Hello and welcome

to our preservatives lesson,
where we are going to talk about

preservation in general,
scenarios when we don't need to

use preservatives, and of course,
we are going to discuss the SCRUB method.

Okay, so first, let's
clarify why we need to use preservatives.

Well, it's very simple.

Simply because we want safe products

that are protected
throughout their shelf life.

So I'm talking all the way
from raw ingredient.

To an empty jar.

Your preservation system
needs to work all the time.

I listed a few scenarios where contamination

can happen, and I hope
by you knowing these, you can avoid them.

You can avoid these things happening.

So first up, by the way,
this list is not in any particular order.

So first up is poor manufacturing
practices or processes.

By this, I mean,
it might be that you didn't disinfect your

beaker properly, or there
can be cross-contamination,

because you use the same spoon for product
A and for product B.

Always use separate spoons.

Or it can happen that your raw
ingredient was already contaminated.

These things happen.

Okay, just be aware.

Another contamination opportunity is the environment.

Imagine I buy a face cream,

I'll keep it in my bathroom,
where it's warm and very humid.

This is actually a perfect
breeding ground for microbes.

So the environment can create scenarios
where contamination can happen.

The water content of the product.

Any product with water
will need preservatives.

Okay?

That's why quite often new formulators
start by creating lipid only product or

anhydrous products such as face oils,
or lip balms, or even powdered masks,

because those have no water, therefore
they can forget about preservation.

Contamination can also happen at the consumer.

So if your product arrives

at the consumer, you don't know
how they're going to use it.

Let's just say it can happen that they

forget to wash their hands before
they dip their fingers into the jar.

So that can b possible contamination,
but your preservation system needs to work against this.

Next up is challenging ingredients.

That means the very nature of natural
ingredients would mean that these

ingredients are full of plant materials,
full of plant matter, nutrients,

minerals that are, again,
excellent for microbes.

So just by the very nature of natural
skincare means we use

a bit more challenging ingredients
compared to synthetic ingredients.

And next is the shelf life.

By this I mean a good shelf-life

life would also mean good
preservation system.

So if, let's just say you have a good product

that you tested, you stability
tested, we'll talk about this later,
and the stability test would give you a shelf-life of 2 years,
shelf life of two years,

but your preservation system doesn't, that
means it cancels out every other test.

So the preservation test is a stability test, and if you fail that,
you fail everything else.

So that's why we always check the preservative system first,
and then we move on to checking

how the product behaves in heat
or in cold or in light.

But if, the challenge test
or the preservation test is a fail,

it cancels everything else out.

Okay, so there are a few scenarios when we

don't need to use preservatives,
and I listed them here.

These scenarios don't happen all the time.

There are some instances where they are used.

But we don't cover many of these in this

lesson simply because
they are not that common.

The first is no water content,
and I mentioned this before,

so completely anhydrous product would have
no water content,

your lip balm, your face oil,
but we don't cover this in this lesson.

If your product has low water activity.

This doesn't mean the water content in the product,

it would mean the available water in
the product that has to be under 0.6.

In layman's terms, think 5 %.

So if your product has less than 5 % water,

and that includes water-soluble extracts,

then you may be able to skip
using preservatives.

If you are unsure, a safety assessor can help you with that.

They can check your formula and tell you,

Okay, we need to add or we don't
need to add preservatives.

Another scenario would be if your product

has a minimum 20 % ethanol content,
and that's the overall ethanol content,

not an extract with this
much ethanol content.

A simple example would be a hand sanitizer, but that would have much
more than 20 % ethanol in it.

If we were to create,

let's just say a face tonic with this
much ethanol, it would be very drying.

It doesn't happen a lot,

but it can happen, especially if drying
of the skin is the point of the product.

But it's not very typical.

Another scenario would be a glycerin or

a humectant content where it
has to be a minimum of 40 %.

Again, doesn't happen a lot simply because

this much glycerin in a product would be
extremely unpleasant to use.

It's very sticky.

And finally, we've got extreme pH,
where the product is under.

Ph 3 or over pH 10.

An example would be a chemical peel that
would be under pH 3, so extremely acidic.

But as you know, that is usually used
and applied by a professional.

And the high pH product would be

a hair removal cream,
which normally has a pH of 11.

So we don't cover these products in the
course, but I wanted you to be aware

that certain scenarios
would mean you can skip using preservatives.

And finally, let's check
out the SCRUB method.

Okay, so in the past few years, I worked on various

projects where I had to use all sorts

of preservatives in very
different conditions.

And often I felt completely lost.

I just didn't really
know how to approach it.

Obviously, I know what to do and
what to look for, but by creating this method

helped me tremendously to always remember
what I need to check when I select a
preservative.

So the SCRUB method is
basically an acronym.

I took the first letter of five different

words and that created the word SCRUB,
and I felt that was easy to remember.

So here we go S for Solubility,
C for Contraindication,

R for Range, and that means pH range,
U for Usage, and B, if your
preservative is broad-spectrum or not.

So let's take the SCRUB
method apart a little bit.

First, we check the solubility
of the preservative.

If the preservative is not completely

water soluble, you will probably
need to use a solubiliser.

What happens is that most preservatives,

to create the broad-spectrum effect,
will have various components.

And if one component, even if just one,

is not water-soluble,
you will probably need to use

a solubiliser,
or that one component will just float

on the top of your product,
and it can be dangerous because

it's a concentrated area
and it will not be effective.

This is most important when you create

a product that is completely water-based,
such as a face tonic or a face gel.

Contraindications.

Now, here I listed salicylic acid.

This is a classic example.

So if the preservative has salicylic acid
component, it cannot be used in any

product designed for children
or for babies for that matter.

So this is a legal issue,
you just cannot use it.

The information is given to you

by the supplier, so always check what the
supplier says about that preservative.

Next up is pH range.

Most of the time,

preservatives work within
quite a wide range of pH,

such as between 3 and 8,
which is perfectly okay,

because normally when we create products,
we are within those limits.

But sometimes there are preservatives
that have a very,

very narrow pH range they work within,
such as Dermosoft 1388.

The recommended pH range should be between

really give you much room for error.

You need to check that,
because if you create a product where you

need, let's just say,
an eye cream where pH 6 would be better,

then probably this preservative is not
suitable for that particular product.

Then you check the usage.

It's a misconception that every

preservative should be added
to the product at 1 %.

That's incorrect.

Every preservative will have very

different limits
of use to make them effective.

For example, again here, I gave you Dermsoft 1388, which is normally 2-4,

I tend to use it within 3 and 4 %
or Geoguard ECT, which is 0.6 to 1 %.

What is important here is that you
don't go over these limits.

They are quite often legal requirements.

And finally, check that your
preservative is broad-spectrum.

A preservative should protect the product
from bacteria, yeast, and mould.

If your preservative is not effective

against all these three, then your
preservative is not broad spectrum.

This means you will need to have

an additional preservative
with that chosen one.

So in this case, don't Dermsoft 1388 is excellent against bacteria,

but is not so effective
against yeast and mould.

So in this case, you will need to pair it

with another preservative to create that
overall broad-spectrum coverage.

And finally, let's talk about
how we use preservatives.

First, use the SCRUB method.

So now you know what SCRUB method is,

you know these 5 criteria,
you must check when you select them.

Or alternatively, I've given you
the Bluebook of Preservatives.

In the blue book, I gave you information
about, I think,

that can be used in natural skincare.

If you are unsure,

please send me a message and I'll
check it for you or I'll tell you.

So use the SCRUB method
to pick your preservative.

Always follow the recommended amount.

I cannot emphasise this enough.

I mentioned this before,
use the limits provided by the supplier.

If you are unsure when to add

the preservative, keep the preservative
to the end of the formulation.

Normally, we add it at the end.

Sometimes we can add it in the beginning,

depending on the formula or
in the middle of the formulation.

But if you are unsure, the best
thing to do is just keep it to the end.

That is a very normal practice.

Some preservatives are heat-sensitive

anyway, some aren't,
but again, if you are unsure, add it at the end.

And finally, check the pH
and adjust the pH if you need to.

Now,
we tend to check the pH and adjust it

at the very end, again,
after adding the preservative.

However, let me just go back.

Sometimes your preservative
has a very narrow pH range.

So here you see with Dermosoft.

In this case,

when you've got such a narrow range
to work within,

check the pH first, adjust it,
add the preservative, and check it again.

So check before and after
adding the preservative.

If your preservative has
a very narrow working pH range.

Okay, I hope this helps.

So now you understand what preservatives

are and what they protect against,
and also the SCRUB method.

We are going to look at the practical

aspect of it all when we start
to formulate products in Module 2.

I shall see you soon.