PRIO criteria for phase-out substances and priority risk-reduction substances

CMR substances are known or presumed to be carcinogenic, germ cell mutagenic, or toxic to reproduction. The properties of CMRs are so adverse that humans should not be exposed to these substances. It is assumed that even a single exposure of a very small amount of a CMR substance may cause permanent damage.

A carcinogenic substance is a substance that may cause damage in cells and tissues, which in the long term may turn into cancer. A germ cell mutagenic substance is a substance that may cause heritable mutations, i.e. changes in the genome, in germ cells. A substance that is toxic to reproduction may damage the sexual function, the ability to have children and/or the development of the embryo, foetus or child.

Fluorinated greenhouse gases (F-gases) are a group of gases most often used to replace substances that can deplete the ozone layer. They do not destroy the ozone layer but are very powerful greenhouse gases and, being thousands of times more powerful than carbon dioxide, they contribute to global warming. The fluorinated greenhouse gases include fluorocarbons (HFCs), perfluorocarbons (PFCs) and sulfur hexafluoride (SF6).

Read more about the substance group Chlorofluorocarbons (CFCs) and Hydrogen fluorocarbons (HFCs).

Endocrine disruptors are substances that are foreign to the body and may disrupt the body's own hormonal system. Many important processes in the body are regulated by hormones acting at very low levels in the body. These substances can, for example, contribute to impact on metabolism and the ability to have children, or contribute to the development of hormone-dependent cancers such as breast cancer.

The most critical stage for effects is the fetal stage. If a fetus is exposed to a hormone-disrupting substance, it can, for example, have effects on brain development or cause an increased risk of diseases in adulthood. In adults, the mechanism for regulating hormone levels in the body are more developed compared to fetuses and young children. This increases the risk for an endocrine disruptor to have irreversible effects on these more sensitive groups. During development, hormones control how cells mature and how they migrate to the right location. If this process is disturbed, it can cause permanent disturbances.

Sensitisers are substances that can activate the immune system and cause sensitisation. Once individuals are sensitised, they can have severe allergic reactions to further exposure, even if the doses are very low. Respiratory sensitiser means a substance that will lead to hypersensitivity of the airways following inhalation of the substance. Skin sensitiser means a substance that will lead to an allergic response following skin contact.

Respiratory sensitisers may induce asthma. Asthma is a severe adverse health effect and individuals should not be exposed to such substances. Very low doses of skin sensitising substances in Category 1A can cause severe allergic skin reactions. Exposure to these substances should therefore be avoided.

Note that mixtures containing one or more respiratory sensitisers, e.g., allergenic enzymes in cleaning agents, are not necessarily classified as allergenic. The generic concentration limit according to the CLP regulation for classification of mixtures in solution or granular form containing respiratory sensitisers is 1%, which is higher than for other hazard properties of phase-out substances in PRIO (normally 0.1% alternatively 0.3%).

The classification H420 according to CLP Regulation means that the substance is "Damaging to public health and the environment by destroying ozone in the upper part of the atmosphere".

In the stratosphere, sunlight constantly converts some of the oxygen molecules in the air into ozone. This ozone layer filters out harmful UV radiation from the sun. UV radiation can cause very hazardous effects to public health and the environment, as well as damage to technical material. The thinning of the ozone layer comes from emissions of ozone depleting substances such as CFCs (chlorofluorocarbons), HCFCs (chlorofluorocarbons), halons, chlorinated solvents, methyl bromide and similar substances. It is the chlorine or bromine content of these substances that depletes ozone in the stratosphere. The use of ozone depleting substances must be phased out in accordance with the Swedish environmental quality objective A Protective Ozone Layer. External link, opens in new window.

PBT/vPvB substances are persistent (poorly degradable), bioaccumulative (accumulate in living organisms) and toxic, alternatively very persistent and very bioaccumulative. If a substance or its transformation products is poorly degradable, it will remain in the environment for a long time.

The underlying assumption is that organic substances that are poorly degradable, can be taken up and enriched in living organisms and have toxic properties, always constitute a possible risk to human health and the environment. Persistent compounds, even though no toxicity have been shown in various tests, can with time lead to unpredictable adverse effects.

For substances that are both very poorly degradable and very bioaccumulative, it is even more difficult to assess the risks. The uncertainty in predicting future adverse effects is so great that even if it has not been proven in tests, some adverse effects is always assumed.

Cadmium

Cadmium remains in the body for a long time and accumulates particularly in the kidneys. When exposed for a longer period of time, the function of the kidney is damaged. Cadmium can also cause cancer, gene mutations and effects on bone density. The adverse effects arise already at low exposure levels. Cadmium is also hazardous to the environment with both acute and chronic effects.

Mercury

Mercury and its compounds (principally methylmercury) have adverse effects particularly on the nervous system and its development. They also has adverse effects on the cardiovascular system, immune system, reproductive system and kidneys. Disturbance to the development of the nervous system and toxicity to the central nervous system are the most sensitive and best documented effects. Mercury is transferred to the foetus, crosses the blood-brain barrier and probably inhibits brain development even at low concentrations. Children exposed to low concentrations of methylmercury for a long time may exhibit learning difficulties and impaired intellectual capacity.

Mercury is transformed to methylmercury by natural processes in the environment and is bioaccumulated in the food chain.

Lead

Lead and its compounds have adverse effects particularly on the nervous system and can give rise to impaired cognitive development and intellectual performance, foetuses and small children being particularly sensitive. Lead can be transferred from the placenta to the foetus and to breastfeeding babies through breast milk and can affect the development of the brain at low exposure levels. Lead can also affect the ability to have children. Other effects are high blood pressure and increased incidence of cardiovascular diseases in adults. International Agency for Research on Cancer (IARC) has classified lead as presumed carcinogenic.

PFAS (Per- and polyfluoroalkyl substances) are a group of organic substances that are extremely persistent (poorly degradable), by themselves or as degradation products. This means that they will remain in the environment for a very long time. All PFAS found in the environment are man-made since PFAS are not naturally occurrent in the environment. Some of them are bioaccumulative, i.e. they enrich in living organisms. Some of them are mobile, which means they can be widely distributed throughout the environment. For a few PFASs, such as PFOS and PFOA, there is evidence that they are harmful to human health but for most PFAS, there is still a lack of knowledge when it comes to their effects on health. However, there is reason to suspect that all PFASs may be harmful to human health.

Learn more about PFAS.

Skin sensitising substances can activate the immune system and cause sensitisation after repetitive skin contact. Once individuals are sensitised, they can have allergic skin reactions to further exposure. For substances in category 1 or 1B, higher doses are required for an allergic skin reaction to occur, or the allergic reaction is not as severe when compared to skin sensitising substances in category 1A.

Carcinogenic substances in Category 2 may cause cancer, however, the evidence for these effects is not as strong as for carcinogenic substances in Category 1A and 1B. Substances that are carcinogenic in Category 2 are considered suspected human carcinogens.

This refers to substances classified as Hazardous to the aquatic environment, Category chronic 1 (H410) or Hazardous to the aquatic environment, Category chronic 4 (H413) according to the CLP Regulation. The reason for choosing these two classification criteria is the ability of these substances to cause long-term negative effects. This approach is in accordance with the intentions of “A Non-Toxic Environment” to reduce exposure of substances with long lasting effects.

A substance classified as H410 is very toxic to aquatic life with long lasting effects.

Classification with hazard statement code H413 is a kind of safety net classification where, in absence of chronic toxicity data, the hazard for long term effects is suspected to be similar as for substances classified with H410. Hazard code H413 is used for substances which may bioaccumulate (BCF≥500 or log Kow≥4), are not rapidly degradable, have low water solubility (<1mg/l) but no acute toxicity is expressed in toxicity tests performed at the solubility limit. Another example of when classification with the hazard statement H413 is relevant is for toxic metals for which there is no information available on transformation/dissolution.

Substances with hazard statement code H411 and H412 (according to CLP-Regulation), do not meet this PRIO criterion as these substances have a known lower chronic toxicity than H410.

Mutagenic substances in Category 2 may cause genetic defects in human germ cells, however, the evidence for these effects is not as strong as for germ cell mutagens in category 1A and 1B. Mutagenic substances in Category 2 are therefore considered having the potential to induce heritable mutations in the genetic material of humans. Mutagenic properties may lead to heritable mutations or damage that in the long term may lead to cancer or defects on reproduction. It is assumed that even a single exposure of a very small amount of a mutagenic substance may cause damage. The evidence for mutagenic substances in Category 2 is normally based on mutagenic effects in somatic cells (not germ cells) of mammals in experimental studies.

Substances that produce high acute toxicity are substances that at single low exposure concentrations can cause mortality and/or specific, target organ toxicity, both reversible and irreversible, immediate and/or delayed. Specific target organ toxicity can occur by any route that is relevant for humans, i.e. principally oral, dermal or inhalation. The adverse effects include toxicologically significant changes which have affected the function or morphology of a tissue, organ or organ system, sometimes fatal.

Potential PBT/vPvB substances are suspected of having persistent (poorly degradable), bioaccumulative (accumulate in living organisms) and toxic, alternatively very persistent and very bioaccumulative properties. See description of properties for PBT/vPvB substances. Potential PBT/vPvB substances in PRIO meet the screening criteria for a PBT assessment within Reach.

Substances concluded to meet the criteria for PBT/vPvB by the PBT expert group will normally be added to the Candidate List in REACH (for PBT and/or vPvB) and may in some cases also be proposed for inclusion in the Stockholm Convention. The operator should consider whether a potential PBT/ vPvB substance should be treated as a phase-out substance.

Substances that are toxic to reproduction in Category 2 can cause adverse effects on sexual function and fertility, and on development of the embryo, foetus or child in humans. However, the evidence for these effects is not as strong as in Category 1A and 1B. Substances that are toxic to reproduction in Category 2 are considered as suspected human reproductive toxicants.

Substances that cause effects on or via lactation are allocated to a separate subcategory. The property hazardous to breastfed babies should be indicated when substances are absorbed by women and have been shown to interfere with lactation, or which may be present in breast milk in amounts sufficient to cause concern for the health of a breastfed child.

Substances that produce target organ toxicity after repeated or long-term exposure are substances that at low exposure concentrations can cause specific, target organ toxicity, both reversible and irreversible, immediate and/or delayed. Specific target organ toxicity can occur by any route that is relevant for humans, i.e. principally oral, dermal or inhalation. The adverse effects include toxicologically significant changes which have affected the function or morphology of a tissue, organ or organ system, sometimes fatal.