If you hang out in the non-toxic space long enough, you’ll hear “quats” (short for quaternary ammonium compounds) treated like one big bad category. I understand why. Some quats release formaldehyde, pollute waterways, and carry serious irritation and respiratory issues, especially in spray form and in occupational settings. (source)

However, I've learned not all quats are the same. And although they may share the same "chemical family" name, they behave differently and carry different risks. In hair conditioners in particular, quats are basically unavoidable. Lumping them together makes it harder to make practical choices. In this guide, we will break down the differences so you can make smarter product decisions. 

A big thank you to Keith Cretal, Owner and R&D Director of Summit Formulations, a cosmetic manufacturing company based in Boise Idaho for his professional commentary and assistance with this research. 

What Is A Quat?

A quat is a molecule built around a permanently positively charged nitrogen (a “quaternary ammonium” structure). That positive charge is a big reason quats work well as surfactants—they bind to negatively charged surfaces (including hair and many microbial cell membranes). (source)

Quats are often found in: 

• Disinfectants and sanitizers to kill or inactivate microbes on surfaces.
• Laundry products: fabric softeners + dryer sheets to coat fibers to reduce static, increase “soft” feel, and improve drape.
• Hair care to help hair feel smooth and detangled. 
• Eye drops and some topical medications for its antimicrobial qualities.
• Cosmetics/personal care as preservatives.

All quats are synthetic. Some are built from plant-based fatty chains and others from petrochemical feedstocks and others from reacting certain ingredients in a lab, but either way, they’re still man-made ingredients.

I know some “purists” avoid anything synthetic, but that isn’t a science-based safety standard on its own. Plenty of synthetics are well-studied and low risk, and sometimes they’re actually safer or more consistent than natural alternatives that can be more allergenic or contaminated.

“Synthetic” isn’t the hazard. The real question is whether there’s credible evidence of harm in the way it’s used. 

From Keith Cretal of Summit Formulations

"Conditioning Quats Are Not the Same as Disinfectant Quats"

Consumers often hear concerns about certain disinfectant quats and assume that every quat in cosmetics carries the same profile. That is usually an oversimplification.

Many hair-care quats are selected specifically for:

• conditioning performance
• lower irritation potential in rinse-off systems
• compatibility with emulsions
• sensory feel

These are not interchangeable with industrial disinfectant use. 

How Do Quats Differ?

There are dozens of different quats and they show up on product labels under many different names. This had me questioning what the difference is between them, and this is some of the information I found:

• Intended use - some quats are designed specifically for use as a disinfectant, others are created for conditioning. (source)
• Structure - properties like the carbon chain length can affect a quat’s antimicrobial strength, irritation potential and environmental persistence. (source)
• Type - some quats are referred to as esterquats, polyquats, true quats, or quat-adjacent. More on that in the next section. 

Types of Quats

In my research, I saw quats referenced in different ways. While all quats are positively-charged, they do have differences in structure. This structure usually drives biodegradability, build up, irritation potential and feel. 

• Traditional quats (quaternary ammonium compounds) are permanently charged nitrogen-based molecules that do not contain ester bonds. Because of this structure, they tend to be more chemically stable, but that’s also what makes them less biodegradable which means they persist in our environment. There are some exceptions, but most traditional quats are used as disinfectants, preservatives, or strong conditioning agents. 
• Esterquats are a newer subclass of quaternary ammonium compounds that contain one or more ester bonds in their molecular structure. These ester bonds allow the molecule to break down more easily via hydrolysis, which makes them more biodegradable and less environmentally persistent (and also less irritating). For this reason, esterquats are commonly used in rinse-off hair conditioners and fabric softeners as replacements for older quats. (source)
• Polyquats refer to a subgroup of traditional quats and are basically referring to a quat that is part of a larger polymer chain. (source) In hair care, these are usually more surface conditioning and form a film over hair.

I also came across Amidoquats, which actually aren’t true quats because they do not stay positively charged. Sometimes they were referred to as quat-adjacent or amidoamines. They are used to replace the function of a quat in formulas. Usually more biodegradable.

From Keith Cretal of Summit Formulations:

For consumers, the most practical takeaway is that seeing the word “quat” on a label does not automatically indicate a high-risk ingredient—it simply means the specific ingredient should be evaluated in context of its structure, concentration, and intended use. 

What Are The Health Concerns Of Quats?

A lot of the fear surrounding quats is tied to the following:

• Some quats release formaldehyde, linked to cancer. (source)
• Some quats have serious links to asthma and respiratory issues. (source)
• Some quats are documented irritants which can cause issues like dermatitis and even hair loss. (source)
• Some quats are toxic to aquatic life and affect our drinking water. (source)
• Some quats used in eye products have potential to contribute to ocular surface issues with long term use/reliance. (source)
• Some quats have concerns with antimicrobial resistance with overuse. (source)

You will notice that each bullet point says some quats, not all. Which is the purpose of this breakdown. I wanted to objectively review each quat and determine its individual risk profile, rather than lumping them all into one big bad category.

How To Vet Quats

In order to compare quats fairly, I realized I couldn’t rely on blanket claims or fear-based lists. I needed a framework that accounted for nuance. These are the questions I now use when evaluating the quat. 

I also pulled the EWG rating for each one. I have to say EWG was extremely inconsistent with their ingredient ratings. In some cases, they labeled traditional quats as better than esterquats, which contradicts generally accepted science that esterquats are better for the environment. They would also reference the exact same research or source as the reason for their rating, yet rate them differently? EWG was honestly of little help for this particular research.

• What type of quat is it?

From a non-toxic perspective, I strongly favor esterquats over traditional quats whenever conditioning is the goal. Esterquats contain ester bonds that allow them to break down more readily, making them generally less persistent in the environment and often milder on skin and hair.

• Is it biodegradable and what is its effect on the environment?

Because most quats are used in rinse-off products or cleaning products, their environmental fate matters. I look for whether an ingredient is described as readily biodegradable, inherently biodegradable, or persistent in wastewater systems.

Quats that persist in the environment can accumulate in waterways and pose risks to aquatic life. 

• How is it made?

Is it derived from plant sources (preferred) or petro? Does the manufacturing introduce any contaminants, and are those contaminants harmful? Some contaminants have allergenic or irritation concerns, while others have links to cancer.

Nuance: in some cases the same ingredient can be either petro or plant derived and this is where the brand’s sourcing matters. In the comparison chart I indicated whether it’s usually petro or plant, but to know for sure, you’ll have to contact the manufacturer/brand. Plant-derived doesn’t automatically equal safe, however, it is a personal qualifier for my own ingredient standards because I do not allow petrochemicals at Ivy & Fields.

• Are there any reported health concerns?

Next, I look at the human health data. This includes whether the quat has been associated with any adverse effects. Quats with known formaldehyde-releasing properties, strong antimicrobial activity, or consistent links to respiratory issues raise more red flags for me.

If the information was available, I also looked at regulatory bodies and what they had to say. I pay particular attention to guidance from the EU, which tends to take a more precautionary approach than the US when it comes to chronic exposure and environmental impact.

If an ingredient is restricted, capped at low concentrations, or discouraged for certain uses in the EU, that’s meaningful information. It doesn’t automatically make something “toxic,” but it helps determine relative risk between choices.

A Practical Comparison of Common Quats

I scoured the internet for the most commonly used quats in personal care and cleaning products and place them side by side here so you can compare them for yourself. In the next section, I will provide my personal take.

My Quats Analysis

I will say this research was TOUGH. EWG in particular was a head spinner. They rated traditional quats more favorably than esterquats and cited the same reason/research. It made no sense!

Are quats perfect? No. But this breakdown at least helps inform better choices, and most importantly: informed choices.

When it comes to disinfecting purposes, I believe quats are completely unnecessary and easily avoidable. There are so many safe disinfectants on the market with matched efficacy, like Hypochlorous Acid and Vinegar.

But when it comes to hair conditioning, a quat-free conditioner is rare, and may not work on all hair types. 

What I love about building my comparison charts is that I can easily eliminate poor choices by simply applying a criteria. If you’re curious on how I landed on the below list, I like to use a process of elimination approach.

• First, I removed all quats that are usually sourced from petro. Avoiding petro-ingredients is a standard I have set for Ivy & Fields.
• Next, I disregarded all quats that had the bigger biodegradability and formaldehyde concerns. 
• I also disregarded all the Quaterniums, because other than Quaternium-15 (which releases formaldehyde), none of them had any data available. I would rather be conservative. It’s possible they may be low risk, but didn’t really find data to support it either way, and EWG gave opposite ratings when used in personal care vs. cleaning products. Confusing!

Safer Choices

I wish my analysis were more cut and dry, but these take some explaining, so here we go:

This first group is arguably the more “natural-leaning” route. These quats are sourced from guar beans and honey so they have more of a natural origin if that is important to you. Of course, all quats are still synthetic, but the biggest risks here seemed to be natural contaminants/reactions from the raw materials. These are the only quats I found that were COSMOS and/or ECOCERT-approved.

• Guar hydroxypropyltrimonium chloride 
• Honey Hydroxypropyltrimonium Chloride

From Keith Cretal of Summit Formulations

Its helpful to clarify that ingredients such as Guar Hydroxypropyltrimonium Chloride and Honey Hydroxypropyltrimonium Chloride may appeal to consumers seeking more naturally derived raw material origins, while still recognizing they are chemically modified functional ingredients. Overall, approach can educate consumers on a more thoughtful approach when selecting products. 

Other decent options might be Dipalmitoylethyl hydroxyethylmonium methosulfate and Distearoylethyl dimonium chloride. These are esterquats (not traditional quats) and I didn’t find any direct concerns with these ingredients. It also appeared on more natural-leaning supplier websites which is usually an indication of at least being a better choice.

• Distearoylethyl dimonium chloride 
• Dipalmitoylethyl hydroxyethylmonium methosulfate 

Okay Choices

These next ones had some potential, but ultimately did not make my safer choices list for the reasons stated below.

• Stearamidopropyl Dimethylamine
• Brassicamidopropyl Dimethylamine
  

These have a risk of nitrosamines and DMAPA residuals (skin irritant). It is not zero, but it is not rampant either. Most formulators specifically work with this ingredient to avoid the risk. Nitrosamines are a concern because they are highly toxic (but food and drugs are cited as the biggest exposures, not hair care).

The biggest risk with these is actually DMAPA residuals if not properly purified which can irritate some skin. Ultimately, I decided against them because of some petro origins for the raw materials. However, they are not the worst choice, and better than others on the list. So I'd label these a maybe.

More on Nitrosamines:

The important part: Nitrosamines don’t come from a single ingredient—they form when a nitrosatable amine reacts with nitrite contaminants under the right conditions. If the conditions do not exist, nitrosamines cannot form.

Naturally, the next question is what are the conditions? The main risks are nitrite-contaminated water or raw materials. Some preservatives like sodium benzoate or potassium sorbate can contribute indirectly by creating a more acidic environment, but they don’t form nitrosamines on their own. Proper purification, controlled pH, proper storage, and clean sourcing are what prevent this from being a real-world issue.

Bottom line: for nitrosamines to be a real risk, you need all three: (1) Nitrosatable amine (these quats have that) AND a (2) Nitrosating agent AND (3) Favorable conditions. If you don’t have all 3, nitrosamines cannot form.

What About Behentrimonium Methosulfate?

I also want to comment on Behentrimonium methosulfate (BTMS), because it is so commonly used in more cleaner hair care brands. It's probably one of the quats I see the most.

• Behentrimonium methosulfate (BTMS)

The biggest concern here is that BTMS is a traditional quat with bigger biodegradability concerns than others. It is generally safe for consumers in small concentrations, but the widespread use and accumulation in our environment are the bigger concerns. 

Again, it’s a better choice than others on the list, but if you can avoid it, you could be doing the environment a favor.

From Keith Cretal of Summit Formulations

Despite the name methosulfate, this is not the same as sodium lauryl sulfate (SLS) or cleansing sulfates. It does not function as a harsh detergent. The “methosulfate” refers to the counterion naming chemistry, not a stripping cleanser. 

Other Ingredients Still Matter

That said, don't forget to check the rest of the ingredients in a product even if they contain a safer quat choice. You will still want to review a product label in full to avoid other concerns like synthetic fragrance, sulfates, parabens, ethoxylates, siloxanes, or harsh preservatives. 

My Own Hair Journey

I have, with mixed success, been able to use my Chagrin Valley Apple Cider Vinegar Hair Rinse as my exclusive hair conditioner. Paired with a non toxic shampoo, and routine baking soda rinses, this has kept my hair feeling clean with less noticeable hair loss.

I also recently stocked a quat-free conditioner by Roots & Leaves that I liked after a few washes! We now have a traditional-feeling (quat-free) hair conditioner at Ivy & Fields!

Soft vs. Hard Water & Hair Care

One of the reasons I've personally struggled so much sourcing non toxic shampoos and conditioners that actually work is because I live in a hard water area.

Generally, saponified hair products (most "natural" shampoos are saponified) or gentle cleansers work best in soft water. If you are lucky to live in a soft water area, or have a water softening system or filter in your home, then you will have much more success with gentler hair products.

If you have hard water, finding a shampoo and conditioner that plays nice with your hair is hard to do. If gentler cleansers did not work for you, then seeking a hair conditioner with safer quats can be a good compromise.

A shampoo with a chelating ingredient can also help combat hard water. Chelators bind to minerals in your hair from hard water so they can be more easily rinsed away. This helps reduce that filmy/greasy hair feel. I do not recommend chelators like EDTAs. Gentler choices would be Tetrasodium Glutamate Diacetate, Sodium Phytate, Glucono Delta-Lactone, and even Citric Acid.

Your Turn: Two Ways To Approach Quats

Now that you know a little bit more about quats, the question is how will you apply this information to your product choices? There are two ways I believe you can approach quats:

Option 1: Avoid all quats

This is the most purist option for sure and it's definitely possible. The pros are that you would be eliminating absolutely any risk associated with using quats, no matter the type of quat. The big con is that this is virtually impossible in hair care. 

Almost all hair care contains some form of quat. You can find shampoos without quats quite easily (we have some in our shop using safe surfactants too), but hair conditioners are much harder (we just found this one). We also did manage to find a leave-in hair conditioner and heat protectant without quats (find it here).

An alternative to traditional hair conditioners is to use an Apple Cider Vinegar Hair Rinse which I detail more about in this article. Combining this with the leave-in and then this Hair Butter for softening your hair can be a combo that you consider! It doesn't work for everyone, but it has generally worked for me and my hard water is pretty hard!

But Keith Cretal of Summit Formulations cautions:

Avoiding all of them assumes they are equivalent, which is usually not scientifically accurate. Certain haircare quats (such as BTMS or specific polyquaterniums) are used because they are extremely effective at:

• detangling
• reducing static
• smoothing cuticle damage
• reducing breakage from combing
• improving softness

Removing them can significantly reduce performance, especially for: curly hair, bleached hair, coarse hair, damaged hair, long hair prone to tangling.

Option 2: Use safer quats

I still believe it's quite easy to avoid all quats, except for hair conditioners. There’s no need for these harsh quats in your home cleaners, when products with vinegar, and hypochlorous acid are just as effective.

But if the natural options have not worked for you, I would recommend at least sticking to the safer hair quat options on this list. 

In general, rinse-off products are the least concerning category in toxicity, and all major regulators agree (regulation surrounding rinse-off products is usually more relaxed than for leave-on products). 

There is of course, the third option of "good hair, don't care". If that's you and you truly don't care, then I love that for you 😂. I, however, am a non-toxic girlie and I like to make the best possible choices without sacrificing too much performance. 

Keith Cretal of Summit Formulations adds:

A better approach is "selective avoidance." Instead of avoiding all quats, a more balanced strategy is:

• avoid aerosolized disinfectant quats if concerned
• favor biodegradable / milder conditioning quats
• choose rinse-off over leave-on when possible
• patch test if sensitive
• and focus on overall formula quality 

Final Remarks

I hope you enjoyed this research project on quats. Honestly, this was one of the tougher ingredient deep dives I have done, mostly because the information was so hard to find in the first place. As always, I welcome the community to share their own knowledge. If you have something to add, our contact form is always open.

We do these research projects because we love doing them. But if you found it helpful and want to support the work, come shop with us at Ivy & Fields. Every product in the shop has been personally researched and tested to the same standard you just read. No pay-to-play, no greenwashing, no blind adds. Built by someone who just wanted a better way to shop small and non-toxic.