Project · 2025/262025/26Type: Service concept

Proxit

Tobacco shops buy back used nitrous oxide canisters and trigger collection pick-ups

Your local network for nitrous oxide collection

Corporate partner PAPREC Visit website ↗Cohort 2025/26Theme Sustainability & resources

Proxit – PAPREC (2025/26)
Key fact
2 €Concept payout per returned canister
Team
7 master students
Universities
Disciplines
Industrial Design · Communication Design · Interior Design · UX Design · Civil Engineering · Software Engineering
The project · from brief to prototype

What happened, step by step.

01

Challenge

Recreational 1 L and 3 L nitrous oxide canisters have no accessible disposal route. They end up in household waste, and some explode in waste-to-energy plants, causing damage, forced maintenance and danger to staff.

02

What they built

A buy-back network of local tobacco shops, marked by a sticker. Users hand in canisters and receive 2€ each. When storage is full, the shop requests a Paprec pick-up within 48 hours and is reimbursed in full.

03

Impact

Shops earn 5€ per canister for hosting the collection point. For Paprec, fewer canisters reach waste-to-energy facilities, which become safer, and city streets stay cleaner.

Full project text

The team’s original texts from the project page.

Proxit allows anyone to bring back used nitrous oxide canisters to local tobacco shops in exchange for generous compensation.

Challenge

Over the past few years, 1L and 3L canisters of nitrous oxide have increasingly been used for recreational purposes by younger generations for their euphoric and short-lived effects, but these canisters have created a bigger problem. Indeed, because of the lack of an accessible means of disposal, they end up in the household waste system and land in waste to energy facilities, where some of these canisters explode, causing unwanted damage and mandatory maintenance, on top of being a danger to the facility’s personnel.

Solution

No more need to go to a dedicated recycling center! Proxit transforms local tobacco shops into buy-back relay collection points for used nitrous oxide canisters. With the stores’ flexible schedules and familiar setting, Proxit is designed with the direct needs of consumers and responsible citizens in mind. Identified through a subtle but visible sticker, users simply bring their bottles in the store, hand them over and receive 2€ per canister. Once the storage space is full, the store manager can request Paprec to come collect all the bottles in 48h and receives a transfer with the full amount.

Impact

With Proxit, consumers are given the opportunity to dispose of their nitrous oxide canisters while simultaneously participating in their local economy. In exchange for making their storefront accessible to users, local stores are compensated 5€, more than double the amount per bottle, contributing to a cleaner city and a safer waste to energy facility. Consumers are now motivated to dispose of their canisters in a more responsible way instead of loitering the streets with unwanted and dangerous waste.

Video

Watch the team’s pitch.

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Team · 7 students, 2 universities

Who built it.

Sixtine Nodet
d.school Paris · École des Ponts

Sixtine Nodet

Software Engineer

Kathryn Nguyen
d.school Paris · École des Ponts

Kathryn Nguyen

Accountant

Kieran Janin
d.school Paris · École des Ponts

Kieran Janin

Civil Engineer

Dimple Motwani
ISDI School of Design & Innovation

Dimple Motwani

Industrial Designer & Researcher

Shreyas Mundada
ISDI School of Design & Innovation

Shreyas Mundada

Communication Designer

Palak Toshniwal
ISDI School of Design & Innovation

Palak Toshniwal

UI/UX Designer

Rithika Maniyar
ISDI School of Design & Innovation

Rithika Maniyar

Interior Designer