Zinc has been found to be as essential element in the growth of humans and animals. It has been proved that a zinc-rich diet promotes fast healing of wounds. In agriculture, zinc compounds are used as a nutritive supplement to promote growth, in addition to their use as fungicides. Zinc is not regarded as inherently toxic. However, zinc oxide, when freshly formed and inhaled, causes a mild disorder known as "zinc chills" or "oxide shakes". Soluble salts of zinc have harsh metallic taste and if taken internally can cause nausea and purging. Inhalation of zinc chloride fumes can injure the lungs and respiratory tract.