Hexamine, also known as Hexamethylenetetramine, Methenamine or C6H12N4, is produced by combining formaldehyde and ammonia. It appears as an odourless white crystalline powder or a colourless lustrous crystal that is both highly soluble in water and highly flammable.
Hexamine is used in the production of; explosive compounds, phenolic resins, adhesives, dyes, shrink proof fabrics, motor oils/lubricants, antiseptics, fire starters and pharmaceuticals.
Medically, Hexamine is used to treat urinary tract infections. Its use was temporarily reduced in the 1990s due to the adverse effects when taken in excess, but has since been re-approved due to the fact that bacteria are unable to develop a resistance to formaldehyde.
Hexamine is also used in the EU under the name E239 as a food additive in cheese, canned fish and caviar as a preservative and to prevent fungus and bacteria from forming. However, it is not approved for use in food in the USA, Russia, Australia or New Zealand.
The routes of exposure to Hexamine include; eye contact, skin contact, inhalation and ingestion.
Eye exposure to hexamine may result in redness and slight abrasive damage. The discomfort is only expected to be short term
Skin contact with hexamine is not thought to have harmful health effects, but irritation can occur after repeated or prolonged exposure, with redness and swelling being possible symptoms. If an individual has open cuts or wounds however, they should avoid handling the chemical without the proper PPE as this can result in the chemical entering the bloodstream which will produce greater harm than skin contact alone.
Inhalation of hexamine is mainly a concern for those with an already compromised respiratory function with healthy individuals likely to be unharmed.
When the hexamine evaporates and the ammonia component evaporates into a vapour however, inhalation will be more harmful; causing coughing, vomiting and reddening of the lips mouth, nose and throat. High concentrations of vapour inhalation may cause difficulty in breathing, tightness in the chest, lung damage and even death by suffocation.
In small quantities, the human metabolism allows for detoxification of ammonia. In doses larger than 1-2g however, ingestion is likely to lead to; nausea, vomiting and diarrhoea. Very large doses may produce a drop in blood pressure, collapse, central nervous system disorders, spasms, drowsiness, respiratory paralysis and haemolysis.
If hexamine enters the eye, flush out the eyes immediately with fresh running water remembering to wash under the eyelids as well. Removing contact lenses should only be performed by skilled personnel. Seek medical attention if pain persists.
In the event of skin exposure; remove all contaminated clothing, footwear and accessories and cleanse the affected area with plenty of soap and water. Contaminated clothing must be washed prior to wearing again. Seek medical attention if irritation occurs.
If hexamine dust is inhaled, remove the person from the contaminated area and encourage the patient to blow their nose to ensure a clear passage for breathing. If irritation persists, seek medical attention.
In the event of ingestion, vomiting should not be induced. If vomiting occurs, lean the patient forward or place them on their left side to maintain an open airway and to prevent aspiration. Observe the patient and seek medical advice.
Safety showers and emergency eyewash fountains should be accessible in the immediate area of the potential exposure to the chemical.
Ensure the area has adequate ventilation and install local exhaust ventilation if necessary.
Wear proper PPE, such as safety glasses with side shields, chemical goggles, gloves, overalls, aprons, and respirators. Some plastic PPE is not recommended when handling hexamine, as they may produce static electricity.