The confirmation comes after unions raised concerns over healthcare staff being “pressured” into returning to work amid high rates of absences.
New guidelines were released on Friday which allow employers of staff in key national infrastructure, including health, transport and food supply, to apply for exemptions to self-isolation requirements for workers who are contacts of a positive Covid case.
The exemptions do not apply to contacts who are within the same household.
Several unions have raised concerns over staff being pressured into returning to work after being told to self isolate.
Mr Yousaf told BBC Good Morning Scotland on Monday: “I don’t dismiss any of the unions’ concerns. I met with a number of health and social care unions last week, and the RCN and Unison in particular have raised this issue.
“First of all this is only to be deployed in extremis, and secondly it is entirely voluntary.
“Therefore if any individual feels that they are at risk, that they don’t want to go ahead with the policy. They do not have to.
“I will be making it very clear. I’ll be writing to the chairs of health boards to stress that this is an entirely voluntary arrangement.”
The Royal College of Nursing union has warned staff are under “increasing pressure” as services are in such high demand.
Julie Lamberth, vhair of the RCN Scotland Board, said on Monday: “Although the Scottish Government’s self-isolation exemption rules are based on voluntary participation by health and care staff, there remains the potential for increasing pressure on staff to return to work to support hard pressed services.
"We have still not seen the evidence behind this position, including how many staff will be affected.
“We will continue to seek feedback from our members who will have to deal with this on a day-to-day basis about how the process is applied in practice.”
In Scotland, workers who would be exempt must be asymptomatic, in possession of a valid vaccination record, have evidence of a negative PCR test, and return a negative lateral flaw test for up to ten days after exposure, as well as comply with PPE requirements.
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