MATTERS NEEDING ATTENTION

The product is not suitable for anoxic environment, underwater operation, gas pollution. How long is the product not suitable for anoxic environment, underwater operation, gas pollution?It is recommended to replace the protective mask after four hours of continuous use, or to replace the filter cotton mask in time when there is a strong odor due to respiratory resistance. Will the mask get stuffy?Wearing a mask is definitely more stuffy than not wearing one.This product has a breathing valve, which can make it relatively smooth. If the mask is damaged or the breathing resistance becomes too great, should you replace it with a new one? Does the mask smell bad?This product has no peculiar smell, please store it in a dry and ventilated environment without corrosive gas