The Centre for Covid-19 Situation Administration (CCSA) on Friday lifted the five-day quarantine requirement for people in close contact with Covid-19 cases.
CCSA spokesman Taweesilp Visanuyothin said high-risk contact people would instead be required to closely observe their own health for 10 days and have an antigen test if they have respiratory symptoms.
They could continue to work with other people while observing their own condition, he said.
"This is a relaxation of disease control," Dr Taweesilp said.
High-risk people are those who do not wear a face mask, stay close to or talk with a Covid-19 case within a two-metre range for longer than five minutes, are sneezed at by a Covid-19 case or remain in a poorly ventilated place with a Covid-19 case longer than 30 minutes.