France, UK, Spain, Brazil, Australia, Canada and the US are taking part
Hairdressers, pet groomers and farmers worldwide are collecting hair and fur to help mop up the devastating oil spill in the Gulf of Mexico.
The hair, stuffed into nylon tights, helps booms soak up thick oil spewing from the blown-out well off Louisiana.
About 370,000 salons are taking part, said the charity organising the massive "hair lift". Matter of Trust is largely co-ordinating its efforts via Facebook.
Some 450,000lbs (204,000kg) of hair and fur is said to be arriving each day.
Hair is an extremely efficient material for taking in all kinds of oils including petroleum, Matter of Trust's co-founder Lisa Gautier told the BBC's World Today programme.
She explained that each follicle has an enormous surface area, which the oil "sticks" to.
Volunteers have been stuffing the nylons with hair at 15 warehouses close to the disaster zone, making huge "hairy sausages" or booms, she said.
The booms will be laid on beaches rather than out at sea, soaking up any oil that washes ashore.
The technique has been backed by the Applied Fabric Technologies, the world's second largest oil boom manufacturer.
Ms Gautier said donations had come from France, England, Spain, Brazil, Australia, Canada and the US, and that new volunteers were signing up all the time. There are constant updates on shipments on the charity's Facebook page.
Alpaca and sheep farmers have also got involved, according to the San Francisco-based charity.
Oil has been escaping at a rate of 5,000 barrels (210,000 gallons) a day since 20 April, after an explosion on a BP-leased rig.