How to Treat a Rash from DIY Baking Soda Deodorant

Having to deal with a sudden rash, redness, itchiness, pain, swelling or rough, leathery skin in the armpits is nobody's idea of a good time. Unfortunately, this has become an unexpected and painful reality for a heck of a lot of people who are simply trying to live a greener life.

Information (and misinformation) about some commonly used ingredients in deodorants continues to flourish, causing many to seek alternatives to commercially produced deodorants.

A great number of the 'greener’ (and DIY) deodorant solutions involve applying a chemical compound more commonly known as baking soda to the delicate skin of the armpits, which can causes a wide range of unfortunate and unpleasant reactions.

In Theory, it Sounds Like a Good Idea to Use Baking Soda as a Deodorant

The logic of reaching for baking soda is understandable: it is easily obtainable at any supermarket and great for many household uses: cleaning, spot removal, etc.

It’s also a great deodoriser (ever hear of placing an open box of baking soda in the refrigerator to remove odors? It works)

So how could it possibly be harmful?

What folks are overseeing in their otherwise admirable quest to go green is that baking soda (or sodium bicarbonate) is a chemical compound that can function as an irritant with prolonged skin contact.

Applying it to armpits is not only prolonged direct contact, but prolonged contact with a sensitive area.

What Happens With Prolonged Skin Contact to Baking Soda

There are a variety of common reactions to baking soda deodorant

• Discoloration (reddish, brownish or general darkening) of the skin

• Thickening, leathery skin

• Slight rash

• Heavy, itchy rash

• Rash with painful pustules

Yikes!

Damage Done, Now What?

Because so many of you have asked, I've put together a few tips for dealing with the discomfort of ‘baking soda burn’ to help get your pits back on track as quickly as possible.

How to Treat Baking Soda Burn

Contrary to what you might have read or heard, the rash/itchiness/reaction you are experiencing is NOT due to ‘detoxing from commercial deodorant’. It is more likely a reaction to the baking soda in the deodorant you used.

First thing to do is put that deodorant away and refrain from using any deodorant until your pits are once again happy and healed.

Depending on how serious your discomfort is, consider seeing a doctor. This may sound like overkill, but some folks have had quite serious reactions that needed immediate medical attention. If you are in even the teensiest bit of doubt – get your doctor to check your pits.

If your skin has become thick, leathery and/or discolored but is otherwise pain-free, you can probably self treat with one or more of these methods

• Apply cool compress (wet a clean soft cloth with cold water, wring out and place on armpits)

• Apply pure aloe vera to the affected area (if you can source aloe vera juice, try misting it on the pits. If you can source aloe vera gel, apply a thin layer to pits)

• Mist the affected area with a hydrosol (rose, lemon balm, chamomile and lavender are quite calming)

• Cucumber cooler. Line a small bowl with a soft cloth. Grate cucumber into the cloth. Gather up edges of cloth to form a little ‘bag’ (like pictured above) and gently dab the pits with the bag.

• Make a colloidal oat solution and use to gently ‘wash’ the pits. This can also be made using regular rolled oats and water (drop a teaspoon of oats into a bowl of water and stir — the liquid should be runny but slightly ‘gloopy’). To use, dip a clean soft cloth in the liquid, wring out lightly, and gently dab the armpits.

• After washing/rinsing, help soothe the area with a small application of pure coconut oil. Be gentle!

• While your pits are healing, an acidic mixture such as fresh lemon juice or apple cider vinegar diluted in water (about 1:10) can be carefully dabbed on unbroken skin

I wish you a speedy recovery and happy pits!

Make Your Own Botanical Deodorants

If you are interested in learning how to make your own effective botanical deodorants (and other personal care products) with simple, easy-to-source ingredients, check the e-book below (available in both English and Spanish). The 3 bottles on the right of the picture below are deodorants.

Make Your Own Preservative Free Natural Cosmetics With 21 Ingredients

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About Aluminium and Antiperspirants

Today we're looking at a popular antiperspirant ingredient that has (understandably) caused both confusion and concern in many.

The ingredient is aluminium chlorohydrate.

Let's start with the first part of that name: aluminium (spelled as aluminum and aluminium but it's the same substance).

Aluminium is Everywhere

Aluminium is the third most naturally abundant element in the environment (after oxygen and silica). It is present almost everywhere – in food and water as well as all kinds of consumer products.

Aluminium is mined from bauxite ore. We can thank the French geologist from Les Baux – Pierre Berthier – for discovering that aluminium was predominant in this ore in 1821 (and I know you've already guessed why the ore is named bauxite). Bauxite is fairly easily mined because it is almost always found near the surface of the terrain.

Aluminium Compounds

Aluminium is more than the metal we all know as packaging, foil wrapping, metal siding, and framework for light structures. It is also available in other forms, such as aluminium salts (or compounds).

Aluminium compounds are a water-soluble group of aluminium complexes, and aluminium chlorohydrate is composed of hydrochloric acid, water, and aluminium.

Aluminium compounds are commonly found in commercial antiperspirants. (REF) and one of the most commonly used is our star ingredient today: aluminium chlorohydrate.

How Aluminium Salts Work in Antiperspirants

Aluminium salts are quite effective antiperspirants and work in 2 ways:

1. By reacting with the electrolytes in sweat. This reaction causes a gel-like substance to form and plug the duct of the sweat gland. The plug prevents the gland from excreting sweat until the natural sloughing off of skin cells under the arms removes it.

2. By interacting with the keratin fibrils (read: very fine fibers) in the sweat ducts – again forming a plug that prevents sweat from reaching the surface of the skin.

While it is an excellent antiperspirant, the concerns about this ingredient have been from fear of absorbing it through use.

What Science Says about Aluminium Chlorohydrate Absorption

In 2001, aluminium chlorohydrate absorption was tested and the study concluded:

"Results indicate that only 0.012% of the applied aluminium was absorbed through the skin. At this rate, about 4 microg of aluminium is absorbed from a single use of ACH (aluminium clorohydrate) on both underarms. This is about 2.5% of the aluminium typically absorbed by the gut from food over the same time period. Therefore, a one-time use of ACH applied to the skin is not a significant contribution to the body burden of aluminium." (REF)

This sounds promising doesn't it?

I thought so too at first – especially since this study has been quoted numerous times.

But let's look at what the Scientific Committee on Consumer Safety (SCCS) had to say after examining it in detail:

"The shortcomings of this study are that it was not done in accordance with good practice (GCP) and it was performed using only 2 volunteers." (REF)

Testing only a one time application on only two volunteers?

Hmmm.

Most folks who use antiperspirants use them daily - not just one time. And 2 people doesn't seem like a representative group, does it?

The Journal of Inorganic Biochemistry published an article entitled Aluminium, antiperspirants and breast cancer in 2005 that stated:

"Aluminium is known to have a genotoxic profile, capable of causing both DNA alterations and epigenetic effects, and this would be consistent with a potential role in breast cancer if such effects occurred in breast cells". (REF)

The article continues:

"the effects of widespread, long term and increasing use remains unknown" (REF)

Find the full article here

If you go digging around bit, you'll find there are numerous studies and papers to be found on this topic. As it happens, the SCCS has examined a great number of them and in 2014 concluded the following about absorption of aluminium through skin:

"The available studies are of poor quality and have not been carried out according to the current requirements. In the absence of any better data to estimate skin penetration of aluminium, the SCCS considers that aluminium absorption after dermal exposure is still very poorly understood. A conclusion on internal exposure to aluminium following cosmetic use cannot be drawn." (REF)

And finally:

"The authors conclude that these observations do not formally identify aluminium as a breast carcinogen, but challenge the safety ascribed to its widespread use in underarm cosmetics."

Find the full paper here.

In May of 2022, the SCCS submitted their latest assessment, Safety of Aluminium in Cosmetics - Submission III which concluded the following

"The SCCS considers that aluminium compounds are safe when used

a. in non-sprayable product categories at the maximum levels indicated in Table 4;

and

b. in sprayable antiperspirant products, provided that the maximum percentage of particles with 10 μm diameter does not exceed 20% of the total aerosolised particles

The SCCS could not assess safety of aluminium compounds in sprayable applications other than antiperspirant."

They were also asked to consider safety levels when aluminium exposure came from a combination of sources and offered the following conclusion:

"The aggregate exposure to aluminium from cosmetic and non-cosmetic sources may exceed safe limits."

In short, there is no clear answer. Tallying up the combined exposure from food, pharmaceuticals and cosmetics may exceed safe levels of exposure.

Find more and download the SCCS submission here.

It (still) looks like more studies need to be undertaken, and judging from the SCCS’s comments, quality studies need to be undertaken.

Meantime, I can only conclude with this:

You should always choose and use what is right for you.

You: Would you use it, Lise?

Me: I prefer not to.

More about Aluminium, Allergies, and Antiperspirants

Antiperspirant and deodorant allergy test results:

"The most commonly occurring allergen in 107 tested deodorants and antiperspirants was fragrance - perfume." (LINK)

Agency for Toxic Substances and Disease Registry on Aluminium:

"An average American adult consumes about 7-9 mg of aluminium every day through their food." (LINK)

Human health risk assessment for aluminium, aluminium oxide and aluminium hydroxide (LINK)

Scientific Committee on Consumer Safety SCCS : The SCCS opinion on the safety of aluminium in cosmetic products (2014) (LINK)

A preliminary study og the dermal absorption of aluminium from antiperspirants using aluminium-26 (LINK)

Aluminium zirconium tetrachlorohydrate gly (another aluminium compound used in antiperspirants and allowed by the FDA at up to 20% of a formulation) (REF)

Frequent use of underarm cosmetic products (containing aluminium) may lead to an accumulation of aluminium in breast tissue (LINK)

FDA Code of Federal Regulations for Aluminium Chlorohydrate (LINK)

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The book below (available in both Spanish and English) shows you how to make your own all natural preservative free deodorants with a shelf life of up to 6 months.

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Deodorant Part 3: About Potassium Alum

Today we're going to look at an ingredient that has been a staple in my stockroom (and many of my deodorant formulations) for several years. It can count itself among the few ingredients that have an easily pronounceable INCI name: Potassium alum.

It also has several common names:

• Alum

• Potassium alum

• Potash alum

• Potassium aluminium sulfate

Potassium alum is (perhaps understandably) sometimes confused with other ingredients.

What is Potassium Alum?

You have probably already seen potassium alum many times as it is shaped, packaged and sold as 'natural crystal deodorant'. Pictured at the top of this post are a couple of examples.

Briefly described, potassium alum is a naturally occurring chemical compound that develops when sulphide and potassium-bearing minerals come into contact with oxygen molecules. When this happens, potassium alum appears as encrustations/crystals.

While potassium alum can be found all over the planet, it is predominant in Europe, North America, and South America.

Potassium alum is also described as the double salt of aluminium and potassium.

Although it is naturally occurring, potassium alum can be man-made. From what I understand, you have to be a mineral-savvy person to be able to distinguish between a man-made and naturally occurring potassium alum crystal. The man-made crystals have a presence of aluminium hydroxide which gives them a slightly different opacity and may also make the man-made alum a mild skin irritant as compared to the naturally occurring substance.

Differentiating Between Aluminium, Aluminium Salts, and Potassium Aluminium Sulfate

Seeing so many mentions of aluminium can be enough to get some folks worried (more on aluminium and cosmetics in an upcoming post), but let's take a closer look.

Checking the CAS numbers of these can be helpful. These are unique identifying numbers that are assigned by the Chemical Abstracts Service.

If 2 ingredients happen to have the same CAS number (like in this example), they are chemically identical.

Aluminium

is the third most naturally abundant element/metal on the planet - mined from bauxite ore and used to make packaging, wires and many other things.

Aluminium CAS number: 7429-90-5

Aluminium Salts

such as aluminium chlorohydrates and/or aluminium chloride are commonly found in commercially made antiperspirants, as an adjuvant in vaccines, and as an antacid in some stomach treatment products.

Aluminium chlorohydrate CAS number: 12042-91-0

Aluminium chloride CAS number: 7446 70 0

Potassium Alum

is the double salt of aluminium and potassium and also known as crystal deodorant (with more uses listed below).

Potassium alum CAS number: 10043-67-1

Potassium alum is listed as GRAS (Generally Recognised as Safe) by the FDA.

Potassium Alum's Multiple Uses and Properties

Potassium alum is used in numerous industries, such as water-purification, dyes, and leather tanning.

It may also be sitting in your kitchen cupboard right now if you have happen to have baking powder in the house because potassium alum is the acidic component of some baking powders.

Potassium alum has a history of use as an astringent, and also boasts anti-sceptic properties.

If you happen to know someone who shaves 'the old fashioned way', you will probably find they have a small bar of 'shaving alum' at hand. Shaving alum is 100% potassium alum and a very effective styptic bar that stops bleeding from minor cuts.

Potassium Alum's Deodorising Abilities

When I started working with potassium alum, I combined it with other ingredients to create a 'cocktail of actives' for my deodorant formulations.

Over time, I discovered it functions quite well on its own and can provide all day deodorising action when applied with care (read: one single swipe doesn't do it, you have to wet the crystal and apply slowly).

Potassium alum is available in powder form from many cosmetics suppliers and is relatively easy to work with.

Next time we look at deodorants, we'll be looking at aluminium and antiperspirants.

More about Potassium alum

PubChem

Patent for preparation method of potassium alum

How to Make Potash Alum (potassium alum)

Do Tell

Have you ever used a natural crystal deodorant? Did it work for you?

The books below (English and Spanish version) include 3 natural, self preserving deodorant formulations.

Make Your Own Preservative Free Natural Cosmetics With 21 Ingredients

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Deodorant Part 2: The Make-up of Deodorant

Welcome to the second part of this mini-series on deodorant. Today, we're going to examine what goes into a deodorant and take a peek at a few ingredients.

Take Your Pick

Deodorants come in numerous forms such as stick, roll-on, cream, gel, and spray.

From a formulating viewpoint, the composition of a deodorant is not all that different from other personal care products.

Deodorants consist of 4 main ingredient categories

• Base/Carrier ingredients

• Consistency giving ingredients

• Active ingredients

• Bells and Whistles ingredients (my term)

Base Deodorant Ingredients

The base of a deodorant could also be described as the carrier of the other ingredients. It is generally what there is most of in the formula (and you will often find it listed first if you have a tendency to read cosmetic ingredient labels).

Examples

Roll ons and gels are - for the most part - water-based. Although I haven't come across it, it wouldn't surprise me if there was an oil-based roll-on somewhere on the market. It's definitely possible to make.

Creams and (pump) sprays are generally also water-based.

Stick deodorants may have a base that is predominately a butter (or mix of butters) and might be combined with fatty alcohols (stearic acid, cetyl alcohol, etc).

Deodorant Consistency Givers

It's pretty easy to guess what these ingredients do: they help create the desired texture and feel of the end product.

Examples

A cream deodorant is by definition an emulsion (a combination of fats and waters). In order to get fats and waters to stay together, things such as emulsifiers are required to help create the desired consistency and feel. There are numerous emulsifiers to choose from and they can be either synthetic/petrochemical or plant based. A roll-on deodorant can be an emulsion.

A stick deodorant could be in the unique position of having a base ingredient that also functions as consistency giver. One example could be a plant butter based deodorant stick.

A gel (which could also be a roll-on) gets its texture from gelling agents (polymers). These can be everything from natural gums such as locust bean gum, gellan gum, methylcellulose, or konjac glucomannan to petrochemical options such polyacrylic acid (commonly known as carbomer).

There is a plethora of gelling agents available today (as opposed to when I started developing deodorants). My own personal favorites for creating smooth roll-on delivery with a non-tacky feel has been to combine a few easily sourced biopolymers (natural gums) such as guar, carrageenan, and xanthan.

About Synthetic Consistency Givers

Some people worry about working with synthetic polymers and emulsifiers, but from a health standpoint, there is no need for concern. I have to date not come across a single petrochemical/synthetic emulsifier or gelling agent with any substantiated health hazards.

Because I have extremely limited experience working with synthetic ingredients, I'm afraid I can't share any tips on working with them, but I can pass on this little nugget of information from a couple of colleagues who work 'across the natural/synthetic border': not everything petrochemical mixes well with everything natural. So if you are imagining your own unique combination of natural and synthetic ingredients, expect to do some experimental batches to get your desired end product.

Deodorant Active Ingredients

Before we get into the actives, let's briefly touch on the difference between deodorant and antiperspirant.

As the name deodorant suggests, its function is to de-odorise = prevent/remove odor. In short, a deodorant doesn't deal with how much or little you may or may not sweat. The gent pictured at the top of this post has clearly found a deodorant that works for him, although his shirt reveals he might feel more comfortable using an anti-perspirant.

An antiperspirant is - as the name suggests - designed to prevent or slow down perspiration. By preventing sweat, you also help create an environment where bacteria cannot grow or thrive. We'll be looking at anti-perspirants (and some of the controversy surrounding them) in a future post.

Back to de-odorising.

The list of available actives today is much longer and more varied than it was when I started making my own deodorants.

If you prefer to order from a cosmetic ingredient supplier (as opposed to making your own extracts and ingredients), you might consider triethyl citrate, potassium alum, farnesol, magnesium or even aluminium compounds (which we will be looking at in more detail in an upcoming post). Today, some suppliers even offer their own ready-to-use 'deodorant blends' to make creating your own deodorants a snap.

For more purist natural deodorants, you might consider zinc oxide, clays, arrowroot starch, activated charcoal, essential oils, or even everyday household staples such as apple cider vinegar. Baking soda has been popular with many DIY'ers, but many have also learned the hard way that long term skin exposure to baking soda often causes irritation and rash. There are commercial deodorants that contain baking soda, but check the ingredients label. The sodium bicarbonate (baking soda) is generally listed after the preservative which puts it at under 1.0% of the total.

For 100% 'roots' deodorant actives (where you forage/grow and process your own plants-to-final-product), consider cleavers, sage, clary sage, mint, and lavender.

Over the years, I have tried several types of deodorant actives (also the easy-peasy deodorant blends) and most have proven to be quite effective. In more recent years, my deodorants have become more minimalistic and 'roots' and have also proven to be quite effective.

Deodorant Bells and Whistles

These are the extras and include ingredients such as fragrance and color, but could also be additional moisturising agents or botanical extracts.

Even though essential oils are already mentioned above as actives, they should also be listed in this category as they also function as fragrance. My favourite essential oil guru Robert Tisserand refers to essential oils as 'functional fragrances' – an accurate description for these multifunctional and powerful ingredients.

To a purist, extras might be considered unnecessary, but to many consumers, the extras can make or break a sale. What's the first thing most people do when checking out a product? They sniff it. If the fragrance is unappealing, it goes back on the shelf. If the product doesn't have an appealing color it may be doomed to stay on the shelf as well.

About Aerosol Deodorants

Aerosols (pressurised sprays) are put together a little differently than the deodorants listed above.

The base and main active of these deodorants are often a compressed gas (butane, isobutane, propane) combined with an alcohol (ethanol, isopropyl alcohol) and a few additional ingredients. This kind of deodorant is not do-able in a DIY setting.

Stay tuned for more armpit and deodorant-related fun in coming posts!

Make Your Own Preservative Free Natural Cosmetics With 21 Ingredients

This book is also available in Spanish.

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About Deodorant - Part 1

Welcome to the first post in a mini-series about deodorant.

Yay! (I hear you thinking)

As we examine what exactly goes on in armpits (and in the products we apply to them), we'll meet some fascinating chemicals that may sound a little scary and hard to pronounce, but I'm betting you find yourself falling for one or 2 of them before we're done discussing armpit related ingredients.

Deodorant Isn't Very Sexy

Admittedly, I am a reluctant developer of deodorant. It really didn't interest me to work on such an 'unsexy' kind of product when I started out. It wasn't until my husband and I had exhausted all of the available commercial brands with absolutely no armpit satisfaction that I got serious about developing my own.

At that time, there weren’t many 'natural' brands on the market. Those that were offered a selection of products that were either too sticky or too gummy-feeling or didn't work more than a few hours. The 'non-natural' brands (which we also tried) had even less going for them – they were too tacky, grossly over-scented, and every last one of them seemed to irritate our skin in one way or the other.

There was nothing for it but to get cracking on developing my own.

Today, I can look back and say I'm glad I did.

The Quest For The Perfect Pit

One would think it a relatively simple matter to put together a non-sticky, effective-yet-mild, mildly-scented, skin- and planet-friendly deodorant.

In theory, yes.

In reality, it became a formulating quest that spanned numerous years and countless batches before I started feeling satisfied with both application, scent, and performance.

Going Green

Because I work predominately with plant-based ingredients, the goal has always been to use as many organic and planet-friendly ingredients as possible (and there you have my definition of green).

To make a 'green' deodorant, there is a fairly limited range of choices as to active ingredients, yet more than one might initially expect. The ideal solution has been a question of combining several different active ingredients in the right proportions (and it’s getting both combination and proportions just right that has been the biggest challenge).

We’re going to be looking at the make-up of deodorants, but first let's take a peek at what it is that makes a deodorant necessary/desirable in the first place.

Sweat is Unscented by Nature

Human sweat is pretty odorless by nature. It isn't until bacteria is introduced to the humid environment that is armpits that odor even enters the equation.

When bacteria meets sweat, it releases a substance called trans-3-methyl-2-hexonic acid. It is this substance (that you can now practice saying out loud) that causes sweat to smell bad = body odor.

We wash our armpits to remove body odor, and it works, but soap and water affects the skins acid mantle and ironically, leaves ‘the door open’ for bacteria. Sound a bit like a vicious circle? In a sense, it is.

In coming posts, we’ll be looking at the process of striking the right balance for armpit happiness.

Do Tell

Do you prefer a scented or unscented deodorant ?

PS: The book below shows you how to make 3 deodorants with simple, effective ingredients.

Make Your Own Preservative Free Natural Cosmetics With 21 Ingredients