Denmark's life straw principle;

The operation of the life straw is very simple. Just put this plastic tube in water and suck it up through three filters. When users use it to absorb water, sewage first encounters two layers of textile filters, which can remove large impurities and even a long string of bacteria. Then the water enters a compartment, where iodine will kill bacteria, viruses and parasites. The last grid is filled with activated carbon, which can remove parasites that have not been removed before, and can also remove most of the iodine smell.

This 96.4-gram "straw" can filter 700 liters of water, which is enough for one person to use for one year.

It is difficult to filter metals such as arsenic through drinking straws.

Domestic straws can also filter 99.99% of parasites and bacteria in sewage to prevent dysentery. The device can also provide safe drinking water for victims of hurricanes, earthquakes or other disasters, and it can also be a "weapon" that people carry when traveling on weekends. Miguel Westgard, CEO of Westgard Frandsen, said: "Life straws allow individuals to control their own lives and those of their families, and increase the overall household water consumption."

However, the life-saving straw is not perfect. It cannot filter bacteria that can cause diseases such as hepatitis, and it is difficult to filter metals such as arsenic.