Pressure is building on Amazon and other delivery firms to improve protection for workers worried about getting infected with coronavirus.
Some workers at US food delivery firm Instacart and US and Italian workers at Amazon have walked out, complaining of inadequate protection.
US senators have also written to Amazon boss Jeff Bezos to express concerns.
The companies have said they are taking extra precautions, amid booming demand for delivery services due to the virus.
“We are going to great lengths to keep the buildings extremely clean and help employees practice important precautions such as social distancing and other measures”, an Amazon spokesman said in a statement.
“Those who don’t want to work are welcome to use paid and unpaid time off options and we support them in doing so”.
Amazon said it had adjusted its practices, including increased cleaning of its facilities and introducing staggered shift and break times.
In Italy, the company said it had reduced deliveries since 22 March. However, union leaders say workers need access to better protection.
“Several employees working at the site use face masks for days instead of having new ones each day,” one union representative told Reuters.
A group of workers at Whole Foods, which is owned by Amazon, plan to walk out on Tuesday, citing similar problems.
The company told NBC it has “taken extensive measures to keep people safe.”
Last year, the company faced criticism for cutting healthcare benefits for 1,900 part-time employees.
Earlier this month, Mr Bezos – who is one of the world’s richest people with an estimated $115.6bn fortune – addressed the worries in an open letter to staff, thanking them for their work.
The company, which is looking to hire 100,000 more warehouse workers in the US to help address the surge in orders, has also said it would boost pay for warehouse staff around the world, including by $2 per hour in the US and by £2 per hour in the UK, where staff have been told to work overtime.
However, US lawmakers have questioned Amazon over reports of shortages of protective and cleaning supplies, as well as its sick leave policies.
The firm earlier faced strikes by workers in France and Italy and has been hit by legal complaints over the issues in Spain, according to a global alliance of unions coordinated by UNI Global Union.
