The US retail giant Amazon has been criticised by customers for increasing its use of plastic packaging.
While UK supermarkets and shops try to use less plastic, Amazon earlier this year introduced a new range of padded plastic envelopes for deliveries.
One fed-up customer told the BBC: "Amazon shouldn't be creating more plastic waste."
Amazon said its SmartPac envelopes are recyclable and that it is "working to improve" its packaging options".
"Over the past 10 years, our sustainable packaging initiatives have eliminated more than 244,000 tons of packaging materials, avoiding 500 million shipping boxes," an Amazon spokesperson said.
"SmartPac mailers are kerbside recyclable in some cities, and in all store drop-off locations."
Concern is growing about the amount of plastic waste that ends up in our oceans, harming marine life.
But Amazon said it urged customers to recycle its plastic envelopes, along with its Prime Now plastic bags.
If your local council doesn't take them through its normal kerbside pick-ups, you can see where you can recycle plastic bags locally at the Recycle Now website.
Alex, who works in higher education and did not want to share her surname, said Amazon "has a duty to act and set the standard for others".
"I haven't been buying from Amazon because of the way they treat their workers, and really this is the last straw," she told the BBC.
"Now that Greenpeace has found that microplastics and hazardous chemicals have reached Antarctica, this should be a stark warning to all of us that this is no time to be complacent."
Andy Taylor, a retail manager from Leighton Buzzard, also said that he was upset about Amazon using more plastic packaging. "I've had a few of these deliveries recently," he told the BBC.
"They almost seem to be completely blind to the shift to more ecologically sound practices generally by business."
Is there a sound reason for opting for plastic rather than paper envelopes? Not according to the Confederation of Paper Industries.
A spokesperson for the CPI said: "Not only is paper and cardboard a uniquely renewable, recyclable and re-usable resource, it's also strong and flexible enough to keep goods safe while in transit making it the perfect packaging material.
"Many supermarkets, shops on the high street and online retailers have been making the switch from plastic to cardboard for their packaging recently and it's a trend we would like to see continue."
Alex wants Amazon to rethink its plans. She said: "Even if the plastic is recyclable I am not confident that it all gets recycled, so where does it end up?
"Also Amazon's move places the onus on the customer. I don't believe creating plastic packaging and then expecting consumers to recycle it is the answer."