Benzalkonium Chloride (BAC) Supplier South Africa

What Is Benzalkonium Chloride?

Benzalkonium chloride (BAC, ADBAC — alkyl dimethyl benzyl ammonium chloride) is a quaternary ammonium compound (QAC) biocide — a mixture of alkyl chain homologues (C12–C16 dominant) that is amphiphilic (cationic surfactant character). BAC kills bacteria, fungi, and algae by disrupting cell membrane integrity: the cationic ammonium head group binds electrostatically to negatively charged bacterial membrane components, while the long alkyl chain inserts into the lipid bilayer, disrupting membrane structure, causing leakage of intracellular contents and cell death. BAC is effective against a wide range of gram-positive and gram-negative bacteria, many fungi, and algae, but shows limited efficacy against bacterial spores and mycobacteria.

Cooling Water Biocide Application

In industrial cooling water treatment, BAC is used as a non-oxidising biocide to control bacterial growth (including Legionella pneumophila), algae formation, and biofilm development in cooling tower packing, fill, and basin surfaces. BAC is typically dosed as a slug dose (shock treatment) at 50–100 mg/L, repeated at 1–2 week intervals, or as a continuous low-level treatment (10–30 mg/L) depending on the microbiological control programme. It is compatible with most other cooling water treatment chemicals and is a standard component in Legionella risk management programmes for cooling towers.

Surface Disinfection and Other Applications

BAC is a key active ingredient in surface disinfectants, sanitisers, and hard-surface cleaning products for healthcare, food processing, and institutional use. It is active against SARS-CoV-2 and other enveloped viruses when used at recommended concentrations. In water treatment for recreational water (pools, spas), BAC is used as a biocide adjunct. In oilfield water treatment, it controls sulphate-reducing bacteria (SRB) and general bacterial growth in injection water systems. Terracore Chemicals supplies BAC at 50% and 80% active content in 25 kg and 200 kg drums.