page_title: Asphalt
section_title: Health and safety
hierarchical_section_title: Asphalt / Health and safety
caption_attribution_description: English: Asphalt plant for hot mix in Ivanovec, Medjimurje County, Croatia - northeast viewHrvatski: Asfaltna baza u Ivanovcu, Međimurska županija, Hrvatska - pogled sa sjeveroistočne strane
context_page_description: Asphalt, also known as bitumen, is a sticky, black, highly viscous liquid or semi-solid form of petroleum. It may be found in natural deposits or may be a refined product, and is classed as a pitch. Before the 20th century, the term asphaltum was also used. The word is derived from the Ancient Greek ἄσφαλτος ásphaltos. The Pitch Lake is the largest natural deposit of asphalt in the world, estimated to contain 10 million tons. It is located in La Brea in southwest Trinidad, within the Siparia Regional Corporation.
  The primary use of asphalt is in road construction, where it is used as the glue or binder mixed with aggregate particles to create asphalt concrete. Its other main uses are for bituminous waterproofing products, including production of roofing felt and for sealing flat roofs.
  In material sciences and engineering, the terms "asphalt" and "bitumen" are often used interchangeably to mean both natural and manufactured forms of the substance, although there is regional variation as to which term is most common. Worldwide, geologists tend to favor the term "bitumen" for the naturally occurring material.
context_section_description: People can be exposed to asphalt in the workplace by breathing in fumes or skin absorption. The National Institute for Occupational Safety and Health (NIOSH) has set a recommended exposure limit of 5 mg/m³ over a 15-minute period.
  Asphalt is basically an inert material that must be heated or diluted to a point where it becomes workable for the production of materials for paving, roofing, and other applications. In examining the potential health hazards associated with asphalt, the International Agency for Research on Cancer (IARC) determined that it is the application parameters, predominantly temperature, that affect occupational exposure and the potential bioavailable carcinogenic hazard/risk of the asphalt emissions. In particular, temperatures greater than 199 °C (390 °F), were shown to produce a greater exposure risk than when asphalt was heated to lower temperatures, such as those typically used in asphalt pavement mix production and placement. IARC has classified paving asphalt fumes as a Class 2B possible carcinogen, indicating inadequate evidence of carcinogenicity in humans.
  In India Asphalt known as shilajit found in the Himalayas is consumed by people and is considered to have medicinal properties according to Ayurveda.
caption: An asphalt mixing plant for hot aggregate
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