Bis(hydrogenated tallow alkyl)dimethyl quaternary ammonium compounds chlorides
[CAS# 61789-80-8]

Identification

• Classification: Surfactant
• Name: Bis(hydrogenated tallow alkyl)dimethyl quaternary ammonium compounds chlorides
• Molecular Formula: C₃₆^.₄H₇₆^.₈NCl
• CAS Registry Number: 61789-80-8
• EC Number: 263-090-2

Properties

• Density: 0.87 g/mL (Expl.)
• Melting point: 30-45 ºC (Expl.)
• Flash point: 25 ºC (Expl.)
• Solubility: water, g/100mL (25 ºC) (Expl.)

Safety Data

• Hazard Symbols: GHS05;GHS09 Danger
• Hazard Statements: H318-H400-H410
• Precautionary Statements: P264+P265-P273-P280-P305+P354+P338-P317-P391-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Serious eye damage	Eye Dam.	1	H318
Chronic hazardous to the aquatic environment	Aquatic Chronic	1	H410
Acute hazardous to the aquatic environment	Aquatic Acute	1	H400
Chronic hazardous to the aquatic environment	Aquatic Chronic	2	H411
Flammable liquids	Flam. Liq.	3	H226
Skin irritation	Skin Irrit.	2	H315
Skin corrosion	Skin Corr.	1B	H314
Reproductive toxicity	Repr.	2	H361

Discovory and Applicatios

Bis(hydrogenated tallow alkyl)dimethyl quaternary ammonium compounds chlorides belong to the class of quaternary ammonium compounds widely used as cationic surfactants. They are produced by quaternization of tertiary amines derived from hydrogenated tallow, which is itself obtained through the catalytic hydrogenation of animal tallow fatty acids. Hydrogenated tallow typically contains long-chain saturated hydrocarbons, mainly C₁₆ and C₁₈ fatty acids, which after conversion into tertiary amines can be further transformed into quaternary ammonium salts. In these compounds, the nitrogen atom carries two long alkyl substituents from the hydrogenated tallow, two methyl substituents, and a chloride counterion, resulting in a strong cationic charge that governs their physicochemical and biological properties.

The discovery of quaternary ammonium compounds as effective disinfectants dates back to the early 20th century, when their strong surface activity and antimicrobial action were first systematically investigated. Compounds of this class showed the ability to disrupt microbial membranes due to their amphiphilic structure, in which hydrophobic alkyl chains interact with lipid bilayers and the cationic headgroup interacts with negatively charged microbial surfaces. Bis(hydrogenated tallow alkyl)dimethyl quaternary ammonium compounds chlorides were later developed as part of this family, with modifications tailored to improve stability, performance, and compatibility with various applications. The hydrogenation of the tallow feedstock improved the consistency and oxidative stability of the resulting quaternary ammonium salts, making them suitable for industrial-scale production and widespread use.

These compounds found early applications in sanitation and disinfection, where they were used to control bacteria, fungi, and algae in healthcare, food processing, and institutional cleaning. Their dual long-chain alkyl substituents confer enhanced antimicrobial activity compared to monalkyl analogues, making them particularly effective in low concentrations. They have been employed in disinfectant formulations for surfaces, equipment, and water treatment, where they act as broad-spectrum biocides. In addition to antimicrobial use, they were discovered to have strong fabric-softening properties due to their ability to adsorb onto textile fibers and reduce static charge. This led to their incorporation into commercial fabric softeners, dryer sheets, and textile conditioning agents.

In industrial applications, bis(hydrogenated tallow alkyl)dimethyl quaternary ammonium compounds chlorides have been applied in water treatment as algicides and microbiocides, in oilfield operations to control microbial growth, and in the paper industry as antistatic agents and softeners. Their cationic nature enables strong binding to negatively charged substrates, which explains their versatility in such diverse settings. They also act as phase transfer agents in chemical processes, facilitating reactions between aqueous and organic phases.

Although highly effective, these compounds are not without concerns. Since their large-scale adoption, studies have demonstrated their persistence in the environment and potential ecotoxicological effects, particularly in aquatic systems. Their strong binding to organic matter and sediments limits mobility but also slows degradation, raising questions about long-term accumulation. Nevertheless, regulatory frameworks have enabled their controlled use, with safety assessments conducted for specific applications, particularly those involving direct human contact or environmental release.

Research into quaternary ammonium compounds continues to explore their structure–activity relationships, aiming to optimize efficacy while reducing environmental impact. Bis(hydrogenated tallow alkyl)dimethyl quaternary ammonium compounds chlorides remain an important example of how chemical modification of natural feedstocks such as tallow can lead to widely applicable industrial chemicals. Their discovery and application highlight both the benefits and the challenges associated with cationic surfactants that balance functionality, safety, and sustainability in modern industry.

References
McDonnell, G. and Russell, A. D. (1999). Antiseptics and disinfectants: Activity, action, and resistance. Clinical Microbiology Reviews, 12(1), 147-179.
Gerba, C. P. (2015). Quaternary ammonium biocides: Efficacy in application. Applied and Environmental Microbiology, 81(2), 464-469.