In June, Unilever issued guidance on compressing aerosols, designed to encourage its competitors to shrink their cans in line with Unilever’s Compressed technology.

“Some may question the move, but if every spray deodorant was compressed, the industry’s carbon footprint would be reduced by 25%,” says Heidi Williams, marketing manager for Sure and Compressed at Unilever UK. ”Our entire industry needs to help shoppers move away from traditional aerosols. Unilever cannot do that alone.”

The more cans are compressed, the more likely the consumer switch becomes. “Encouraging consumers to swap will always be a challenge, particularly when a product format has remained virtually unchanged,” Williams says. “Unilever believes that with clear industry communication, the necessary transformation can happen. Since launch in 2013, nine million women have used a Compressed antiperspirant [Kantar Worldpanel].”

Although the technology is designed to enable cans to last as long and deliver as much protection as regular aerosols, some say consumers finish compressed cans more quickly. “It’s important that consumers use compressed deodorant in exactly the same way, and spray it for the same amount of time, as the regular cans. Research indicates that consumers may have been spraying the compressed can for longer, as the spray feels softer, and as a result using it up quicker. Education is key here.”

How to shrink your aerosol

1: Establish the packlife of the product to be compressed, and how much you want to compress it by.

2: Reduce the amount of propellant in stages, assessing the product delivery level as you go. Keep the gas composition and pressure the same.

3: Modify the valve. You will need to rebalance the size of the orifices.

4: Active ingredients shouldn’t need to change, but check that the fragrance is stable and that product particle size won’t cause blockage issues.

5: Shrink the can, and don’t forget to shout about it; Unilever wants everyone to adopt its green band pack design.