At least 80,000 people have been affected by a massive fire that ravaged the Ming Dih Chemical Co factory complex in Samut Prakan on Monday.

The blaze was brought under control briefly on Tuesday only to reignite amid the charred ruins of the factory on Tuesday around 4pm.

Overall, firefighters took more than 24 hours to douse the fire that followed an explosion around 3am on Monday.

One rescue worker was killed and 40 others were injured including firefighters.

The provincial governor on Tuesday said that the damage from the fire spanned a large radius around the burned-out factory, causing damage to private property and affecting 80,916 people across Bang Phli district.

The explosion and the fire forced the evacuation of 1,992 residents living within a 5-km radius of the factory.

Some of those affected took refuge at one of eight emergency shelters.

Police said 183 people have so far filed complaints of damage against the company.

The Pollution Control Department needs to ensure the air quality within 3-5km from the factory is safe before residents in the areas are allowed to return home.

An initial inspection showed that the air quality within one kilometre of the site was harmful to health on Tuesday.

The factory was opened three decades ago, when there was no environmental impact assessment (EIA) regulation in place.

Meanwhile, Ming Dih Chemical Co has issued a statement expressing its regrets over the incident and pledged to offer compensation for all the damage that occurred.