Benzalkalonium chloride

Chemical Name

  • Benzalkalonium chloride
  • Alkyldimethylbenzylammonium chloride

IUPAC / CAS

benzyl-dimethyl-tridecyl-azanium chloride / 8001-54-5

Physical and Chemical Properties

Benzalkalonium chloride is a white to yellow hygroscopic powder. It is a mixture of various even numbered alkyl chain lengths. It is a cationic surface-active agent belonging to the quaternary ammonium compound group. It is used in the industry as a biocide, preservative agent, phage transfer agent and a surface active agent. It is soluble in ethanol, acetone and water. It foams profusely when shaken and in concentrated solutions has a bitter almond like odor. Its color varies from colorless to faint yellow in solutions.

Mode of Action

It disrupts the intermolecular interactions causing damage to the cell membrane and increased permeability across the cell membrane ultimately causing cell lysis. It can rapidly inactivate enzymes and hence is cidal to all the vegetative forms of microorganisms.

Activity Spectrum

It acts against all bacteria, viruses, fungi and parasites. Its action is better against the gram positive than the gram negative organisms. It does not have any effect on spores and hence can only be used for the purpose of antisepsis. It is widely used as a preservative agent with antimicrobial properties in eye and nasal drops.

Advantages

  • Acitivity is not affected greatly by the pH,but increases with prolonged exposures and increased temperatures.
  • Noncorrosive on metal surfaces
  • Nonstaining and safe to be used on washable surfaces

Disadvantages

  • Readily inactivated in the presenc of organic  substances
  • Incompatible with soaps and cannot be used with anionic surface active agents
  • Salts formed in hard water also reduce its biocidal activity

Toxicity and Side Effects in Humans

There has been some concern over the use of Benzalkalonium chloride as a preservative agent in various nasal and ophthalmic drops.  A review of published literature by Marple et al in 2004 in the journal Otolaryngology and head and neck surgery clearly showed that Benzalkalonium chloride is a safe compound and is not associated with rhinitis medicamentosa. The American College of Toxicology has also concluded from various studies that Benzalkalonium chloride is a safe antimicrobial agent and can be used safely up to a concentration of 0.1%.

Regulatory Information

Occupational exposure limits for Benzalkalonium chloride have not been established but it is classified as a corrosive and an irritant agent by various international agencies.

Safety Measures

Benzalkalonium chloride is a corrosive to the skin , eyes and mucous membranes and hence when handling one must wear protective clothing and goggles to protect the eyes and gloves to protect the hands. The compound must be stored in a cool and dry place away from food and feedstuff. The compound is very toxic to aquatic life and hence all care must be taken not to drain it directly into sewer or drains.

First Aid Treatment

  • On accidental contact with the skin, Benzalkalonium causes redness,skin burns and pain.Wash the area with plenty of cold water for at least 15 minutes.
  • If Benzalkalonium chloride comes in contact with the eyes , wash the eyes near the eye station with plenty of cold water. Since Benzalkalonium chloride is a corrosive compound it is advisable to visit an ophtahlmic  surgeon to assess the extent of injury and its treatment
  • On accidental ingestion, do not induce vomitting as there is danger of causing esophageal tear and bleeding. The patient may need to be under medical observation for at least 24 hours to prevent complications.
  • The toxic fumes of  Benzalkalonium chloride corrode the mucosa of the respiratory tract. The person may need respiratory support  and needs to be under strict medical supervision as pulmonary odema may set in many hours after the accidental inhalation of the fumes.

References

  1. Marple B, Roland P, Benninger M . Safety review of Benzalkalonium Chloride used as a preservative in intranasal solutions: an overview of conflicting data and opinions. Otolaryngol Head Neck Surg 2004; 130(1): 131 ? 141