Holland & Barrett workers fear their health could be at risk as more than 750 stores remain open around the UK.
The company, which specialises in alternative healthcare, has kept its shops open during the coronavirus crisis, but staff are campaigning for them to shut, arguing their health is at risk due to impossible social distancing measures.
An online petition, which has amassed more than 4,000 signatures, says the chain should shut its doors to help prevent the spread of the virus.
Workers say that by working on the frontline and supporting people with low immune systems, the business could inadvertently be contributing towards the spread of COVID-19.
"Holland and Barrett is currently being seen as an essential company because we sell food that caters for those with dietary requirements. However, these past couple of weeks has been very difficult for my fellow colleagues and I," one worker on the page explains.
"Being on the frontlines, dealing with customers day in and day out, increases the chances of the virus spreading rapidly. The company has not been providing us hand washes, anti-bacterial gels and other form of protection to reduce the chance of catching the virus. The stores need to be closed, so we not only keep ourselves safe but also the nation. All we want, is to be safe and be with our loved ones during this period of crisis."
The chain said staff and customer safety is of "paramount importance."
Workers have two major concerns. Firstly, they claim Holland & Barrett is not an essential store, like a supermarket or pharmacy and secondly, that branches are too compact for social-distancing.
A Holland & Barrett worker - who asked to remain anonymous for fear of losing their job - told the BBC : "Holland & Barrett is putting our lives in danger with the pursuit of profit over life.
"The general atmosphere is one of fear and stress with a lot of our workers and colleagues quite frightened to speak their minds."
They said: "We do not sell essentials and have people coming in to purchase flapjacks and sticks of liquorice, hardly an essential purchase."
In many of the shops, they said: "It is almost practically impossible to maintain social distancing, as the aisles are very short width and when we have to deal with customer queries, they do not respect the boundaries.
A Holland & Barrett spokesperson said the chain is considered an 'essential retailer' in the eyes of the law.
"This relates to the fact that 90% of what we sell is food, vitamins and food supplements, which many of our customers rely on to manage their dietary or underlying conditions," a spokesperson said.
Examples the company cited included pregnant women in need of folic acid supplementation and those caring for customers with compromised immune systems, who may need additional vitamins or support at this time.
Holland & Barrett said it has provided gloves, masks and hand sanitiser to all stores and has also installed shielding screens at the counter.
It said social distancing is being enforced "with clear guidance in store".
"We have limited the maximum number of customers allowed in the stores at any one time, dependent on store size, and tape has been installed marking out a two metre distance from the tills with clear signage throughout stores.
"We are bolstering our online capacity as quickly as possible so customers can order from home where possible, and have set also up a new customer phone line for those customers who cannot access our website for home delivery."
