Agency chief Padungsak Thephasdin na Ayutthaya said the department had inspected safety measures at 19,820 workplaces and found that the vast majority - 86 per cent - observed the labour safety laws.

Of the 2,657 law-breaking workplaces, the top five sectors at fault were the mining industry, at 30 per cent of the sites inspected; consumer goods production (22 per cent); the construction industry (19 per cent); transport and logistics (13 per cent); and electricity, gas and waterworks (10 per cent).

The department also inspected 44,358 establishments with a total of two million employees to check on their compliance with regulations concerning workers' rights. This was out of 375,705 workplaces registered with the Social Security Office and with a combined 8.5 million workers, Padungsak said.

These inspections - focusing on small business establishments with less than 10 workers - found that 82 per cent followed labour laws. Workplaces with one to four employees frequently breached the laws.

Of the 7,887 small establishments at fault, the most common offence (47 per cent of companies inspected) - out of 38,598 law-breaking actions found - was failing to inform employees about their entitlement to holidays and breaks, and about working hours.

The Labour Protection Act 1998 stipulates that employers must put on the workplace notice board the working regulations - including holidays - in order to keep staff properly informed of their rights. Copies of the regulations must be sent to the Labour Protection and Welfare Department.

The other top four law-breaking actions involved labour payments, at about 24 per cent of companies inspected; holidays (10 per cent); overtime, working conditions and payments (5 per cent); and the minimum wage (about 5 per cent).