The Mayor of London will offer all vulnerable staff a personalised assessment to gauge their physical and mental health during the Covid-19 outbreak.
All Black, Asian and minority ethnic (BAME) workers will be eligible – along with older staff, and those with pre-existing health conditions.
Unions and charities have called on other employers to follow suit, as lockdown eases and more businesses gear up for a return to work.
Car showrooms and markets reopened in England on 1 June, with high street shops, department stores and shopping centres due to open in two weeks, on 15 June.
All businesses must carry out a risk-assessment with employees or trade unions involved before they call staff back to work.
But the Mayor has gone a step further – offering personalised support for the most vulnerable.
Eligible workers at City Hall, Transport for London (TfL), the Metropolitan Police and London Fire Brigade will all be offered risk assessments.
BAME employees have been included by default because Covid-19 has hit ethnic minority groups hardest.
Black men and women are twice as likely to die from the disease as their white peers, when other factors like age and poverty are accounted for, according to ONS data.
Mr Khan has pushed the Government to find out why – lobbying for figures on the racial demographics of Covid-19 hospital deaths, which are now being published.
He also wants ethnicity to be recorded on death certificates, and has called for an independent inquiry into why BAME people have been worse affected.
The Mayor warned that the pandemic must be “a wakeup call” for Britain.
“Far from being a great leveller, the coronavirus crisis has exposed the unacceptable major inequalities in our society,” he said.
“We owe it to every Londoner, regardless of background or ethnicity, to be able to live and work in safety.”
Business in the Community – a charity promoting social responsibility among employers – backed the Mayor’s plans for his workforce.
Race equality director Sandra Kerr praised Mr Khan for “leading the way as an responsible employer” to ensure the impact on BAME staff is minimised.
Trade union Unison also welcomed the Mayor’s approach, with regional secretary Maggie Ferncombe applauding “the leadership London needs”.
Coronavirus has merely highlighted existing inequality that BAME communities face in the capital, Ms Ferncombe said.
“Hopefully other London businesses will follow suit and go on to work with black, Asian and minority ethnic community groups and trade unions to address the underlying issues when this particular health crisis is over,” she added.
But the Mayor’s Office was unable to clarify what changes eligible employees can expect after their risk assessment.
Those with underlying health conditions are already working from home, masks are being provided to frontline transport staff, and workplaces are enforcing social distancing.
A spokesperson said different organisations under the Mayor’s authority have “differing needs and concerns”.
Support will go beyond the legal requirements “so that staff feel safe in this unsettling time”, he said.
“Managers across all of the organisations will be encouraged to speak to their own staff and work with senior leadership teams to make sure measures are in place to protect them,” he added.