The fluid in question is nitric acid, also known as engraver's acid. Engravers often use this acid at a concentration of 60 to 70 percent. The diagnostic key here is the yellowing of the skin at the injury site. This yellowing is characteristic for chemical injury secondary to nitric acid exposure.
Nitric acid is corrosive, and can cause severe burns. Its vapor is corrosive to the respiratory tract, and may cause pulmonary edema that could prove fatal. On contact with skin, liquid splashes with nitric acid may produce severe burns. These burns usually take on a characteristic yellowish hue.
Following ocular contact, serious damage to the eyes may result. Following ingestion, nitric acid may cause immediate corrosion of and damage to the gastrointestinal tract. In addition, exposure to nitric acid fumes may be corrosive to the respiratory tract, and exposure may cause intractable coughing, sore throat, and difficulty breathing. Pulmonary edema may result, may occur up to 48 hours after exposure, and could prove fatal.
Acute effects predominate, and their severity is such that significant repeated or prolonged exposure is unlikely. However, there actually may be issues involving long-term effects such as repeated exposure to high levels producing adverse effects on lung and teeth.