Special studies on biological products
(products with enzymes)

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The 3-PAT is commonly used to evaluate irritation with repeated exposures. We compared biological and non-biological products side-by-side. Each of four laundry products was tested at 0.25%: a non-biological compact powder, a biological compact powder, a non-biological liquid and a biological liquid.

Results: The biological products did not produce more irritation than the non-biological products, confirming that the addition of enzymes to a detergent formulation does not result in an increase in the skin irritation caused byprofile of the detergent.

This type of test is based on realistic exposures to the product, and can evaluate the potential of the product to cause either irritation or sensitization (allergy). It has been described in several P&G publications (Rodriguez, et al. 1994 and Bannan, et al. 1992). The general test design is for volunteer panelists to use the test product in place of their usual laundry detergent for all home laundry.

For this test, volunteer panelists with at least one child of age 4 or less in the family were allowed to participate. Volunteer panelists were assigned to one of two groups. In phase one, one group used a biological laundry detergent in place of their normal detergent for a period of 6 weeks. The other group used a non-biological product. At the end phase one, the panelists switched product for another 6 week home use phase. Skin evaluations were conducted every 3 weeks. In addition, diagnostic patch testing was conducted at the beginning and the end of the study to detect contact sensitization (skin allergy).

Results: In our test on laundry products, 111 families participated. There were no differences in skin condition during use of product with enzyme versus product without enzymes. Furthermore, there was no evidence of contact sensitization among any panelist or family member. These results confirmed that the presence of enzymes in laundry product does not increase skin irritation, decrease mildness or cause skin allergies.

Home Usage Tests in Mexico: In Mexico, 65% of consumers perform all laundry tasks exclusively by hand. The remainder use a combination of hand and machine laundry. In addition, over 90% of consumers use the same detergent product for both hand laundry and washing dishes. Therefore, consumers in Mexico typically have much greater skin exposure to laundry products than consumers in Europe and North America.

We conducted two home usage tests in Mexico. In the first test (a two week test), a biological powder detergent was compared to a non-biological product currently on the market in Mexico. The 502 volunteer panelists used each product for 2 weeks. The condition of the panelists' skin after using each product was evaluated by a dermatologist after using each product. In addition, the panelists were asked to rate the mildness of each product.

Results: The dermatologist's evaluation indicated that the biological product was milder to skin than the non-biological product. The panelists' rating showed a similar result. Thus, the results of the two week test confirm that enzymes do not have an adverse effect on the mildness of the detergent product.

In a second home usage test (a four week test), 311 volunteer panelists compared two different biological detergent formulations.

Results: The skin evaluations gave no indication of any adverse skin effects due to either product, confirming that biological detergent formulations are mild under the extreme use conditions common in Mexico.

We conducted a three week home usage test in Venezuela where, like Mexico, hand laundry is the norm. The test compared two biological powder detergents: one had a higher level of enzyme compared to the other with different enzyme levels. The 223 volunteer panelists used each product for 3 weeks. The condition of the panelists' skin after using each product was professionally evaluated after using each product. In addition, the panelists were asked to rate the mildness of each product.

Results: There were no significant irritant or other adverse skin effects from either product, confirming that an increase in the level of enzymes does not have a deleterious effect on the mildness of the product.

In Morocco, the normal laundry practice is for consumers to mix their laundry powder with a small amount of water to make a highly concentrated slurry or paste of the product. This is applied directly to clothes by hand, resulting in skin exposure to a high concentration of the laundry product ingredients.

The total duration of the home usage in the test in Morocco was 12 weeks. For the first 6 weeks, the 142 volunteer panelists laundered clothes in a controlled test facility using a concentrated paste of a powder product containing enzymes. For the next 6 weeks, panelists used the product at home as they would normally use their regular laundry detergent. A diagnostic patch test for contact sensitization (skin allergy) was conducted prior to the start of the test, and after completion of the test. The skin condition was evaluated at the start, after the first 6 weeks and at the completion of the test.

Results: After 12 weeks of use under these extreme conditions there was no evidence of adverse skin effects either in the objective evaluation or in the panelists' comments. In addition, there was no evidence of contact sensitization (skin allergy).

References:

• Suskind, R. R., M. M. Meister, S. R. Scheen, D. J. A. Rebello. 1963. Cutaneous effects of household synthetic detergents and soaps, Archives of Dermatology, 88:117-124.
• Rodriguez C., G. Calvin, C. Lally, J. M. LaChapelle. 1994. Skin effects associated with wearing fabrics washed with commercial laundry detergents, Journal of Toxicology - Cutaneous and Ocular Toxicology, 13:39-45.
• Bannan, E. A., J. F. Griffith, T. L. Nusair, L. J. Sauers. 1992. Skin testing of laundered fabrics in the dermal safety assessment of enzyme-containing detergents, Journal of Toxicology - Cutaneous and Ocular Toxicology, 11:327-339.