Crafting Cosmetics IV
Weight vs Volume = Effective vs Ineffective / Safe vs Unsafe
Lately Ingredients To Die For has seen a sharp increase in customers that are formulating their cosmetics by volume, instead of by weight. After lengthy discussion with these formulators it's become apparent that they are doing this because there are suppliers posting recipes using volume giving credibility to this method of formulating. This is a dis-service to the formulator who is creating products for sale to the public. It's fine to take a recipe posted by a hobbyist and re-create it for your own use however, when you are making a product to sell to the public you have a responsibility to make sure that your product is safe and you have an obligation to make sure that it delivers you promise. You can't live up to that responsibility, or that obligation, when you measure by volume because the starting materials were never tested by volume and the results, even when accurate due to painstaking work, will not be consistent and the result will at the very least be a loss in sales when your customers get tired of getting their product different every time they order it.
Let's take a closer look at the possible problems with volume vs weight.
First and foremost, all manufacturers use weight when they run their trials. These trials are used to determine two things; the efficacy of the material and the safety of the material.
When we're considering an inconsequential material such as olive oil the parameters won't be very important.
When we're considering a material such as the preservative the parameters are very important for two reasons; first, if you have too little preservative it may not be effective at controlling microbial contamination and may result in a product that is unsafe due to a bacterial / mold / fungal contamination and skin damage… second, if you have too much preservative it will be in the final product at levels that are above the safety levels established by the trials and will result in a product that is unsafe due to skin irritation / damage or worse systemic toxicity.
When we're considering a material such as an active the parameters are as important as those of a preservative because if an active is used at a level below the efficacy level established by the trials it won't deliver the results that should be expected when using an active. These are costly materials and to use them at ineffective levels is not only a dis-service to your customer but it's a waste of money.
The above issues are serious to the success of your company but, that doesn't compare to the gravity of having the FDA determine that your product is mis-branded which could happen when using re-constituted materials or labeled actives.
For that reason alone, when considering a material such as Aloe Leaf Juice the parameters are crucial. If you are under the established parameters to re-constitute Aloe Powder to Aloe Leaf Juice and you label it as Aloe Leaf Juice, not only are you mis-leading your customer and risking damage to your company's reputation but your product will be mis-branded in terms of the FDA's labeling requirements and that will cost you much more than lost sales and customers.
The same is true if you are considering a material such as Allantoin. If you are under the established monograph of 2% by weight then your product will not qualify as a skin protectant. If you are marketing it as such it will be mis-branded in terms of the FDA's labeling guidelines.
The same would be true if you were using Salicylic Acid for acne treatment and the Salicylic Acid levels were under the established monograph of 2% by weight. Not only would it be in-effective and a dis-service to your customer but it would be mis-branded in terms of the FDA's labeling guidelines.
Now that we've seen why it's important that our cosmetic materials are used at the proper levels, let's take a look at the variable involved in measuring them by weight vs volume.
First, let's consider the ease of manufacturing.
If you're measuring by volume and we had a formula using five ingredients in just the water phase:
24 ounces water
2.5 ounces glycerin
0.5 ounces of preservative
0.2 ounces of polymer
0.3 ounces of an active
bowl that will be used to heat the water phase
the cup to measure the water and glycerin (if using one large enough for both)
the tablespoon to measure the preservative
the teaspoon and half teaspoon to measure the polymer
the teaspoon, half teaspoon, eight teaspoon and thirty second teaspoon to measure the active
That's seven utensils that you'll need to sanitize before using them and you'll need to wash after using them and that's if you use the same teaspoon and half teaspoon for the polymer and the active which will need to be sanitized in between the different materials to avoid cross contamination
If you're measuring by weight using the same formula:
bowl that will be used to heat the water phase
scale to weigh the ingredients (using the tare function in between each ingredient)
That's one utensil (the bowl) that will have to be sanitized before and washed after, and this is just the water phase.
Next, let's consider the accuracy of measurement.
If you're measuring by volume in the above formula we are using three powders that will be measured using spoons. Because they are light powders you will get different amounts each time they are measured because powders settle so, one time you may get more in your spoon and the next time you may get less. Even if you try to tap the spoon down each time you can't be sure that you've tapped each measurement down the same amount every time you make your product
The other issue is that the powder may become compressed. If you're using a powder or a wax that came from the bottom of the drum it will be compacted and heavier. One cup, which would normally hold eight ounces will now hold 12 ounces by weight while still measuring only one cup. If you're measuring by volume and that one cup was 20% it just became 30% and that's enough to de-stabilize your formula or change it from a safe product to an unsafe product. If you are measuring by weight it won't matter because the scale is measuring the weight not the volume.
Yet another issue is that all materials are different when you compare their relative weight to volume. An gallon of Vegetable Glycerin by volume is not equal to eight pounds by weight as Vegetable Glycerin is much heavier than water and that gallon of Vegetable Glycerin weights ten pounds so aside from all the additional utensils that you'll need to measure by volume you'll also have to take the time to convert everything based on their specific gravity. By the same rational some materials are much lighter than water so you would end up having less than you intended when measuring by volume vs weight
Now, let's consider the practicality of scale up.
If your product is successful you will have to increase your batch sizes. When your formula calls for 75% water and you're making one gallon that equates to 96 ounces, which is already hard to measure in volume. What about when you need to scale up and make a five gallon batch. How are you going to measure 480 ounces? There's no measuring cup big enough. At this point you'll have to convert your formula to weight which will most likely end up in a failed batch because the calculations had been off the whole time. There's nothing worse than having to write off five gallons of product.
When you're producing a product that goes on the open market you owe it to yourself and your customers to make the manufacturing process as reproduceable as possible to ensure consistent product from batch to batch. That requires you to eliminate as many possibilities for error as possible.
You also have a responsibility to deliver a safe product from batch to batch. That requires that you eliminate as many potential contamination points as possible and the fewer steps and utensils you use the better as each step and each utensil is adding an opportunity for contamination and the more opportunities there are the more likely you'll end up with a contaminated product that gets into the hands of the unsuspecting customer. This also applies to the appropriate use of preservatives and making sure that they are used at just the right amount to protect your products and not enough to create an overload.
All of us in the business of manufacturing products for sale to the public have to remember that our customer places a great deal of confidence in us and our companies every time they make the decision to buy our product. We owe them, at the very least, a true commitment to safety, efficacy and quality. With the Cosmetics Industry being an unegulated industry it falls on us to regulate ourselves and make sure that we're doing the right thing, each and every time, for the sake of our customers.
The best resource for labeling information is the FDA's Cosmetic Labeling Guide. This is very indepth and you can find the answers to any questions that you may have.
Old Will Knott Scales
The Ingredients To Die For Staff.