Is washing them at 40°C really enough to keep the period underwear hygienic?

We recommend you wash your period underwear at 40°C, as it will help them last longer while maintaining the function and performance of the underwear. The layers in the gusset of the underwear are treated with an anti-odour and antimicrobial treatment that prevents the growth of bacteria. This means that you can wash your period underwear in cooler temperatures and still keep them clean and hygienic. 

Wear, wash, and wear again.