A plastic washing-up bottle that is at least 47 years old has been found washed up on a beach in the UK with its lettering and messaging still clear, prompting warnings about the enduring problem of plastic waste.

The item, found by a coastguard warden at a beach in Somerset, “still looks almost new”, said the organisation. “We were staggered yesterday by how much debris has washed up on the beach,” wrote the Burnham Coastguard on Facebook. “It’s shocking how long … rubbish can survive and ultimately harm nature.”

The bottle advertises itself as 4d off, meaning it dates back to before decimalisation was introduced in Britain in 1971, making it at least 47 years old.

The item – spotted among seaweed at Brean beach near Burnham-on-Sea – was a Fairy Liquid bottle, whose advertising slogan decades ago touted its mild and gentle properties, particularly for your hands.

Some types of plastic bottles take 450 years to break down. The UK produces more than 170m tonnes of waste a year, much of it food packaging, and only a third of plastic packaging is recycled.

Plastic waste is so ubiquitous that microplastics and fibres, some smaller than the width of a human hair, have been found in shellfish, tap water, honey, sugar and table salt. Very little is yet known about the health impact of these microplastics, which are ingested by humans and animals.

Burnham coastguard urged people to reduce plastic use and making sure they disposed of rubbish in bins, especially when at the beach. They also encouraged people to be careful with what they flushed down the toilet, saying “cotton buds are the worst offenders” and to join a local beach clean-up group.