During the monthly review of particulate levels with a BACS cleanroom client, the quality manager observed a spike which occurred every day in the afternoon. Upon investigation, it was discovered that a small number of employees were applying make-up before meeting people during their lunch breaks. The cosmetics were not being fully removed prior to re-entering the cleanroom, resulting in noticeable particulate increases. Creams, lotions and cosmetics worn by people who work in a cleanroom can pose significant threats to cleanliness levels. Compared with microelectronics manufacturing which generally has a greater sensitivity to particulates, pharmaceutical production is much more affected by microbiological impurities. Cosmetic particles not only are made up of contaminating chemicals, they could also compromise the sterility of a cleanroom.
The first comprehensive study of these dangers appeared in an article entitled “Cosmetics in Clean Rooms” from the 1984 proceedings of the Institute of Environmental Sciences. Researchers measured particle levels generated by cleanroom staff who wore make-up while manufacturing IBM disk drives in San Jose, California. Cosmetics were grouped into categories such as lipstick, blush, powder, eye shadow and mascara. Tests showed 15 different chemical elements were present in the make-up, with 48 ingredients specified on the product labels. A cosmetologist helped researchers determine what constituted an average amount of each cosmetic used on a face. The number of particles 0.5 micron and larger per typical application ranged from 82 million for eye shadow to 3 billion for mascara, with the total particle count around 5.1 billion per average face of full make-up.
The study also included looking at particle transfer rates. When air current testing was done at velocities of less than 0.3 m/s (below the typical airflow found in most cleanrooms), blush, powder and eye shadow all transferred in moderate to heavy amounts. A touch test was designed where a person donned fresh gloves, then very lightly touched the cheekbone of a person wearing typical amounts of make-up. This touch was barely perceptible to the recipient and was much lighter than the force used to scratch an itch. The gloves were then placed in contact with a contamination-sensitive surface. Eye shadow transferred in moderately heavy amounts and lipstick, blush, powder and mascara all transferred in very heavy amounts.
Results from this study were so conclusive that no major subsequent testing was conducted. As a consequence, cleanrooms banned the use of cosmetics. One exception to the “no cosmetics” rule is skin lotion. While they are a potential contaminant, certain skin care products are very useful in reducing the amount of dry skin that sloughs off. These skin flakes could carry bacteria as well as increase particulate levels and bioburden in the cleanroom. Here are three things you can do to benefit your cleanroom:
- Provide cleanroom users with cleanroom-approved moisturisers that are free from fragrances, dyes, petroleum, silicones, lanolins, mineral oils and glycerins.
- Avoid, if possible, products which contain alcohol and other ingredients that could dry the skin and produce additional flakes.
- Most importantly, create a culture where people willingly forgo wearing cosmetics that could impact the safety and integrity of products being manufactured in the cleanroom.