fossil material. Biobased polymers, such as PLA made from agricultural feedstock, are increasingly being used although they still have a very marginal market share. Most plastic materials contain numerous additives (functionality chemicals) to enhance performance. The amount of additives applied can vary from 0-95 per cent depending on the polymer and product type . Many of the negative properties of plastics come from the additives rather than from the polymers themselves.


– Plasticisers

These are used to soften plastics. While some polymers are intrinsically “soft”, other polymers require substantial amounts of plasticisers to become flexible. PVC represents the dominant use of plasticisers.

Phthalates are one common group of plasticisers that are being used in large quantities, often around 30-60 per cent of the plastic’s total composition. Several phthalates have hazardous properties, such as being toxic to reproduction. Because phthalates are not chemically bound to the plastic material and can leach out, users are likely to be exposed to them.


– Flame retardants

Flame retardants are used to make a product less flammable. Depending on national regulations, flame retardants may be required in a product. Examples of such products are protective clothing, curtains and fabrics used in furniture, to name but a few. Some currently used flame retardants, especially halogenated compounds, have been shown to have hazardous properties and some are subject to international and/or national regulations.

Historically, brominated flame retardants (BFR) have been extensively used. BFRs have proved to be toxic, to bioaccumulate and to persist in the environment.


– Biocides & Pesticides

Biocides and pesticides are used to prevent living organisms from thriving on your goods. Biocides and pesticides can be used to prevent anything from bacterial growth to grazing by large animals. They are common ingredients in products that are sensitive to bacterial growth, either during shelf life or consumer use, or both. Biocides can also be used during manufacture and transportation and to give the end product antibacterial properties.

Since these chemicals are actually designed to kill, they are inherently risky to include in products. It is a great challenge to develop biocides and pesticides that will not harm other organisms, including humans.


– POPs

Persistent Organic Pollutants (POPs) are a group of chemicals that possess a particular combination of properties that make them extremely long-lasting and widespread in the environment. Since they are also toxic and bioaccumulate, they have received special attention from the international community. A global treaty, the Stockholm Convention, has been created to reduce and ultimately eliminate their use. Beginning with 12 chemicals in 2004 (called “The dirty dozen”) the convention has currently expanded to cover 24 substances/substance groups. Effects of POPs include cancer, allergies and hypersensitivity, damage to the nervous system, reproductive disorders and disruption of the immune system. As POPs degrade so slowly and are often transported over large distances, in practice it is impossible to clean them from environment.


– Heavy metals

Heavy metals is a wide group of elements, of which many have toxic properties, for example causing mental and physical disorders among humans and other mammals. Common examples are chromium, arsenic, cadmium, mercury and lead. Because of their extensive use in society, heavy metals are found in unhealthy levels in the environment. Even though the toxicity of heavy metals has been known for decades, lead and mercury are still widely used in all sorts of articles, from batteries to electronic equipment and toys.


– Hormone Disrupting Chemicals (EDCs)

Some chemicals act by interfering with the hormones in animals and plants. The hormone system is also called the endocrine system. Since hormones regulate everything from behaviour to organ development, reproduction and growth, messing with this system can have serious effects. Endocrine Disrupting chemicals (EDCs) work through numerous mechanisms, and have been shown to play a role in many public health issues such as obesity, autism and developmental disorders.


– CMRs

Chemicals known as “CMR”s, can cause (C)ancer, induce (M)utations to DNA, or harm our (R)eproductive system.

If a substance is identified as having one or more of these properties (there are standardized tests to check this) a number of obligations kick in for companies. For instance: requirements for warning labels signalizing the danger and making sure safety data information is available to those using the product.