Some foreign companies in Shanghai asked their employees to work from home on Monday when the city was shrouded in acrid smog, Oriental Morning Post reported on Tuesday.

The move, adopted by multinational consumer goods company Unilever and some other companies, drew admiration from those who had to leave their homes when the air quality index published by the US Consulate reached 442, or hazardous, at 7 am on Monday.

As early as Dec 6, Unilever said in a post on its micro-blogging service that the company advised its workers to avoid venturing out and to stay at home to deal with their jobs on Monday. It reminded its workers to regularly check their e-mails and the company's micro blog while working from home.

The decision was confirmed by the company's employees, who told the newspaper Unilever sent the notice to workers via other channels, such as e-mail and mobile messaging services.

Employees said they were not surprised by the decision as they have been allowed to work from home before in the event of disastrous weather conditions including typhoons and heavy rainstorms.

Another global sportswear company, which the newspaper didn't identify, also asked its employees to stay at home on Monday to "make its team members' safety a priority".