When it comes to hair care, the list of ingredients on your favorite products can often seem like a foreign language. However, understanding these components is crucial for maintaining healthy, vibrant locks.
Today, we’re putting the spotlight on two ingredients that might sound intimidating but are actually hair care heroes: Behenamidopropyl Dimethylamine and Stearamidopropyl Dimethylamine. We will discuss how these ingredients interact, how they are mixed into a product, and how they improve the texture of hair.
While their names may be a mouthful, these compounds play a vital role in keeping your tresses soft, manageable, and shiny.
So, let’s cast aside any fears and dive into the world of these beneficial ingredients, exploring their properties, benefits, and why they deserve a place in your hair care regimen.
Behenamidopropyl Dimethylamine & Stearamidopropyl Dimethylamine: The Connection to Hair Care
Quaternized surfactants are an important ingredient in hair conditioning products. They have been thoroughly researched and tested for their effectiveness in formulating such products.
It is worth noting that human scalp hair naturally has a negative charge in acidic conditions, known as an isoelectric point of 3.67. This is due to the negatively charged sites provided by the amino acids found in keratin protein.
By using cationic ingredients that bond with these negative sites through electrostatic bonding, they can effectively bind to the hair surface.
These cationic ingredients have a distinctive quality – a long fatty carbon chain that, upon binding to the hair surface, provides detangling, slip, and smoothness. This results in less friction between hair fibers and makes it easier to comb, brush, and manage daily.
Cetrimonium Chloride and Behentrimonium Chloride are examples of cationic ingredients which are used to control the static charge density and reduce flyaways. 1,2,3 These ingredients are commonly used for this purpose.
However, concerns have been raised recently about the aquatic toxicity and biodegradation of traditional quaternized ingredients, which are salts with chloride as a counter ion.
Based on scientific data, these ingredients don’t easily break down, which can pose a threat to the aquatic ecosystem. They can also cause build-up on hair after repeated use.
Due to these issues, consumers and hair care experts are looking for alternative hair conditioning ingredients that are both environmentally friendly and provide superior hair conditioning.
Recently, Behenamidopropyl Dimethylamine (BAP) and Stearamidopropyl Dimethylamine (SPA) have gained attention as two multifunctional ingredients extensively used in hair cleansing and conditioning products suitable for all hair types.
The Chemistry of Alkyl Amidoamines (BAP & SPA)
BAP and SPA are types of alkyl amidoamine that contain two distinct functional groups that are bonded to each other within a single molecule.
Specifically, these molecules have a long carbon chain from a fatty acid attached to the amino group through an amido bond. This structure allows for the molecule to have two different functions that can be adjusted and utilized depending on the formulation conditions.
Hence, BAP and SPA can have both non-ionic and cationic properties with varying pH conditions of the hair care product. They behave as cationic when under acidic conditions ( below pH 4.50) while they act as non-ionic above pH 6.0.
In an acidic environment, the alkyl amidoamine can be neutralized with a suitable organic acid, resulting in an amine salt carrying a positive charge density.4
BAP and SPA are hair conditioning agents that have a chemical structure called alkyl amidoamine. This structure makes them easy to break down in the environment and less toxic than similarly-sized quaternary agents. As a result, BAP and SPA are better for the environment and meet new regulatory standards.
Alkyl amidoamine has a chemical structure that makes it easy to break down in the environment, and it is less toxic than other hair conditioning agents that have a similar size of carbon molecules.
Therefore, BAP and SPA are considered to be more environmentally friendly and compliant with the latest regulatory norms.
Neutralizing Agents to Activate Conditioning Agent
Behenamidopropyl Dimethylamine and Stearamidopropyl Dimethylamine are non-ionic until they undergo an activation reaction by reacting with an organic acid. This reaction converts the non-ionic amino group to its salt and generates a unit positive charge.
Thus, the molecule becomes cationic and has a high affinity for hair fiber. Without neutralization, BAP or SPA will not be able to bind to the hair fiber and provide conditioning benefits.
To neutralize BAP and SPA, various types of acids have been tested. Among them, organic acids like Lactic acid, Glutamic acid, and Citric acid are commonly used because of their skin-friendly and chemical nature. Lactic acid is the most preferred option due to its natural moisturizing benefits as a part of the Natural Moisturizing Factor (NMF). 4
How They Differ from Traditional Quat Conditioners
The most commonly used hair conditioning ingredients are the Quaternary salts of Alkykltrimmonium Chloride. They can be found in rinse-off conditioners, leave-in conditioners, deep conditioning products, and styling formulations.
These ingredients belong to a different class of organic compounds where a long fatty carbon chain is attached to a quaternary nitrogen group balanced with a counter ion of chloride or bromide.
Two common examples of quaternary salts used in hair care science are Cetrimonium Chloride and Behentrimonium Chloride. They do not require neutralization or activation and have different physical and chemical properties compared to BAP and SPA. This results in different levels and types of conditioning effects on the hair.
Key Benefits of Using BAP & SPA in Hair Care Products
Both Behenamidopropyl Dimethylamine and Stearamidopropyl Dimethylamine are versatile ingredients that can be used in various hair products such as shampoo, rinse-off conditioners, leave-in conditioner, deep conditioning masks, protein treatments, and even oxidation coloring creams.
Their hair conditioning abilities have been compared extensively with two other cationic conditioning ingredients; Cetrimonium Chloride and Behentrimonium Chloride. The results indicate that they are better at conditioning hair.
The following are some of the main advantages.
The most sought-after and extensively researched aspect of hair care science is hair detangling. Improper hair grooming techniques can cause hair to become tangled, knotted, or twisted.
Exposure to chemical treatments, UV rays, and heat styling can damage the hair fiber’s surface by stripping away the protective cuticle layer. This roughens the hair surface, making it more difficult to comb and brush.
By binding to the hair surface, cationic conditioning ingredients create a slippery effect. To determine how easy hair is to comb and the amount of force required, BAP and SPA were compared to Behentrimonium Chloride and Cetrimonium Chlorides.
The results show that both BAP and SPA are superior at detangling virgin, natural, and chemically treated hair fibers. The effectiveness of these ingredients in detangling depends on the pH of the product and the neutralizing acid used in the formula. Both ingredients demonstrate higher efficacy in detangling at the pH range of 4.00 – 4.30.
When BAP and SPA react with an organic acid, such as lactic acid, they form a salt with a counter ion. This salt can be called Behenamidopropyl Dimethylamine Lacte or Stearamidopropyl Dimethylamine Lactate.
Additionally, these salts can improve the hydrating benefits of conditioning products. Lactic acid is a type of alpha hydroxy acid that naturally moisturizes the skin and offers various benefits to the hair, skin, and scalp.
Less likely to Cause Build up
Behenamidopropyl Dimethylamine and Stearamidopropyl Dimethylamine work differently than traditional quaternary ammonium compound conditioners. They only bind with the hair shaft depending on the pH of the formula. This means that their conditioning level can be adjusted as needed.
Unlike traditional quats which bind to hair shafts and cause build-up, BAP and SPA are gentler alternatives that are less likely to cause a cationic build-up.
The use of BAP and SPA in Color-Safe Shampoos has been proven to prevent color bleeding in hair that has undergone oxidative coloring. This has resulted in longer-lasting color and increased color retention.
Safety & Toxicity
As mentioned earlier, traditional quaternary hair conditioning ingredients can pose a threat to marine life and the environment. They accumulate in river waters from sewage, which is why there are regulations in place to find more eco-friendly alternatives.
BAP & SPA are safe and easily break down, making them a suitable option for regular hair care products.5
Behenamidopropyl Dimethylamine and Stearamidopropyl Dimethylamine are hair conditioning ingredients that offer better conditioning benefits than traditional quaternary ingredients.
They are versatile and can be added to shampoos, conditioners, and masks. These ingredients are also eco-friendly and pose low risk to aquatic life, making them a popular choice among hair care professionals.
1. Zviak, C., The Science of Hair Care. Taylor & Francis: 1986.
2. Schueller, R.; Romanowski, P., Conditioning Agents for Hair and Skin. Taylor & Francis: 1999.
3. Ran, G.; Zhang, Y.; Song, Q.; Wang, Y.; Cao, D., The Adsorption Behavior of Cationic Surfactant onto Human Hair Fibers. Colloids and Surfaces B: Biointerfaces 2009, 68 (1), 106-110.
4. Minguet, M.; Subirats, N.; Castán, P.; Sakai, T., Behenamidopropyl Dimethylamine: unique behaviour in solution and in hair care formulations. Inter. J. of Cosmet. Sci 2010, 32 (4), 246-257.
5. Burnett, C. L.; Boyer, I.; Bergfeld, W. F.; Belsito, D. V.; Hill, R. A.; Klaassen, C. D.; Liebler, D. C.; Marks Jr, J. G.; Shank, R. C.; Slaga, T. J., Safety Assessment of Fatty Acid Amidopropyl Dimethylamines as Used in Cosmetics. International Journal of Toxicology 2019, 38 (1_suppl), 39S-69S.