With May Day approaching, there is not a quiet moment at the Vaasa-based masquerade store, Narniaan (Destination Narnia), as buyers of all ages hunt for the perfect balloon.

The owner of the store, Heli Kahlos, has prepared for the rush by asking her parents to pitch in. She has also ordered an extra tank of helium.

"Let's hope it's enough for everyone to get their favorite balloon," Kahlos says.

The shop’s selection includes traditional animal characters, as well as Moomin, Frozen and My Little Pony balloons.

However, each year has its own trends. Where a few years ago rainbow-striped poop balloons where the ultimate must-haves, this year’s inflated poop is pink or traditionally brown.

Metre-tall unicorn sold out

The traditional helium-filled May Day balloon has been replaced by more exciting shapes. One of the most highly coveted balloons at Narniaan, this year, has been a unicorn that measures almost a metre in height.

At the shop the unicorn already sold out in pre-sales—even the importer is out of unicorn balloons.

On Thursday, a motley crew of pre-inflated balloon characters awaited their lucky owners in the back of the store.

Kahlos muses that when it comes to balloons, "flashiness is important. I suppose that’s why these are so popular."

Kids flexible, adults particular

A May Day balloon is not just a thrill for young children. Adults—university students in particular—buy sparkling wine bottle- or wine glass-shaped ones. And, of course, those pink poop balloons.

"Some also buy characters from their childhood, like Super Mario or Piglet," Kahlos explained.

Buyers’ budgets vary. Some splurge on their May Day celebrations, some purchase just one balloon. The size of the balloon matters: A small balloon might go for five euros, but a showier balloon can cost up to 20 euros.

Kahlos estimates that, on average, a family spends 20-30 euros on May Day balloons and party supplies.

Whereas children are pretty flexible in their balloon tastes, adults are far more demanding.

"A couple of grown men were disappointed when they didn't get the Baby Yoda balloon from The Mandalorian series. We ran out of them early on. But the disappointment in adults is greater than the kids’ if they can't get a certain balloon," Kahlos says.

Balloons are mixed waste

Oona Ollila from waste management firm Lakeuden Etappi notes that balloons are incinerable waste.

"They can be put in the trash at home. They have a polyester film surface, but they're also made out of plastic, which is why they are classified as incinerable waste," Ollila explains.

It is a good idea, however, to deflate a balloon before putting it in the garbage. Traditional balloons and streamers are also considered incinerable waste.

Kahlos points out that a balloon can be refilled if it is still intact.

"The balloon can be deflated by inserting a straw through the hole where it was inflated, and stored for next year," she said.

Much like during Christmas, celebration-related waste is generated on May Day. The fat from frying donuts, for example, should be disposed of in the same way as that from a Christmas ham: Cooled in an empty jar and then discarded with incinerable waste or biowaste.

Streamer aerosols and temporary hair dyes are packaged in such a way that they should be considered hazardous waste.

"If the aerosol container still has some product inside, then it is considered hazardous waste. If, on the other hand, the can is empty, it can be placed in the waste container according to the material it is made from," Ollila explains.

Ollila urges people to think about reusing their May Day party supplies. For example, for a May Day picnic, one can pack reusable containers instead of disposable ones.

"I would encourage people to think about how they could celebrate while leaving behind as little waste as possible," she said.

A disposable grill for picnics is also waste that requires a little bit of special attention.

"The metal frame and base go into metal collection, the charcoal is incinerable waste," Ollila said.