Benzyldodecyldimethylammonium bromide
[CAS# 7281-04-1]

Identification

• Classification: API >> Synthetic anti-infective drugs >> Disinfectant antiseptic
• Name: Benzyldodecyldimethylammonium bromide
• Molecular Formula: C₂₁H₃₈N.Br
• Molecular Weight: 384.44
• CAS Registry Number: 7281-04-1
• EC Number: 230-698-4
• SMILES: CCCCCCCCCCCC[N+](C)(C)CC1=CC=CC=C1.[Br-]

Safety Data

• Hazard Symbols: GHS05;GHS06;GHS07;GHS09 Danger
• Risk Statements: H301-H302-H314-H315-H319-H335-H400
• Safety Statements: P260-P261-P264-P264+P265-P270-P271-P273-P280-P301+P316-P301+P317-P301+P330+P331-P302+P352-P302+P361+P354-P304+P340-P305+P351+P338-P305+P354+P338-P316-P319-P321-P330-P332+P317-P337+P317-P362+P364-P363-P391-P403+P233-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Acute toxicity	Acute Tox.	3	H301
Eye irritation	Eye Irrit.	2	H319
Skin irritation	Skin Irrit.	2	H315
Specific target organ toxicity - single exposure	STOT SE	3	H335
Acute toxicity	Acute Tox.	4	H302
Skin corrosion	Skin Corr.	1B	H314
Acute hazardous to the aquatic environment	Aquatic Acute	1	H400
Skin corrosion	Skin Corr.	1	H314

• Transport Information: UN 2811

Discovery and Applications

Benzyldodecyldimethylammonium bromide is a quaternary ammonium compound (QAC) consisting of a nitrogen atom bonded to a dodecyl (C₁₂) alkyl chain, a benzyl group, two methyl groups, and a bromide counterion. This compound belongs to the class of QACs developed in the early to mid-20th century for their antimicrobial properties and surface activity. The structure combines hydrophobic alkyl and benzyl groups with a positively charged nitrogen, allowing it to adsorb to microbial membranes, disrupt lipid bilayers, and cause cell death.

The primary use of benzyldodecyldimethylammonium bromide is as a disinfectant and sanitizer. Its cationic nature enables strong interaction with negatively charged bacterial, fungal, and viral membranes, leading to rapid microbial inactivation. It is employed in industrial, institutional, and household cleaning products, including hard-surface disinfectants, sanitizing sprays, and cleaning solutions for medical and food-processing environments. Its broad-spectrum activity and effectiveness at low concentrations make it a reliable component for maintaining hygiene.

In addition to antimicrobial applications, this compound functions as a cationic surfactant and conditioning agent in personal care products. It is used in shampoos, conditioners, and skin care formulations to reduce static, improve hair combability, and enhance softness. The cationic headgroup binds to negatively charged surfaces such as hair and skin, while the hydrophobic tail improves smoothness and spreadability. Its compatibility with other surfactants allows incorporation into various formulations without compromising stability.

Benzyldodecyldimethylammonium bromide also has industrial applications. It is used as a fabric softener, antistatic agent, and emulsifier in textiles, improving fiber softness, reducing static, and stabilizing emulsions. In chemical processing and water treatment, it can function as a flocculant or dispersant, leveraging its amphiphilic and cationic properties to enhance surface interactions and process efficiency.

Environmental and safety considerations are critical for this compound. Like other QACs, it is toxic to aquatic organisms and requires careful handling, proper wastewater treatment, and controlled usage. Exposure to concentrated solutions can cause skin and eye irritation, making protective equipment and safe handling protocols necessary. Its biodegradability is moderate, and formulations are designed to minimize environmental impact while maintaining efficacy.

The development and use of benzyldodecyldimethylammonium bromide illustrate the versatility and effectiveness of quaternary ammonium chemistry. Its combination of antimicrobial potency, surface activity, and conditioning ability has ensured its widespread use across disinfectants, personal care products, textiles, and industrial processes, demonstrating the enduring importance of medium-chain quaternary ammonium compounds in modern chemical applications.

References

2024. Development and Field Application of a New Amphoteric Fungicide for Polymer-Containing Wastewater. Sustainable Development of Water and Environment.
DOI: 10.1007/978-3-031-76148-5_18

2023. Dependence of the Oil-Collecting and Oil-Dispersing Ability of Surfactants on the Kind of Alkyl Radicals in Their Head Group. Russian Journal of Applied Chemistry.
DOI: 10.1134/s1070427223110061

2022. A quantitative high-throughput screen identifies compounds that lower expression of the SCA2-and ALS-associated gene ATXN2. The Journal of biological chemistry.
DOI: 10.1016/j.jbc.2022.102228