1.7 Chemicals in the Workplace
17
(7) The presence in particular products (pesticides, soaps, food additives, solvents)
(8) Individual sensitivity (especially to allergens, and this aspect is particularly
relevant to food and beverage-related industries
(9) Action mechanisms (stimulant and inhibitor compounds).
The classification of the toxic substance should be considered from several viewpoints. It often depends on the field of application, the objective pursued by an
organization, and/or even the anthropic activity itself.
1.8 Toxicity of the Chemical
Toxicology is the study of adverse effects of chemical substances on living organisms
(Hellman 2003; Stellman 1998). The toxicity of a foreign chemical (xenobiotic) to
the organism is a biological characteristic that depends on the atomic or molecular
structure of the compound and therefore its interaction with living matter. It is a
measure of the poisoning capacity of a chemical.
This toxicity also depends on the dose of xenobiotic needed to produce a measurable effect. In industrial environments, the toxic effect depends on the composition of
the air, the nature and physicochemical properties of the suspect substance, its conditions of use, and the individual himself. Industrial toxicology aims to determine a
threshold of safety requiring detailed studies to identify changes and alterations of
all kinds.
The main basis for the classification of chemicals is the assessment of exposure
levels with the impact on the environment (water, air, and soil). About 50% of the
international systems contain criteria relating to the volume of production of a chemical or the effects of pollutant releases. The most widely used criteria are mean ‘lethal
dose 50’ (LD 50 ) and mean ‘lethal concentration’ (LC 50 ) values. These data are evaluated in laboratory animals according to three main routes of administration—oral,
dermal, and inhalation options—for a single exposure. LD 50 and LC 50 are evaluated in the same animal species and using the same exposure routes (Hellman 2003;
Stellman 1998).
Toxicologists often test animals to determine whether small or large doses of a
specific chemical cause toxicity. One of these tests measures the chemical dose (LD 50 )
required to cause death in 50% of the animals. The greater the harmful effects of
a xenobiotic, or the lower the threshold dose of this compound, the more toxic this
compound is.
Depending on exposure conditions, most chemicals can cause both acute and
chronic toxicities. Harmful effects of both kinds of toxicity are often very different.
Toxicity is a measure of intoxication capacity and is an invariable characteristic of a
chemical (Hellman 2003; Stellman 1998). Basically, the intoxication can be:
(1) Accidental, which most often consists of the absorption of a single massive
dose, leading to immediate health effects such as irritation, burns, respiratory
or ocular disorders
17
(7) The presence in particular products (pesticides, soaps, food additives, solvents)
(8) Individual sensitivity (especially to allergens, and this aspect is particularly
relevant to food and beverage-related industries
(9) Action mechanisms (stimulant and inhibitor compounds).
The classification of the toxic substance should be considered from several viewpoints. It often depends on the field of application, the objective pursued by an
organization, and/or even the anthropic activity itself.
1.8 Toxicity of the Chemical
Toxicology is the study of adverse effects of chemical substances on living organisms
(Hellman 2003; Stellman 1998). The toxicity of a foreign chemical (xenobiotic) to
the organism is a biological characteristic that depends on the atomic or molecular
structure of the compound and therefore its interaction with living matter. It is a
measure of the poisoning capacity of a chemical.
This toxicity also depends on the dose of xenobiotic needed to produce a measurable effect. In industrial environments, the toxic effect depends on the composition of
the air, the nature and physicochemical properties of the suspect substance, its conditions of use, and the individual himself. Industrial toxicology aims to determine a
threshold of safety requiring detailed studies to identify changes and alterations of
all kinds.
The main basis for the classification of chemicals is the assessment of exposure
levels with the impact on the environment (water, air, and soil). About 50% of the
international systems contain criteria relating to the volume of production of a chemical or the effects of pollutant releases. The most widely used criteria are mean ‘lethal
dose 50’ (LD 50 ) and mean ‘lethal concentration’ (LC 50 ) values. These data are evaluated in laboratory animals according to three main routes of administration—oral,
dermal, and inhalation options—for a single exposure. LD 50 and LC 50 are evaluated in the same animal species and using the same exposure routes (Hellman 2003;
Stellman 1998).
Toxicologists often test animals to determine whether small or large doses of a
specific chemical cause toxicity. One of these tests measures the chemical dose (LD 50 )
required to cause death in 50% of the animals. The greater the harmful effects of
a xenobiotic, or the lower the threshold dose of this compound, the more toxic this
compound is.
Depending on exposure conditions, most chemicals can cause both acute and
chronic toxicities. Harmful effects of both kinds of toxicity are often very different.
Toxicity is a measure of intoxication capacity and is an invariable characteristic of a
chemical (Hellman 2003; Stellman 1998). Basically, the intoxication can be:
(1) Accidental, which most often consists of the absorption of a single massive
dose, leading to immediate health effects such as irritation, burns, respiratory
or ocular disorders