The bill will apply to companies that employ staff in Portugal and is intended ot identify those whose premises and facilities contain asbestos, a carcinogen banned substance that was commonly used in construction in the past.

PEV plans to extend existing rules for state-owned buildings, such as schools or hospitals, to companies. A list of state buildings containing asbestos has already been drawn up and the asbestos removed from some of them.

The Government has decided that the removal of asbestos in public buildings should be completed by 2020, and the process involves more than 4,200 buildings across the country.

According to the PEV proposal, which was delivered to parliament in July, the Working Conditions Authority (ACT) along with workers' and employers' associations will drawn up a plan to identify all the companies whose buildings contain asbestos.

Workers at the companies whose buildings contain asbestos will be informed of the situation.

Asbestos only becomes hazardous if it starts to break up due to a lack of maintenance or when it is removed. Asbestos particles that are released into the air are a carcinogen once inhaled.

In addition to roofing, asbestos was used in floors, false ceilings and linings of building ducts.

Asbestos is a naturally occurring mineral fibre and before it was discovered to be a carcinogen was used in construction because of its insulation properties, strength and durability.

In 1999, a European Community directive banned the use of asbestos and this ban was backed up by Portuguese legislation in 2005.