Like many consumer products, certain salon products are best used during a particular increment of time. This interval of time is called shelf life, and it describes the period wherein a product can be used with maximum effectiveness and safety. Within this post, the average shelf life of various salon products will be discussed. First, let's turn our attention to the primary determinants of shelf life.
Factors Which Affect Product Shelf Life
1. Product Development
The formulation of high-quality hair care products is both an art and a science. As experienced hair care chemists will realize, the way a product is formulated has a profound impact upon its shelf life. Expert chemists strive to develop products that meet or exceed the market standards in terms of performance, and always with the objective of achieving product stability. Stability refers to the maintenance of products' basic character, an enduring uniformity of its blend and the preservation of a homogenous state. An unstable formulation is that many times evidenced by product 'separation', whereby the ingredients become unblended. Both environment (i.e. temperature, exposure to air, etc) may cause the product to separate. Gravity also affects a product's life in that, over time, the weightiest ingredients (such as water) will segregate towards the bottom of a mixture, as others (like oils) are relegated to the upper parts.
B. Ingredient Selection
Certain ingredients are by their nature more stable than others. For instance, animal proteins, particularly when used in high volume, are less stable than some other types of conditioning agents because of their proclivity for bacterial growth. And too, emulsifiers, used in formulas containing both oils and water, can be relatively ineffective in ensuring oil/water miscibility, (a uniform blending of these two components), over extended periods of time.
The Average Shelf Life of Salon Products
SHAMPOOS Shelf Life: 1 to 2 Years
Well-formulated cleansing and lightly conditioning shampoos have relatively long shelf lives. Detangling shampoos, however, are more difficult to stabilize from a product development standpoint because of the amount of conditioning agents utilized. The shelf life of detangling shampoos may therefore be as limited as six months to a year.
CONDITIONERS Shelf Life: 1 to 2 Years
After-shampoo conditioners will last a year or two. If the formula contains an unusually high amount of organic material such as animal protein, the life of the product may well be much less due to an increased susceptibility to bacterial growth problems.
RELAXERS Shelf Life: 1 to 1 1/2 Years (Sodium Hydroxide) 2 Years (Guanidine Hydroxide)
Of the most widely used relaxers, those formulated with sodium hydroxide are the most challenging to formulate. An improperly formulated relaxer can have a shelf life of six months or less. Well-developed formulas will work effectively for up to a year and a half. Guanidine hydroxide relaxers are a little easier to stabilize from a product development standpoint, and can be effectively used for up to two years. (If the creme portion of the relaxer system seems a bit dry on the upper surface, do not assume that the product is beyond its shelf life. This is characteristic of relaxers in this category, which contain calcium hydroxide).
HAIRDRESSINGS Shelf Life: 2 Years 100% Oils - 1 to 1 1/2 Years Cremes
The 100% oils as the hairdressing industry commonly refer to as "greases" or "pomades". They have a relatively long shelf life. Cremes, however, (i.e. oil moisturizers and creme hairdressings), are oil and water emulsions and have a shelf life of up to one and one and a half years. This is because over time, the oil will strive to the top of the emulsion, leaving the water at the bottom. Depending upon the formulation, cremes may even have a shelf life as short as six months.
FINISHING PRODUCTS Shelf Life: Up To 2 Years
Most of the products in this classification have relatively extended shelf lives. Styling Gels maintain performance integrity from one to two years, depending upon the formula. Setting Lotions, Oil Sheen Sprays, Holding Hairspray and Laminates can last for two years or more.
HAIR COLORINGS Shelf Life: 1 to 1 1/2 Years
In a similar fashion to that described for permanent wave products, the active chemicals in many hair colorings are highly sensitive to the air. With oxidization, the ability of the color product to deposit within the hair shaft is impaired. To help prevent oxidization and the resultant potency loss, many such products are packaged in single-use bottles.
Proper Product Storage
Generally, salon products should be stored at room temperature, away from heat, direct sunlight and extreme cold. Storage of products in refrigerators is not recommended and products should never be placed in a freezer. To protect products from excessive sunlight and store products near windows.
Some Tell Tale Signs of Shelf Life Expiration
The following properties will signal that a product is beyond its shelf life:
- Product Separation
- Foul Odor (likely caused by bacterial contamination)
- Loss of Product Viscosity (product becomes much thinner)
- Build up of Viscosity (product becomes much thicker)
- Rancid Odor (characteristic of natural oils that have been exposed to air and/or sunlight for extended periods)
What if a Product is Used Past its Shelf Life?
At best, a product that is beyond its shelf life will not perform as effectively as it did initially. Product application may be impaired and the way it reacts to the hair may very well be hindered. At worst, the product could cause harm to a client. In the case of an unstable or separated sodium hydroxide relaxer, the result will either be ineffective straightening or extreme causticity. This is because once a relaxer separates, the oils rise to the top and the water, containing most of the sodium hydroxide, descends to the bottom of the jar. When the stylist applies the upper portion of the mixture, the hair will be treated with the most impotent part of the relaxer. When the lower portions in the jar are used, the relaxer is much too strong and will likely damage the hair and burn the scalp. Stylists must not think that merely mixing the contents of a separated relaxer will again stabilize the formula because it won't. Relaxers must be blended at a temperature of 80 C under scientifically-controlled conditions in order to get a stable mixture.
Another instance in which a client may actually be harmed by the use of product, which is beyond its shelf life, is when bacterial growth has occurred. Should a contaminated product, wherein the preservative system has broken down, be inadvertently rinsed into a client's eyes, severe infection and/or impairment may result.
How is a Professional Cosmetologist to Know?
Other than being on the lookout for the "tell-tale" signs listed above, there is really no good way for a cosmetologist to know precisely the age of a product and its shelf life as estimated by the manufacturer. Manufacturers normally code each product so that they will know precisely when it was manufactured, and via their scientific tests, manufacturers can also predict the shelf lives of their various products. (By law, companies must also retain samples of each batch of product; which they produce for three years, in order to track the impact of product aging within a controlled environment). Should you have a specific question regarding the shelf life of a certain product, containing the manufacturer may be the best avenue to pursue.