Introduction
Toxic fumes are gases
Toxic fumes are gases that are poisonous or dangerous to people. There are different levels of toxicity, meaning some fumes (gases) are more dangerous than others. For instance, carbon monoxide can be present in your house. It is a toxic fume that comes from car exhaust or furnaces. In very, very low concentrations, you may only show mild symptoms like a headache or even none if you come and go a lot. But in higher concentrations it will be lethal (deadly ) and kill you.
Toxic fumes generally come from factories or result from chemical processes like combustion. It is now widely accepted that cigarette smoke is toxic, as it causes cancer, and has been linked to lung and heart diseases. Generally, most toxic fumes are man-made.
Gases and vapours produced, under many circumstances, have harmful effects on workers exposed to them by inhalation, being absorbed through the skin, or swallowed. Many toxic substances are dangerous to health in concentrations as little as 1ppm (parts per million). Given that 10,000ppm is equivalent to 1% volume of any space, it can be seen that an extremely low concentration of some toxic gases can present a hazard to health.
Gaseous toxic substances are especially dangerous because they are often invisible and/or odorless. Their physical behavior is not always predictable: ambient temperature, pressure and ventilation patterns significantly influence the behavior of a gas leak. Hydrogen sulphide for example is particularly hazardous; although it has a very distinctive ‘bad egg’ odour at concentrations above 0.1ppm, exposure to concentrations of 50ppm or higher will lead to paralysis of the olfactory glands rendering the sense of smell inactive. This in turn may result in the assumption that the danger has cleared. Prolonged exposure to concentrations above 50ppm will result in paralysis and death.
Definitions for maximum exposure concentrations of toxic gases vary according to country. Limits are generally time-weighted as exposure effects are cumulative: the limits stipulate the maximum exposure during a normal working day.
Chemicals, fumes, dusts and fibers can under many circumstances have harmful effects to workers exposed to them by inhalation, being absorbed through the skin, or swallowed. Persons exposed to harmful substances may develop illnesses (for example; cancer) many years after the first exposure. Many toxic substances are dangerous to health in concentrations as little as 1ppm (parts per million). Given that 10,000ppm is equivalent to 1% volume of any space, it can be seen that an extremely low concentration of some toxic gases can present a hazard to health.
It’s worth noting that most flammable gas hazards can potentially occur when the concentration of gases exceed 10,000ppm (1%) volume in air or higher. Toxic gases typically need detecting in sub-100ppm (0.01%) volume levels to protect personnel.
These Guidelines serve to enable reader to understand the hazards that chemicals can pose, to identify such hazards and take the necessary measure to prevent or control such hazards. Our job is protecting your health.
