Do not touch frosted pipes and valves. This gas is regarded as having adequate warning properties. Ammonia reacts with diverse compounds to form explosive products. Especially avoid contact with silver, gold and mercury. This is a highly toxic, corrosive gas.
Inhalation can cause fatal respiratory damage.
Brief exposure of 50 ppm can result in death within a few hours. Phosgene does not have adequate warning properties so extreme caution must be used when working with this gas. The liquid is highly corrosive and can cause severe burns to exposed skin. This gas is a severe irritant. Inhalation may result in death with exposures of 500 ppm for 30 minutes.