1.1 Introduction to Chemicals
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than 200 substances in industrial settings are potentially ototoxic (ATA 2016). When
a chemical has an effect on the auditive system, it is said to be ototoxic. Among
these substances are solvents, the main ones being toluene, styrene, xylene, carbon
disulfide, and trichlorethylene; asphyxiant compounds including carbon monoxide
and hydrogen cyanide; metals including lead and mercury; and pesticides such as
organophosphates.
More than 159 million of organic and inorganic substances are present in the
scientific literature, according to Chemical Abstracts Service (CAS) and with an
increasing exponential rate of growth (Binetti et al. 2008; CAS 2020). More than
105 chemicals are registered and marketed in Europe, 10% of which are sold in
quantities of more than ten tonnes per year and 30% in quantities exceeding one
metric ton. It should be noted that the general term of product or compound covers
two sets: substances and preparations, terms referring, respectively, to ‘pure’ products
and mixtures of two or more substances.
1.2 Chemicals in General
Hazardous products are chemicals having dangerous properties potentially able to
cause injury, damage, or harm to people, facilities, or the environment. The use of
these products, which are ever more numerous in all industrial, artisanal, and agricultural sectors, exposes the most part of workers to risks of acute or chronic toxicity, by respiratory, cutaneous, or digestive means. Many of these products—solids,
dust, liquids, gases, vapors, or fumes—are corrosive, irritant, allergenic, asphyxiating, fibrogenic, carcinogenic, reprotoxic, etc., and sometimes in low doses and
reduced exposure times. Used alone or in mixtures, chemicals may present various
effects harmful to human health. A workplace can bring together different people
and activities (factories, workplaces, offices, hospitals, farms, etc.).
In an industrial process, production takes place in different stages and operations,
as the raw materials are transformed into finished products with the possible use of
chemicals. Some of these products that we use at work can enter our body and cause
damage. Damage to health is not always visible immediately and sometimes only
appears years later. This is the case, for example, with carcinogenic, mutagenic, or
reprotoxic substances (toxic for reproduction).
The diversity of occupational exposures and other factors involved in the development of cancers (food, tobacco, environment, genetic predisposition, etc.) is such
that it is often very difficult to prove the link between cancer and cause (professional
activity), especially since the disease often occurs years after exposure or even after
the cessation of professional activity. In many cases, linking cancer to professional
causes requires a careful retrieval of the history of exposures experienced by the
single worker. Studies have identified a number of occupational factors potentially
able to increase risks or promote cancer development (Kasbi-Benassouli et al. 2005).
They include asbestos, arsenic, benzene, chromium, vinyl chloride, nickel, aromatic
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than 200 substances in industrial settings are potentially ototoxic (ATA 2016). When
a chemical has an effect on the auditive system, it is said to be ototoxic. Among
these substances are solvents, the main ones being toluene, styrene, xylene, carbon
disulfide, and trichlorethylene; asphyxiant compounds including carbon monoxide
and hydrogen cyanide; metals including lead and mercury; and pesticides such as
organophosphates.
More than 159 million of organic and inorganic substances are present in the
scientific literature, according to Chemical Abstracts Service (CAS) and with an
increasing exponential rate of growth (Binetti et al. 2008; CAS 2020). More than
105 chemicals are registered and marketed in Europe, 10% of which are sold in
quantities of more than ten tonnes per year and 30% in quantities exceeding one
metric ton. It should be noted that the general term of product or compound covers
two sets: substances and preparations, terms referring, respectively, to ‘pure’ products
and mixtures of two or more substances.
1.2 Chemicals in General
Hazardous products are chemicals having dangerous properties potentially able to
cause injury, damage, or harm to people, facilities, or the environment. The use of
these products, which are ever more numerous in all industrial, artisanal, and agricultural sectors, exposes the most part of workers to risks of acute or chronic toxicity, by respiratory, cutaneous, or digestive means. Many of these products—solids,
dust, liquids, gases, vapors, or fumes—are corrosive, irritant, allergenic, asphyxiating, fibrogenic, carcinogenic, reprotoxic, etc., and sometimes in low doses and
reduced exposure times. Used alone or in mixtures, chemicals may present various
effects harmful to human health. A workplace can bring together different people
and activities (factories, workplaces, offices, hospitals, farms, etc.).
In an industrial process, production takes place in different stages and operations,
as the raw materials are transformed into finished products with the possible use of
chemicals. Some of these products that we use at work can enter our body and cause
damage. Damage to health is not always visible immediately and sometimes only
appears years later. This is the case, for example, with carcinogenic, mutagenic, or
reprotoxic substances (toxic for reproduction).
The diversity of occupational exposures and other factors involved in the development of cancers (food, tobacco, environment, genetic predisposition, etc.) is such
that it is often very difficult to prove the link between cancer and cause (professional
activity), especially since the disease often occurs years after exposure or even after
the cessation of professional activity. In many cases, linking cancer to professional
causes requires a careful retrieval of the history of exposures experienced by the
single worker. Studies have identified a number of occupational factors potentially
able to increase risks or promote cancer development (Kasbi-Benassouli et al. 2005).
They include asbestos, arsenic, benzene, chromium, vinyl chloride, nickel, aromatic