MASSIMO SANDAL
Freelance science writer

Abstract

After decades of attempts, laundry pods are now an ongoing success story of laundry detergent technology. But the shiny, convenient detergent capsules have revealed a dark side, becoming a leading cause of detergent-related poisoning in the household. What happened, and what lessons can be learned?

Whoever loaded a washing machine knows that it can be a messy proposition. One must guess how much soap to use, clean a measuring cup, squint to find the right amount of soap, deal with spilling detergent -you know the drill. In the process, lots of detergent is wasted: most consumers tend to overcompensate when trying to gauge how much detergent is needed. Of course manufacturers hardly complain, but apart from the few dollars wasted by customers on unnecessary soap, the overuse of detergents is an environmental issue. There must be a better way. That is exactly what laundry detergent pods want to be.

The concept looks  simple: a dose of concentrated liquid detergent is encapsulated in a small bag of water-soluble polymer -usually polyvinylalcohol (PVA) or a derivative. Tucked in with the laundry in the washing machine, the bag dissolves without a trace and lets the detergent out. No more measuring cups, no more guessing: just put the pod in, wash, forget. This simplicity hides a lot of tricky R&D challenges – so much that pods are often considered a classical example of successful technological innovation in the detergent market. In fact, it took ...