Symptoms dependent on the water solubility of the chemical
Highly water-soluble
Anhydrous, ammonia, Hydrogen chloride, Sulfur dioxide, Formaldehyde
Rapidly react with water causing damage to upper airway to vocal cords
Direct tissue damage causing bronchiolar/alveolar edema/airway obstruction and laryngospasm
Nasopharyngeal and tracheal chemical burns, upper airway obstruction
Laryngospasm (can occur immediately upon exposure)
Respiratory distress/failure, hypoxia
Cough
Chest pain
Arrhythmias (hydrochloric acid)
Moderately water-soluble
Damage to moderate-sized airways (bronchioles)
Bronchospasm and wheezing
Poorly water-soluble
Phosgene, Nitrogen dioxide
Inhaled deeply into alveoli
Lack of irritation of mucous membranes can cause them to go undetected
Respiratory distress, tachypnea, cough,<unk>  edema
Anhydrous, ammonia, Hydrogen chloride, Sulfur dioxide, Formaldehyde
Rapidly react with water causing damage to upper airway to vocal cords
Direct tissue damage causing bronchiolar/alveolar edema/airway obstruction and laryngospasm
Nasopharyngeal and tracheal chemical burns, upper airway obstruction
Laryngospasm (can occur immediately upon exposure)
Respiratory distress/failure, hypoxia
Cough
Chest pain
Arrhythmias (hydrochloric acid)
Damage to moderate-sized airways (bronchioles)
Bronchospasm and wheezing
Phosgene, Nitrogen dioxide
Inhaled deeply into alveoli
Lack of irritation of mucous membranes can cause them to go undetected
Respiratory distress, tachypnea, cough,<unk>  edema
Pulmonary chemical agents
Blister chemical agents 
Environmental exposure antibiotics
Lewisite 
High altitude medicine
Sulfur mustard 
Upper respiratory infection
Phosgene oxime 