[ozgirl]

@Max From the Abstract for that article it looks like they were using 2.5% essential oil compared to 0.4% methyl paraben. So the comparison isn’t really equal.

It is unlikely that any of the essential oils they tested would be used in a product for skin contact at that level due to the odour. Not to mention the cost and skin compatibility. There are definite limitations to using them as preservatives.

[ozgirl]

The NaOH is an 18% solution so the amounts are not really comparable.

The main factor that will need to be considered is cost (& availability).

If you are targeting a niche market then your marketing team might have a preference in terms of customer acceptance.

[ozgirl]

How did you determine your 6 month expiry date?

To determine an expiry date you will need to conduct stability testing on your product.

Perry has written about how to do this on his blog https://chemistscorner.com/how-to-stability-test-a-cosmetic-formula/

[ozgirl]

This document should give you the information you need.

http://www.in-cosmetics.com/__novadocuments/5122

[ozgirl]

Have you considered Benzyl Alcohol and Dehydroacetic Acid (Geogard 221) which is ecocert approved.

I have read about lots of problems with the Leucidal products.

Which ever option you choose you will need to do a preservative efficacy test to ensure it works for your formula.

[ozgirl]

I don’t the restriction has come into effect yet.

[ozgirl]

You will need to add a preservative and then perform a product stability test. You can perform accelerated product stability tests at higher temperatures to get an indication of shelf life.

Isothiazolinone preservatives are often used in dishwashing liquids. Ask your suppliers what they recommend based on your product type and pH.

All of your ingredients have long shelf lives but once you mix them together it doesn’t matter because they have been diluted.

[ozgirl]

This is not a good starting formula for a dishwashing liquid.

Try searching for Stepan formulations as a much better starting point.

https://www.stepan.com/Products/Stepan-Prototype-Formulations.aspx

[ozgirl]

What is the pH of your product? PET bottles do not like high pH.

As others have suggested it is probably the essential oils / fragrance combined with poor quality bottles.

[ozgirl]

Do they just want you to use BTMS as your emulsifier? It is often used to create a drier feeling cream.

I’m not sure if there are any other benefits.

[ozgirl]

It is possible the alcohol in the Witch Hazel extract is helping to solubilise small amounts of oil soluble ingredients. Just because the ingredients are in the list does not mean they are present in any significant amount. They could be there but at less than 0.1%.

[ozgirl]

As Belassi said it sounds like normal behaviour from a pearlizer. Do you have any photos?

[ozgirl]

I do love to read a good bit of scaremongering fiction in the morning! 

The author of that article doesn’t even know if they are against petroleum or petrolatum. They sound similar so they must be the same.

You can learn more at

http://www.cosmeticsinfo.org/ingredient/petrolatum-0

[ozgirl]

Sounds like an incompatibility between cationic and anionic raw materials. What is your gelling agent? Carbopol polymers are anionic.

[ozgirl]

It is possible that you are experiencing “pilling” with your cream.

[ozgirl]

I have used the Geogard 221 preservative in a couple of o/w emulsion products and only found a slight discolouration over the shelf life of our products (2 years). Just be sure to keep your pH below 6. 

[ozgirl]

Also what type of product is this? I am guessing it is a cleaner or disinfectant type product. There are many different types of thickeners available but which ones would be suitable and cost effective would depend on the type of product.

You could try reducing the amount of fragrance.

[ozgirl]

They have sent you the brass bushing rather than the PVDF bushing. The brass bushing is cheaper than the PVDF bushing (see bottom of this website https://www.scilogex.com/scilogex-d500-homogenizer.html).

Contact your supplier and get them to send you the correct part.

[ozgirl]

Thanks. I think you might be right. It is often the simplest answer.

@Belassi - Love the Brawndo reference

[ozgirl]

Some fragrances and some preservatives are known to thin emulsions. Try a knock out experiment to see if this problem is caused by one of your raw materials.

[ozgirl]

I like Australian Scientific (not in Perth but they ship) (https://www.austscientific.com.au/).

I have also received lots of marketing information for labfriend.com.au but haven’t used them as yet.

[ozgirl]

There seem to be a lot of ingredients in this formula that are not usually used in shampoos.

Why do you have cetyl alcohol, shea butter, stearic acid and dimethicone in your formula? These ingredients are best used in your conditioner and may be detrimental to the performance of your shampoo.

[ozgirl]

I would also remove the boric acid as this will also react with the sodium bicarbonate. It is more common to use sodium carbonate in floor cleaners rather than sodium bicarbonate.

I would recommend joining the UL Prospector website and searching for books called Advanced Cleaning Product Formulations by Ernest W Flick for good starting formulations.

When you create a formula you need to know what the function of each raw material is and if it will interact the raw materials in the formula.

If you are planning on putting this into commercial production I would suggest contacting a consultant or discussing with your manufacturer.

[ozgirl]

The lab scale stability test usually gives a good indication that the product should be stable when made at a production scale but it is certainly not a guarantee. As @DAS mentioned there are many things that can go wrong when scaling up from lab size samples to production size. 

[ozgirl]

All this formula will give you is a “volcano” when the acetic acid reacts with the sodium bicarbonate.

I suggest looking for a better starting formulation. Do you have access to UL Prospector?