After the First World War, the military has a strong interest in using
 Respiratory masks showed as a defense mechanism against chemical warfare. This in turn led to the development of efficient and inexpensive filters in the 1930s that were made with resin-injected dust. Further developments led to filters made of very fine glass fibers that could remove particulate matter while providing little resistance to breathing.🎭

Why does the baby's nose look like an elephant's trunk in the picture?

Wars have caused the development of other equipment, for example, the Internet was originally designed for military use

Further developments led to filters made of very fine glass fibers

These improvements led to cost-effective and efficient filters in the 1930s that helped improve safety.

After World War I, the military's interest in using respirators to counter chemical attacks increased.