WHAT IS "TEARLESS"
First of all, let’s get clear that “tearless” is a descriptive term, not a measurable property of shampoos. Well, maybe it COULD be measured, but it isn’t. That would require abusing many rats or rabbits. Secondly, there is no industry standard of what makes a product “tearless.” It’s a meaningless term that is flung around indiscriminately by shampoo companies. Each company can have a different definition or use of the term.
“Tearless” is a term first used in the beauty industry to describe baby shampoos. But many of the pet shampoos that are marketed as tearless bear no resemblance to the mild formulas that have been developed for the baby market. The pet industry has simply co-opted the term. While some companies reserve the term for specific products that copy the formulation principles of human baby shampoos, others apply the term across the board to all of their line. BTW, even products sold as tearless for human babies have no standard definition, and some are more likely to irritate eyes than others.
Why are tearless products needed? Soaps and strong detergents can damage sensitive eye tissue. Getting shampoo in the eyes and having subsequent eye irritation and corneal abrasion is one of the more common mishaps in pet grooming. If not identified and attended, a dog can rub or scratch an irritated eye and cause serious damage. Some shampoo irritation can cause corneal damage even without the dog aggravating the situation.
There are several formulating options used to create shampoos with low or less potential for eye irritation. These include:
- Using non-ionic or amphoteric surfactants (not sulfates or sulfonates) as the primary cleansers.
- Adding amides or betaines as co-surfactants to reduce the irritancy of strong cleansers.
- Diluting the shampoo. Irritancy is related to the concentration of surfactants. (Using a foamer to apply shampoo dilutes it with air and makes it less likely to irritate.)
- Minimizing the amount of colorants and synthetic fragrances or avoiding them altogether.
- Avoiding cationic conditioning agents. Yes, cationics can be more irritating to eye tissue than anionic detergents.
- Adjusting the pH to be close to the pH of the eyes, 6.5-7.0.
Because the term “tearless” simply means “less likely to cause eye irritation”, some companies call their product(s) “tearless” if they have done just one of the above things. For example, if I were to use Sodium Laureth Sulfate instead of Sodium Lauryl Sulfate, my product would be less likely to cause eye irritation than one using SLS. Likewise, a product with a pH of 6.5 is less likely to cause irritation than one with a 7.5 pH, or a soap that has a 9.5 pH. Looked at this way, almost any given shampoo is less likely to cause irritation than some other (hypothetical) shampoo. While these products may technically be tearless, they are not the real deal.
Pet shampoos that are formulated specifically to be unlikely to cause eye irritation utilize more than one of the formulating options listed above. An example of this is ShowSeason Truly Tearless. The ingredients are: Water, Disodium Oleomide, aka Disodium Oleamido MEA Sulfosuccinate, Cocamide MEA, Sodium Laureth Sulfate, Sunflower Triglycerides, Aloe, Preservative (DMDM Hydantoin), pH modifier. This shampoo uses a very mild sulfosuccinate as the primary surfactant, along with Sodium LaurETH Sulfate (much milder than SLS) and an Amide (Cocamide MEA), as well as no colorants and insignificant fragrance.
There is a downside to authentic tearless formulations and that is that they are likely to be less great at removing dirt, stains, and sebum. In other words, they may not clean as well as products formulated with stronger detergents.
Shampoos that are most likely to cause eye irritation:
- Soap bars, such as Chubbs bars. (the 9.5 pH is not adjustable and causes eye irritation).
- Degreasing shampoos (Use strong detergents at high concentrations).
- Products with Sodium Lauryl Sulfate as the primary or only cleansing surfactant. (SLS is the harshest detergent and most likely to cause both eye and skin irritation.)
- Products containing d’limonene. (Although it’s a component of citrus oil, d’Limonene is extremely irritating. It can be a degreaser, an insecticide, or a fragrance component.)
- Products with heavy colorant, such as whiteners.
- Products with heavy fragrance.
- Shampoos with cationic conditioning ingredients.
The danger of indiscriminate use of the tearless claim is that it gives users a false sense of security with products that may have moderate to high potential for irritation. The truth is NO shampoo can guarantee to never cause eye irritation. Even formulas designed specifically minimal irritation can bother a sensitive individual.