Image copyright Glastonbury Festival Image caption The stainless steel cups have been developed by Sheffield firm Glogg and manufactured by AP Smith in Birmingham

As the Glastonbury Festival announces revellers are to be provided with steel drinking cups, BBC News looks at some of the questions being asked about giving bacchanalian band-lovers metal beakers.

Will they be a good souvenir?

Image copyright PA

Yes - and no. According to Glastonbury organisers, it's the first time sustainable, recycled stainless steel pint cups have been used on such a major scale, so it's nice to be able to be one of the first people to get their mitts on one.

However, they don't have a logo or any other identifying "Glastonbury" mark, so you'd have to be happy in the knowledge that only you and fellow-revellers know the significance of the beaker.

Maybe in future years there will be an identifying stamp - and full-on collecting will be possible. If that's the case, having one of the first ones could be invaluable.

Do you have to use them?

Good news for people with metallaphobia - they're not compulsory. In fact, they're only available at 10 of the main bars - overall there are hundreds of food and drink stands.

Are they dangerous?

It depends what you plan to do with them. If you want to partake in the unpleasant age-old festival tradition of urinating into cups and hurling them at the band, you'll find that although strong, they're difficult to throw very far.

They don't have lids, and are an awkward and non-aerodynamic shape to throw, with the contents likely to leave the vessel well before reaching your intended target.

The real danger comes from full bottles with the top still on. A litre bottle of water weighs 1kg (about 2.25lb), and hurled at a head can pack a powerful punch. That's why so many venues insist on removing the plastic cap when selling bottles of liquid.

Baby-faced pop phenomenon Justin Bieber, sensitive northern warbler Morrissey, and ladies' boy Harry Styles have all faced missiles filled by micturating merrymakers.

Of course, for people stumbling back to their tents, treading on a discarded metal cup is more likely to lead to a sprained ankle than mashing a plastic or paper one.

But the £5 deposit might encourage people hang on to them.

Will it make my beer taste funny?

It shouldn't do. The cups are made from food grade stainless steel. According to beer appreciation group Beer Advocate, stainless steel is fine - after all, beer kegs are made from the same material.

The metals to avoid are copper - which can react with the brew, and pewter - which can affect the taste. Also, antique pewter goblets tend to contain lead, which is poisonous.

What about people with metal fillings?

Image copyright Science Photo Library

People with amalgam fillings should have no trouble with drinking from stainless steel cups, says the British Dental Association.

Will it help the British steel industry?

Image copyright PA

Not on its own - although it's a nice nod towards that. But Glastonbury organiser Michael Eavis has high hopes his idea will get the ball rolling.

"For me, the single most important thing was being able to source British stainless steel for the cups from the place where it was invented - Sheffield, and then to take it on to the home of manufacture - Birmingham," he says.

"If the jobs, skills and infrastructure [in British steel] are lost they won't be replaced. We've worked on this project over the last three years, which will hopefully encourage other UK businesses to think about how they can support our steel industry during these very challenging times."

Remember though, the Glastonbury cups are made from 80% recycled steel. One of the high-profile troubled steel works is at Port Talbot in south Wales, which produces slab, hot rolled, cold rolled and galvanised coil. Which is new steel.

What about the environment?

The festival's green initiatives and sustainability coordinator Lucy Smith says: "For us, using these cups is part of the reusable revolution. It's very similar to paying 5p for a carrier bag. We think people will take to it.

"The pints are made by APS in Birmingham, and it was a significant part of the project to have them made with British stainless steel."

Steelwork does produce pollutants - Tata Steel says particulate material, sulphur dioxide and oxides of nitrogen are emissions the company monitors.

But the production of plastic glasses also releases toxins including trichloroethane, acetone, methylene chloride and benzene.

Plus - plastics are very stable and therefore stay in the environment a long time after they are thrown away, especially if they are shielded from direct sunlight by being buried in landfills.