Customers often ask Microchem questions about the choice between natural and synthetic preservatives. Choosing whether to use natural or synthetic preservatives for cosmetics is an important decision that has many implications. It will affect product stability, odor , appearance, texture and most importantly, safety.
To help customers choose the best preservative for their products, Microchem has assembled the following list of benefits and drawbacks of natural and synthetic preservatives.
Of course, generalizations must be made in order to fit all the different types of natural and synthetic chemicals into categories. Remember that no matter which preservative a cosmetics maker chooses, they are responsible for confirming safety and stability.
Benefits of Synthetic Preservatives
- Broad-spectrum of activity against bacteria and fungi.
- Many options are available.
- Produced by established chemical manufacturing firms that understand a great deal about the chemicals.
- Consistent from batch to batch.
- Relatively low cost
- Safety/toxicity profiles well understood.
- Compatibility with other cosmetic and personal care product ingredients is well understood.
- Low concentrations required to effectively preserve products.
- Generally do not interfere with fragrance, lather, color, or other aspects of a given formulation.
- Companies that produce synthetic preservatives often have in-house microbiology testing laboratories and can offer fee-based support to cosmetics formulators.
Drawbacks of Synthetic Preservatives
- Many have developed negative reputations in popular media related to cosmetics.
- Often petroleum based.
- Some consumers find them irritating to the skin.
- Interfere with “natural” and “organic” product labeling.
- May require a narrow pH range to be effective.
Benefits of Natural Preservatives
- Allow “natural” and sometimes “organic” product labeling.
- Consumers generally prefer natural preservatives over synthetic preservatives.
- Often function over a broad pH range.
- Many confer natural fragrances to products.
Drawbacks to Natural Preservatives
- Fewer options available.
- Often do not inhibit microbial growth as well as synthetic counterparts.
- Often lack broad-spectrum activity. For example, a natural preservative may inhibit the growth of Staphylococcus aureus or “Staph” in a formulation, but may have no mold-inhibiting effect.
- May require relatively high concentrations in formulations to be effective.
- Often have undesirable impact to other aspects of formulations, such as color, fragrance, or lather.
- May result in skin sensitization (immunological reaction to the natural preservative that increases over time.
- Consistency and potency may vary considerably from batch to batch.
In summary, synthetic preservatives have been around for decades and have successfully preserved thousands of cosmetics. Lately, the market has been driven toward natural preservatives by evidence of toxicity of certain traditional synthetic preservatives. Unfortunately, selection of natural preservatives is limited, they can vary in terms of potency from manufacturer to manufacturer and batch to batch, and sometimes affect other aspects of the formulation in an undesirable way.
Regardless of whether your company chooses to use a natural cosmetic preservative or synthetic cosmetic preservative, Microchem can verify preservative effectiveness, ensuring a given formulation remains safe and stable over the course of normal usage. If you are interested in scheduling a cosmetic challenge test, simply contact the lab or request a price quote.