Chromium is a durable metal used in electroplating, paint pigments (chrome yellow), primers and corrosion inhibitors, wood preservatives, textile preservatives, and leather tanning agents. Chromium exposure may occur by inhalation, ingestion, or skin exposure. Although chromium can exist in a variety of oxidation states, most human exposures involve one of two types: trivalent (eg, chromic oxide, chromic sulfate) or hexavalent (eg, chromium trioxide, chromic anhydride, chromic acid, dichromate salts). Toxicity is associated most commonly with hexavalent compounds; however, fatalities have occurred after ingestion of compounds of either type, and chronic skin sensitivity probably is related to the trivalent form. Chromium picolinate is a trivalent chromium compound often promoted as a body-building agent.

1. Trivalent chromium (Cr³⁺) compounds are relatively insoluble and noncorrosive and are less likely to be absorbed through intact skin or the GI tract. Biological toxicity is estimated to be 10- to 100-fold lower than that of the hexavalent compounds.
2. Hexavalent (Cr⁶⁺) compounds are powerful oxidizing agents and corrosive to the airway, skin, mucous membranes, and GI tract. Most systemic effects are due to inhalation.
3. Chromic acid is a strong acid, whereas some chromate salts are strong bases.

1. Inhalation. The OSHA workplace permissible exposure limit (PEL, 8-hour time-weighted average) for chromic acid and hexavalent compounds is 0.005 mg/m³ (carcinogen). For bivalent and trivalent chromium, the PEL is 0.5 mg/m³.
2. Skin. Chromium salts can cause skin burns, which may enhance systemic absorption, and death has occurred after a 10% surface area burn.
3. Ingestion. Life-threatening toxicity has occurred from ingestion of as little as 500 mg of hexavalent chromium. The estimated lethal dose of chromic acid is 1-2 g, and of potassium dichromate 6-8 g. Drinking water standards for total chromium are set at 0.1 mg/L (100 ppb).

1. Inhalation. Acute inhalation can cause upper respiratory tract irritation, wheezing, and noncardiogenic pulmonary edema (which may be delayed for several hours to days after exposure). Chronic exposure to hexavalent compounds may lead to pulmonary sensitization, occupational asthma, and lung cancer. Additionally, chronic inhalational can cause nasal ulcers and septal perforation.
2. Skin and eyes. Acute contact may cause severe corneal injury, deep skin burns, and oral or esophageal burns. Hypersensitivity dermatitis may result. It has been estimated that chronic chromium exposure is responsible for about 8% of all cases of contact dermatitis. Exposure to chromium-containing felt from gaming tables can lead to a contact dermatitis of the hand known as “blackjack disease.” Chronic exposure can cause painless skin ulcerations known as “chrome holes.”
3. Ingestion. Ingestion may cause acute hemorrhagic gastroenteritis; the resulting massive fluid and blood loss may cause shock and oliguric renal failure. Hemolysis, disseminated intravascular coagulation, acute tubular necrosis, hepatitis, and cerebral edema have been reported. Chromates are capable of oxidizing hemoglobin, but clinically significant methemoglobinemia is relatively uncommon after acute overdose.

Is based on a history of exposure and clinical manifestations such as skin and mucous membrane burns, gastroenteritis, renal failure, and shock.

1. Specific levels. Blood levels are not useful in emergency management and are not widely available. Detection in the urine (24-hour collection) may confirm exposure; normal urine levels are less than 1 mcg/L.
2. Other useful laboratory studies include CBC, plasma free hemoglobin and haptoglobin (if hemolysis is suspected), electrolytes, glucose, BUN, creatinine, liver aminotransferases, urinalysis (for hemoglobin), arterial blood gases, co-oximetry (for methemoglobin), pulse oximetry, and chest radiography.

1. Emergency and supportive measures
   1. Inhalation. Give supplemental oxygen. Treat wheezing and monitor the victim closely for delayed-onset noncardiogenic pulmonary edema. Delays in the onset of pulmonary edema of up to 72 hours have been reported after inhalation of concentrated solutions of chromic acid.
   2. Ingestion
      1. Dilute immediately with small amounts of water orally. Treat hemorrhagic gastroenteritis with aggressive fluid and blood replacement. Consider early endoscopy to assess the extent of esophageal or gastric injury.
      2. Treat hemoglobinuria resulting from hemolysis with alkaline diuresis as for rhabdomyolysis. Treat methemoglobinemia if it occurs.
2. Specific drugs and antidotes
   1. Chelation therapy is not effective.
   2. After oral ingestion of hexavalent compounds, ascorbic acid has been suggested to assist in the conversion of hexavalent to less toxic trivalent compounds. Although no definitive studies exist, the treatment is benign and may be helpful. In animal studies, the effective dose was 2-4 g of ascorbic acid orally per gram of hexavalent chromium compound ingested.
   3. Acetylcysteine has been used in several animal studies and one human case of dichromate poisoning.
3. Decontamination
   1. Inhalation. Remove the victim from exposure and give supplemental oxygen if available.
   2. Skin. Remove contaminated clothing and wash exposed areas immediately with copious soap and water. EDTA 10% ointment may facilitate removal of chromate scabs. A 10% topical solution of ascorbic acid has been advocated to enhance the conversion of hexavalent chromium to the less toxic trivalent state.
   3. Eyes. Irrigate copiously with tepid water or saline and perform fluorescein examination to rule out corneal injury if pain or irritation persists.
   4. Ingestion. Give milk or water to dilute corrosive effects. Do not induce vomiting because of the potential for corrosive injury. For large recent ingestions, perform gastric lavage via nasogastric tube. Activated charcoal is of uncertain benefit in adsorbing chromium and may obscure the view if endoscopy is performed.
4. Enhanced elimination. There is no evidence for the efficacy of enhanced removal procedures such as dialysis and hemoperfusion.