bitumen is produced through the pyrolysis of plant products most of
them come from bituminous coal.
Bitumen contains large quantities—20 to 50%—of polyaromatic compounds, some of which have been shown to be carcinogenic in animal studies. Bitumens are classified as Category 2 carcinogens, meaning that they contain over 50 ppm of benzopyrene.
Its use in road and highway construction is declining every year.
The 30,000 metric tons of Bitumen produced annually in France are reserved for specific applications, such as oil-based solvent-resistant coating mixes and flux oils.
Asphalt has a very different chemical makeup.
Asphalts are complex mixtures of hydrocarbons with high molecular weights.
They constitute the heaviest fraction of crude oil and serve as a
base for finished products such as asphalt or coating mixes.
They are not classified as carcinogens.