People are being urged to switch to reusable face coverings as it has emerged that more than 100 million disposable masks are binned in the UK every week.
Nearly 70% of those who wear disposable masks are unaware they are single-use plastic, research for the North London Waste Authority (NLWA) found.
And around one in five wrongly believes disposable masks should go in the recycling.
In a bid to tackle the waste emergency, NLWA has launched a new campaign to encourage the nation to switch to reusable face coverings.
It revealed that 102 million single-use face masks are thrown away every week - enough to cover the pitch at Wembley Stadium 232 times over.
NLWA chair, Cllr Clyde Loakes, said: "The progress we've all made in reducing our reliance on single-use plastics is at risk of being undone during the pandemic, and disposable facemasks are a major culprit.
"They are not made of paper, they are not recyclable and whether they are binned or littered they will damage the environment."
Face mask littering has become a common sight during the COVID-19 pandemic, with 45% of those surveyed feeling angry when they see masks littered on the ground.
Many masks go uncollected, with 15% saying they would be inclined to pick up other people's litter but are refraining from doing so in case of contamination of the virus.
Steve Oulds, national commercial manager at Biffa Waste Services Ltd, said: "Contamination is one of the biggest challenges we face, and we are now seeing many disposable face masks coming through our facility every day."
He said the materials recovery facility is also dealing with more tissues and wipes than normal, and even COVID-19 test kits.
"None of these items are recyclable and they should go in the general waste bin," he said.
It is not just face masks that are fuelling the single-use plastic problem, as 16% of respondents admitted their use of other single-use plastics has gone up during the pandemic.
Delivery packaging was the top item to have increased in use (15%), followed by takeaway packaging (12%) and supermarket food packaging (12%).
However, more than one in five said while they are concerned about plastic pollution, health is currently more important and they are happy to continue using single-use plastic for now.