What to do in case of an overdose?

Place patient in a horizontal position to minimize circulatory problems. Since the substance wears off after a few minutes, just wait.
As you may know from baby care, nitrite and nitrate form
methemoglobin by binding to hemoglobin, thus block oxygen transfer. In case when ingested by mouth this could cause asphyxiation because methemoglobin will not fade out so quickly.

When swallowed, it is necessary to induce vomiting immediately and call medical emergency in your country!!!

Skin contact causes irritation and rashes - in case of contact wash affected area under running water.