Chemical name: Asbestos, crocidolite, Trimagnesium;disodium;dihydroxy(oxo)silane;iron(3+)

Final regulatory action has been taken for the category: Industrial

Final regulatory action: The chemical is Severely Restricted

Use or uses prohibited by the final regulatory action:

No person shall advertise, sell or import products, other than those listed below, that are composed of or contain crocidolite asbestos products.

Use or uses that remain allowed:

A person may import a product that is composed of crocidolite asbestos fibres if the following conditions are met:

the product is imported for the purpose of manufacturing diaphragms for chloralkali production or acid and temperature resistant seals, gaskets, gland packings or flexible couplings.

a written notice is given by the person with the information required in the Regulations on or before the date of importation of the product;

a statement is printed on the container of the product or a label affixed to the container that indicates in English and French that the product contains crocidolite asbestos fibres;

A person may advertise, sell or import into Canada the following products containing crocidolite asbestos fibres:

"asbestos" cement pipes;

torque converters

diaphragms for chloralkali production: or

acid and temperature resistant seals, gaskets, gland packings or flexible couplings or any product composed of or containing one or more of those products if

the product is constructed in such a way that, upon reasonably foreseeable use, the crocidolite asbestos fibres will not be released into the ambient air; and

a statement is printed on the container of the product or a label affixed to the container that indicates in English and French that the product contains crocidolite asbestos fibres.

The final regulatory action was based on a risk or hazard evaluation: Yes

Summary of the final regulatory action:

The Hazardous Products Act (HPA) authorizes the prohibition and regulation of the sale, advertisement and importation of products that are likely to be a danger to the health or safety of the public. Part I of the HPA designates "prohibited products" which may not be sold or imported for sale into Canada. The specific "asbestos"^{1 products that as "prohibited products" under the HPA are:}

^{Textile fibre "asbestos" desinged to be worn by a person, other than those for protection against fire or heat hazards and are constructed in a way that ensures that "asbestos" fibres will not become separated from the product when used as intended (date issued July 17, 1973)}

^{Products containing "asbestos" which are used by children for learning or play in which "asbestos" may become separated from the products (date issued June 1, 1976)}

^{Products for use in modelling or sculpture (date issued June 1, 1976)}

^{Drywall joint cements, compounds or spackling or patching compounds made in such a way that airborne "asbestos" may become separated from the products during preparation, application, repair, or removal; (date issued April 24, 1980)}

^{"Asbestos" products used to simulate ashes or embers (date issued April 24, 1980)}

^{Products containing "asbestos" that are packaged as consumer products (date issued May 5, 1988)}

^{Spray applied "asbestos" products, except mixtures of "asbestos" fibres and bituminous or resinous based materials where the fibres are encapsulated with the binder during spraying and the resulting materials are not friable after drying (date issued August 24, 1989)}

^{The Hazardous products (Crocidolite Asbestos) Regulations under the HPA prescribe the labelling requirement and grealty restrict the conditions under which crocidolite asbestos and products containing crocidolite asbestos may be advertised, sold or imported into Canada, thereby limiting exposure to this type of asbestos by users of these items.}

^{1. Asbestos is defined as a "commercial term applied to a series of silicate minerals." There are two groups of "asbestos" minerals: the amphibole group (crocidolite, tremolite, actinolite, amosite and anthophyllite) and the serpentine group (chrysotile).}

The reasons for the final regulatory action were relevant to: Human health

Summary of known hazards and risks to human health:

When inhaled, the diseases associated with "asbestos" exposure are asbestosis, mesothelioma, carcinoma of the lung (commonly referred to as lung cancer), and other "asbestos" related cancers. Each of these diseases is characterized by a period of latency: that is, the existence of a time interval, usually of many years, between first exposure to "asbestos" and the clinical manifestation of the disease. The disease risk depends on the length and intensity of exposure, and on the fibre size and type.

Asbestosis is a chronic, restrictive lung disease due to the inhalation of "asbestos" fibres. It is characterized by diffuse interstitial fibrosis or scarring which produces a "small, tight lung". Typical pulmonary function changes include restriction of lung volume, diminished forced vital capacity, and a decrease in diffusion capacity.

Asbestosis has historically been associated with prolonged and heavy occupational exposure to "asbestos". The pulmonary fibrotic changes develop slowly over the years, are irreversible, and will normally progress even in the absence of further exposure to "asbestos". The disease can become seriously disabling. Asbestosis is, however, more often a cause of morbidity (illness) among "asbestos" workers than it is a cause of mortality. Still, those with asbestosis are susceptible to death from related causes - often infection or cardio-respiratory complications.

Mesothelioma is a rather rare cancer arising from the surface-lining cells of the pleura and the peritoneum. These surface-lining cells are called the mesothelium and hence the name of the disease, mesothelioma. Malignant mesothelioma is of two types, pleural and peritoneal, depending upon whether the site of the tumour is the lung or the abdomen. The tumours that appear are unusual and striking. They are generally diffuse, spreading rapidly and widely over the large surfaces of the thoracic or abdominal cavities.

Mesothelioma was for a time thought to be uniquely associated with "asbestos" exposure. On the basis of the available data, there is still little doubt that the great majority of reported cases of mesothelioma are attributable to "asbestos" exposure. While it is true that there is now a growing body of evidence which strongly suggests that mesothelioma can occur and indeed has occurred in the absence of any known or likely exposure to "asbestos", these cases are, comparatively, exceedingly rare.

Lung cancer, unlike asbestosis or mesothelioma, is not specifically associated with "asbestos" exposure. Moreover, it has had a particular history of association with cigarette smoking. Pathologically, there does not apprear to be any basic difference between pulmonary carcinoma in general and that associated with persons exposed to "asbestos", save that whereas the majority of tumours appear in the upper portion of the lungs, those in "asbestos"-exposed individuals appear more commonly (but not always) in the lower lobes. However, serious issues of causation have been raised when lung cancer develops in "asbestos" workers, especially in the absence of co-existing asbestosis. While most persons exposed to "asbestos" who develop lung cancer are smokers, it is now generally recognised that "asbestos" on its own in the absence of smoking is capable of inducing lung cancer and that the tumour may develop even where there is no co-existing asbestosis.

"Asbestos" exposure can also produce scarring, both localized and diffuse, of the lining of the pleural surfaces, giving rise to pleural thickening, benign pleural effusions, and pleural plaques. In general, these limited pleural changes and plaques are not associated with clinical and functional abnormalities. They are simply markers of "asbestos" exposure. However, once in a while this pleural process can become rather diffuse and can severely restrict lung function, thus incapacitating the individual. Pleural changes may or may not be accompanied by asbestosis.

Certain particles of "asbestos" fibres, once inhaled in the lungs, may become coated with a substance containing protein and iron to form "asbestos" bodies. Fibres other than "asbestos" can provide a core on which similar coatings can develop. "Asbestos" bodies are not themselves harmful, but represent a benign tissue reaction to "asbestos" fibres. Principally they serve as evidence to "asbestos" exposure, as do asbestos warts which are harmless skin growths that occur when "asbestos" fibres penetrate the skin.

The risks are greatest for workers in industries which produce and use "asbestos", such as mining and milling. In the past, workers in these environments were exposed to 100 - 1000 times more airborne "asbestos" fibres than today's workers. Today's strict standards limit workers' exposure and the ban of most uses of amphibole "asbestos" has reduced the above-mentioned risks.

Expected effect of the final regulatory action in relation to human health:

The Hazardous Products Act authorises the prohibition and regulation of the sale, advertisement and importation of product that are, or are likely to be, a danger to the health or safety of the public.

The Crocidolite Asbestos Regulations prescribe the labelling requirements and greatly restrict the conditions under which crocidolite asbestos and products containing crocidolite asbestos may be advertised, sold or imported into Canada, minimizing human exposure to crocidolite asbestos for workers and consumers.

Date of entry into force of the final regulatory action: 05/10/1992