Microbiological Quality Control of Cosmetic Products6
Microbiological Limits for Cosmetic Products7
Cosmetics Risk Substances8
The Paraben8
Replacing Parabens9
ISO Standard for the Cosmetic Industry9
Cosmetics Directive Regulation11
Revolution in Cosmetic and Skin Care Industry11
Cosmetovigilance13
Microbiologist's Career Feature14
Career of Microbiologists in Cosmetic Industry15
Activity description15
Qualification15
Job duties16
Education16
Characteristics of staff16
Conclusion17
Works Cited20
Role of Microbiology in Cosmetic Industry
Introduction
The world of Cosmetics has been and is one of the fastest growing businesses throughout the world, earning an income of billions of dollars per year. Our global investment in appearance totals over two-hundred billion dollars a year. We will discover the underlying reality of cosmetics, and go skin deep into the health risks associated with beauty products down to the cell and also discuss different organisms and chemicals that are used in the development of cosmetics, and are also associated with health risks and also the beneficial factors of cosmetics. We will also discuss some of the benefit and disadvantages of seeking treatments for skin associated with Pharmaceutical companies in developing products. At almost any cost the average individual is willing to do whatever it takes in order to change their appearance, even if it means changing their skin color; either to be become lighter or darker, making their noses pointier, higher cheek bones, and fewer wrinkles (Foster, 97).
No wonder why these investments in cosmetics yield high rates of cash. This is where most of the health risks are involved. In tanning individuals have the risk of getting skin cancer, individuals that bleach their skin can suffer from hyper pigmentation and DNA mutations, and under surgical procedures an individual's lives are at stake and open to infection. The effect these products on skin have a range risks and associated diseases. Microbiological characteristics depend on the study of product preservative system through challenge testing conducted prior to and / or after the period accelerated study. For a microbiologist requires accuracy, attention, patience and perseverance. All this is useful for his work in laboratories, research activities. Usually, microbiologists are considered as diligent and disciplined professionals, but if they are busy working in the field of soil microbiology or geology, then a specialist should be unpretentious, knowledgeable and possess managerial skills.
Inside our skin
Our skin has different modes of transmission that allow for natural ways to cleanse the skin, cool down the body and also rejuvenate old looking skin. One of the coolest ways our body maintains healthy skin is by shedding dead skin cells and allowing for multiplication and division of cells on the outer surface of the skin, which is called the epidermis. Every twenty-eight days, we get an entirely new epidermis, from top to bottom! A pool of non-dividing cells is always at rest in the basement layers of the epidermis ready to take over the function of covering the body should they be needed.
Concept of Beauty
The effects of stress on the skin are very apparent on some individuals because although stress is internal, it not only has internal effects on the body but it also has external effects on the body. Stress can cause a number of external flaws on the skin such as wrinkles, blemishes, dark circles around the eyes and the appearance of aging skin. The foundation of beautiful; healthy skin begins internally, with good mental health and nutrition. Skin protection, avoidance of the sun and knowledge and prevention of use of harsh skin care products are also useful tips. There are skin products that cause blemishes and even create an environment for organisms. Make-up is useful in covering blemishes and creating the illusion of perfect skin, however good make-up is also a great place for bacteria to create a habitat. Many people do not realize that any cosmetic product that is good for your skin is also a good breeding ground for microorganisms, bacteria, and fungus.
Defining Cosmetics and Skin Care Products
Cosmetics, toiletries and perfumes are preparations consisting of natural or synthetic substances for external use in various parts of the human body, skin, hair, nails, lips, external genitalia, teeth and mucous membranes of the oral cavity, aimed exclusively or mainly to cleaning them, perfuming them, changing their appearance and / or correcting body odors and / or protecting them or keeping them in good condition (Luckiesh, 23).
According to the definition afforded by the legislation, the Cosmetics, Health and Beauty Products are preparations consisting of substances natural or synthetic, for external use in various parts of the human body Skin, hair, nails, lips, external genitalia, teeth and mucous membranes of the oral cavity, aimed exclusively or mainly to cleaning them, perfuming them, changing their appearance and / or correcting body odors and / or protecting them or keep them in good shape (Koller, 256).
Role of Microorganisms
In our daily life we catch millions of microorganisms, but because of our immunity and immune system we are able to fight off infections, some diseases, and create a defense and protection mechanism for our bodies. If not for our versatile; detective; complex immune systems none of us could live long past infancy (AM, 36). In cosmetic microbiology there is called "Phoenix Phenomenon", which some authors believe is related to the low sensitivity of our microbiological methods of traditionally detecting microorganisms present in cosmetics, the high content of preservatives (antimicrobials) that carries the sample analyzed and others ability to adaptation of certain bacterial species. Pimples that form on our skin are one of the enemies that the body fights off but sometimes the battle is not as successful as we would like.
Knowledge of the microorganisms that affect our body's positively or negatively is necessary in finding a solution for our skin problems (Orth, 332). Our skin is a habitat for some of the organisms that we acquire, which are commonly called skin flora or normal flora. Detaining the company should be responsible for evaluating the stability of their products before making them available to the consumer, a fundamental requirement for quality and safety of themselves. Products on display for consumption and to present stability problems organoleptic, physico-chemical and / or micro- biological, in addition to breaching the technical quality requirements can be placed at risk the health of consumers by setting sanitary infraction. Cosmetic products susceptible to contamination are those that water present in the formulation as emulsions, gels, suspensions or solutions. The use of suitable preservatives and validated systems and test preservative system challenge through Challenge Test, and compliance of Good Manufacturing Practices are necessary for the preservation appropriate formulations (Yablonski, 40).
A lot of the times our skins natural ability to fight against harmful agents that attack the skin lies in our innate immunity. Innate immunity is your body's natural defense to fight off disease and infection, and to protect your body as a whole. It is accumulated from our parental genes. Because innate immunity is acquired from parental genes, some individuals' mode of natural defense can vary and it can also be apparent in different ways. Some people have blemish free faces while others are battling in that good old fight with Acne. Acne can be caused by a number of different organisms, but one of the most common acne causing organisms are Propionibacterium Acnes and Staphylococcus Aureus. Both of these attack the body in similar but slightly different ways. In order to ensure the quality and hygiene of the products, microbiology includes a general or specific quantitative evaluation on the basis of selected indicators. On the specific variety of pathogens are sought. The focus is on potentially pathogenic microorganisms on the skin.
Propionibacterium Acnes
Propionibacterium acnes is an organism that destroys and degrades the skins natural healing substances and oils that keep the skin healthy by creating enzymes to break them down. P. acnes can elicit an immune response that triggers the immune system (Kabara, 183). Usually when the immune system is triggered, the body responds as if it is being attacked by a foreign molecule (antigen) and sends specific response to the body so that the element can be destroyed. “The genome of the bacterium has been sequenced and a study has shown several genes that can generate enzymes for degrading skin and proteins that may be immunogenic (activate the immune system). Interestingly P. acnes are a part of our skins natural flora. This bacterium is largely commensally and part of the skin flora present on most healthy adult human skin. Our immune systems are not the only way our skin and bodies are protected; there are naturally occurring cleansers on our bodies.
Staphylococcus Aureus
Staphylococcus aureus is also part of the human normal flora of the skin and it is also an opportunist who takes advantage. Staphylococcus aureus is responsible for causing the common disease folliclitis which is a skin infection caused by the bacteria entering an open space of the skin and overtaking the hair follicle, causing an infection which can produce a pimple like bump on the skin (DS Orth, 46). This is usually caused by shaving and the bacteria can also take advantage if the skin has somehow been opened due to an allergic reaction of a diverse amount of cosmetics. S.Aureus can especially act as an opportunist on an individual that where's make-up daily and is not very critical about cleaning make-up appliances. With this type of problem S. aureus acts as an opportunist, depending on where the makeup is applied, this bacterium can affect your face in a number of ways. With eyeliners and eye shadows, a perfect environment is created directly underneath the eyelid, which can cause sty's (hordeolum). The bacterium Staphylococcus aureus that is frequently found on the skin is responsible for 90%-95% of cases of sties.
Microbiological Quality Control of Cosmetic Products
Today, the pharmacist is the professional responsible for the production of quality cosmetics, safe and effective and to achieve this objective microbiological control is considered of great importance (Hafeez, 313). Since these products can present the necessary conditions for the growth of microorganisms capable of damaging the product or, worse, affect the health of consumers. Usually, microbiologists are considered as diligent and disciplined professionals, but if they are busy working in the field of soil microbiology or geology, then a specialist should be unpretentious, knowledgeable and possess managerial skills. This is important when participating in the possible long-term expeditions.
Makeup makes us more attractive, helping to preserve freshness and maintain purity, as well as look and feel younger and more beautiful. However, shampoo, lipstick, creams and other cosmetics can cause adverse reactions and even the risk of infection, leading to infections and severe allergic reactions. ISO is contributing to the solution of this problem through an international standard that will help manufacturers of cosmetics to determine what levels and types of pollution can be harmful and which ones are safe. Microbiological characteristics must be preserved microbiological accordance with specified requirements. Compliance with good practice manufacturing and preservative systems used in the formulation can guarantee quality microbiological characteristics (Orth, 323). These microbiological characteristic is the study of the product preservative system through challenge testing conducted prior to and / or after the period accelerated study. Microbiological evaluation is important to verify whether the choice of preservative system is adequate, or whether the incidence of interactions between components of the formulation may affect the effectiveness. Physical must be preserved as original physical properties as- respect, color, odor, consistency, among others; Chemicals: they must be kept within the limits specified for the integrity of the chemical structure, content and other ingredients parameters; Microbiological characteristics must be preserved microbiological accordance with specified requirements. Compliance with good practice in manufacturing and preservative systems used in the formulation can guarantee these characteristics.
Microbiological Limits for Cosmetic Products
We must take into account criteria such as product use, route of administration and target population when establishing microbiological guidelines for safety and efficacy. Since the "cosmetic products" are not sterile products are subject to microbial contamination from the environment, raw materials, and components (Faergemann, 326). Formulations that can withstand mo or are susceptible to microbial contamination must contain preservatives to retard microbial growth. The validity period - characterized as the period of life, during which the product maintains its original features - before becoming a legal requirement, is a technical requirement of quality as an unstable product from the standpoint of physical-chemical microbiological or toxicological, besides the loss of efficacy may also cause damage and compromise the reliability of consumer.
It is recommended that the equipment used in the manufacturing of cosmetics should be designed for easy cleaning and sanitation, as well as implementing good manufacturing practices to prevent human injury or environmental microbial contamination during manufacture.
It is the responsibility of manufacturers to ensure that:
No more this is able to grow in the product
The species and number of organisms do not pose a danger to consumers when using the product as directed.
No more this should affect the stability of the product.
The product, packaging and integrity of the enclosure should be safe.
Cosmetics Risk Substances
The Paraben
In nature the parabens found in some fruits or vegetables, but when we speak of Parabens in comets or drugs are rarely naturally but syntheses, the most common being methylparaben, the ethylparaben, propylparaben and butylparaben. Parabens are controversial preservatives (Kallings, 40). However, initially they appeared to replace other preservatives like formaldehydes considered dangerous and whose use is now limited to nail polish.
Parabens have a very low toxicity and are well tolerated; however, allergies may still occur like urticaria, dermatitis, but parabens are metabolized, that is to say, the fact that you can find them in the body can be considered as worrying. Esters of p-hydroxybenzoic acid (esters of methyl, ethyl, propyl, butyl or benzyl) or parabens are used as preservatives in cosmetics and skincare products since the year 1096.
Several studies in vitro and in vivo have shown that parabens exerted a weak estrogenic activity A recent study suggests the accumulation of parabens in breast tissue cancer. The researcher hypothesizes a relationship between the presence of parabens in breast tissue, their estrogenic activity and induction of breast cancer. The potential accumulation of parabens in breast tissue, related to the use of products containing parabens, and the possible involvement of parabens in the occurrence of breast cancer should not be overlooked.
Replacing Parabens
AFSSAPS (2009) conducted a survey of market surveillance; cosmetics labeled BIO and claiming to be the absence of preservatives or some of them like parabens (para-hydroxybenzoic acid esters) or phenoxyethanol, were initiated in 2008.
On the occasion of the 2008 survey, the laboratory of AFSSAPS conducted the analysis of 28 cosmetic "organic" collected by the inspection services of AFSSAPS. The conclusion of the investigation was that, in terms of microbiological quality, the survey results are satisfactory.
However, Paraben is not the only ingredient 'at risk' found in most cosmetics market. Many ads will begin running with the slogan "PARABEN" but make no mistake that removing this ingredient does not make the product more "acceptable". Many other ingredients are also used in traditional cosmetics, which can be more "dangerous”.
ISO Standard for the Cosmetic Industry
ISO 29621:2010 Cosmetics Microbiology Guide is designed for supervisors to the cosmetic industry. It helps to identify the products with low microbiological risk.
There are many options for cosmetic product contamination by microorganisms. The new standard ISO 29621:2010 Cosmetics Microbiology Guide is designed to assess risk and determine the production of low microbiological risk. It can help you determine which cosmetic products have a low risk to users that is likely to be infected when they are used in extremely low quantity. This takes into account a number of product characteristics, such as composition, terms of manufacture, packaging, and the cumulative effect of these factors.
ISO 29 621 will help manufacturers of cosmetics and regulators to understand when you do not need to apply a routine microbiological international standards for cosmetics and other similar methods, and in some cases they are needed. The standard can be used by both public and private laboratories working to ensure production of safe cosmetic products for consumers.
The ISO offers the cosmetic industry and regulators new tools to identify products with a low level of microbiological risk. Shampoo, lipstick, face cream - all these cosmetics can help maintain the freshness and purity, as well as feel younger and more beautiful. However, they can also carry the risk of infection.
The new standard ISO 29 621: 2010 Make-up Microbiology Guidance on risk assessment and identification of products with low microbiological risk "to help the cosmetic industry to determine what levels and types of pollution are dangerous to health and which products do not bear such risks. According to ISO 29 621 the presence of microbiological risk is assessed in the study of the products, the conditions of production, packaging, as well as combinations of these factors. Cosmetics that will be defined as "low risk" do not require a course of microbiological testing. The ISO 29 621: 2010 prepared by Technical Committee ISO / TC 217 "Cosmetics" for detection and identification of microorganisms in cosmetic products. The standard can be used by both public and private laboratories that provide a safe cosmetic product to consumers.
Cosmetics Directive Regulation
Cosmetics Directive includes the microbiological product safety. According to the specific products, requirements for microbiological purity and stability are sufficient so that it while the application is not for the user to a hazardous contamination of the product (Wolven, 19). These are all influencing parameters such as packaging considered for use and storage conditions. The fulfillment of such requirements by appropriate investigations and statements is to show the central and recognized test for determining an adequate microbiological Product stability is the preservative stress test - without, however, a methodically binding test is given. It can be assumed that products in the context of the above Test systems are checked and safety evaluations were subjected to professionally accepted view that adequate securities even during the time of product use.
In 7th Amendment of the Cosmetics Directive Regulation is an additional requirement includes Date-to-use consumer information of cosmetic products with a shelf life of more than 30 months have to be provided with a period of time (Todar, 42). From a microbiological point of view, this appears as not only required because of the Safety evaluation without setting a time limit - handled as before - no fundamental risk has revealed. The understanding of the safety assessment according to the microbiological stability and purity should be about anyway foreseeable period of use can be ensured.
Revolution in Cosmetic and Skin Care Industry
The perception of the ideal individual presented by our own cultural beliefs has a big impact on an individual's perception of what true beauty is. Does this factor have anything to do with cosmetics? In fact it does. This is why the new revolution of skincare products has progressed every year. Skin rejuvenation creams, eye creams, bleaching creams, false tanning creams and sprays, chemicals, make-up, skin peels, and more can be made in a variety of different ways and are readily accessible at drugstores, convenience stores and other local vendors or even oversees via internet (USFDA, 69). Some make-up and skin creams are made of generic chemicals, synthesized to aid in mass production to fit the needs of the buyers all over the globe.
In tanning individuals have the risk of getting skin cancer, individuals that bleach their skin can suffer from hyper pigmentation and DNA mutations, and under surgical procedures an individual's lives are at stake and open to infection. The effect these products on skin have a range risks and associated diseases. Microbiological characteristics depend on the study of product preservative system through challenge testing conducted prior to and / or after the period accelerated study
Good Manufacturing Practices for Cosmetics (GMP)
MPs are the practical development of the concept of quality assurance through the description of the activities of the production unit based on sound scientific judgments and the risk assessments (Pollack, 23-27). They ensure that products are manufactured, packaged, controlled and stored according to appropriate measures to use and specificity. They exist in different sectors. For cosmetics, GMP is a set of organizational and practical advice for ensure compliance of the product, including control of human, technical and Administrative. They aim in particular the criteria of hygiene and product safety Cosmetics.
The benefits of GMP on cosmetics:
Facilitate the organization and carrying out the activities of an institution cosmetics, so control factors that may affect the quality of cosmetics.
Take into account the specific needs of the cosmetic sector.
Reduce the risk of confusion, omissions, damage, contamination, mistakes.
Involve staff through a better understanding of the activities.
Guarantee the consumer a cosmetic product of specified quality.
Having an internationally recognized repository in when exporting and importing.
Cosmetovigilance
The Cosmetovigilance is a system for monitoring and recording of adverse events associated with the use of cosmetics, allowing them to identify and centralize information about them in order to better prevent them. Established by the AFSSAPS in 2004, this system includes:
The reporting of all adverse events and the collection of information about them
The registration, evaluation and exploitation of information about these effects in order to prevent
The completion of all studies and all work on the safe use of cosmetics
The implementation and monitoring of corrective actions, if necessary
All health professionals have an obligation to report the side effects they see on their patients promptly to the Director General of AFSSAPS. Each consumer may also report side effects he is the victim, directly to the AFSSAPS through a declaration form available at the Agency. The Cosmetovigilance system was developed and implemented for the first time in France, now known equally in some European countries, including Sweden, Norway or Germany. It will soon be widespread throughout the Community, through the provisions of the new regulations governing cosmetics come into force in 2013. In 2011, the FDA has established an American equivalent system to collect, including consumer, information on adverse events associated with the use of cosmetics in the United States. Cosmetic products must be produced, stored, transported and distributed safely, and must comply with Resolution 481/99.
The presence of water and organic components in the formulation supports the growth of microorganisms. In some cases, they affect the structure of preservatives influencing product stability justifying the microbiological evaluation of the product (Barnett, 63). With the development of Good Manufacturing Practices, it is understood that the microbiological quality of a cosmetic should not rely solely on the preservative system. However, as you cannot do without their use, the choice of preservatives should be adequate to be effective. Furthermore, it should consider that preservatives can be disabled in whole or in part, leaving the product without the protection expected. Therefore, evidence of effectiveness for the preservative must be an essential part of the safety data. The study of the stability of cosmetic products provides information indicate the degree of relative stability of a product in various conditions which can be subject from its manufacture to its expiration. This stability is relative; it varies over time and depending on factors accelerates or slows changes in the parameters of the product. However, changes within certain limits cannot set up as a reason for failing the product.
Microbiologist's Career Feature
This specialist can achieve professional success, both in education and in medicine. Microbiologist can climb the administrative ladder and become, for example, the head of the laboratory, the department or a senior microbiologist, head of the department of biological and technological control.
Career of Microbiologists in Cosmetic Industry
Microbiologists who work in the cosmetic industry analyze and make the right decisions and be aware of the need for sensitive methods specific for detection of B. Cepacia and implement routine analysis to minimize risks of cross contamination by the bacterial complex. The microbiological stability is a crucial quality criterion for cosmetic products.
Microbiologist studies the microorganisms that cause various diseases in humans and animals.
Activity description
To become a professional microbiologist requires knowledge of laboratory equipment and instruments, mikrobiopreparatov and pharmacology. A microbiologist cannot do without the rules of operation of technological means and standard material for the application of microbiological protection of wildlife and cultural fabric. These skills are important for professional quality work. His work is needed in the pharmaceutical or food industry, cosmetic and skin care industry as well as medical and educational institutions.
Qualification
Professional studies; specialized knowledge and skills, knowledge of drugs, and reagents. Personality traits include communication, observation, and responsibility.
Job duties
All work is focused on micro-organisms, microbiologists and their metabolic products. Therefore he is engaged in the production of medicines and vitamins, bacterial and viral agents. He is responsible for ensuring standards of micro-organisms and their life on the nutrient media in the laboratory. A specialist is engaged in developing new techniques, laboratory testing, and testing of raw materials. Microbiologist is involved in various research projects, respectively, within the competence of his work. Major responsibilities include conducting various experiments and research in the laboratories.
Education
Requires specialized secondary or higher specialized education.
Doctors of pharmacy and medicine
Scientists who have completed the teaching of Microbiology
Characteristics of staff
For a microbiologist requires accuracy, attention, patience and perseverance. All this is useful for his work in laboratories, research activities. Usually, microbiologists are considered as diligent and disciplined professionals, but if they are busy working in the field of soil microbiology or geology, then a specialist should be unpretentious, knowledgeable and possess managerial skills. This is important when participating in the possible long-term expeditions. The foundation provides a powerful analytical microbiology laboratory in which all major tests are carried out for cosmetics. On site Hygiene training to carry a high degree of improved industrial hygiene and safety of the products are carried out with the following activities:
Testing for microbial purity of;
Process water, raw materials and cosmetic products
Exclusion of pathogenic microorganisms
Testing for bacterial endotoxins
Identification of microorganisms and Check for adequate preservation
In preparation for topical application.
Repetitive stress tests
Microbiological efficacy of preservatives
In-use tests
Conclusion
The science of microbiology is a logical way of thinking independently and studying the microbiology of organisms which can be seen only through a microscope. This investigation includes bacteria and microscopic fungi, algae, and archaea, protista and viruses. Initially, the science of microbiology was developed with the first magnifying devices. Such appeared in the XV century thanks to the work of Galileo Galilee. Today, at the age of nanotechnology, there is a lot of different complexity allowing in making interesting study of microbiological processes.
Cosmetics can become contaminated with the resident micro-biota in the skin of the user. To avoid microbial contamination of cosmetics, the manufacturer must control every one of the possible pathways by microbiological analysis of raw materials, environment and equipment, while still an implementation plan for good manufacturing practices. However, even in these conditions ideal manufacturing and handling, the product obtained is not sterile, so there is always the possibility that an organism is incorporated into the product. When this occurs, microorganisms reproduce if conditions are right and cosmetics provide these ideal conditions of water content, oxygen and nutrients needed for proper development.
In order to ensure the quality and hygiene of the products, microbiology includes a general or specific quantitative evaluation on the basis of selected indicators. On the specific variety of pathogens are sought. The focus is on potentially pathogenic microorganisms on the skin, especially P. aeruginosa, S. aureus, coliforms and sulphite-reducing Clostridium. The importance of research of these organisms is their pathogenesis in skin and mucous membranes; coliforms or P. aeruginosa. In addition, they can indicate contamination of human origin.
Microbiology deals with production of goods and services with microbial cells. Therefore, Industrial Microbiology is a significant part of the cosmetic and skin care industry. In addition, once the product reaches the consumer, the microbiologist knows whether it will make a proper use of cosmetic or not if the container is left uncovered, adding water, poor hygiene use and under which certain conditions will be stored. For all these reasons, we can say with confidence that, under these conditions, cosmetic undergoes a close check up finding solutions that a cosmetic and skin care industry through which they may not compromise their quality and safety of using the product. Formulations that can withstand mo or are susceptible to microbial contamination must contain preservatives to retard microbial growth. The validity period - characterized as the period of life, during which the product maintains its original features - before becoming a legal requirement, is a technical requirement of quality as an unstable product from the standpoint of physical-chemical microbiological or toxicological, besides the loss of efficacy may also cause damage and compromise the reliability of consumer.
Cosmetics Directive includes the microbiological product safety. According to the specific products, requirements for microbiological purity and stability are sufficient so that it while the application is not for the user to a hazardous contamination of the product. In 7th Amendment of the Cosmetics Directive Regulation is an additional requirement includes Date-to-use consumer information of cosmetic products with a shelf life of more than 30 months have to be provided with a period of time (Todar, 42). From a microbiological point of view, this appears as not only required because of the Safety evaluation without setting a time limit - handled as before - no fundamental risk has revealed.
Works Cited
AM Kligman, “Regression method for assessing the efficacy of moisturizers”, Cosmet Toiletry, 2001, pp. 25-36.
Barnett, H.L. and Hunter, B.B. “Illustrated Genera of Imperfect fungi” Minneapolis: Burgess Publishing Company, 1972, pp. 62 - 63.
Faergemann, J. N. “Microbiological Testing During Clinical Trials,” Cosmetic and Drug Microbiology. New York, NY; Informa Healthcare, 2006, pp. 315-326.
Foster, E. M., et al., “Dairy Microbiology”, New York: Prentice-Hall, Inc., 1957, pp. 97.
Hafeez, Z. H., and Aly, R. “Microbiology of Skin,” Cosmetic and Drug Microbiology” New York, NY: Informa Healthcare, 2006, pp. 295-313.
Hollaender, A., “Radiation Biology”, Vol. II, , New York: McGraw-Hill Book Company, 1955, pp. 55.
Kabara, J.J. “Hurdle technology for cosmetic and drug preservation,” Cosmetic and Drug Microbiology, New York, NY: Informa Healthcare, 2006, pp. 163-183.
Kallings, L.O., Ernerfeldt, F., and Silverstolpe, L. “ Microbiological contamination of medical preparations. Report to the Royal Swedish Medical Board” Drug Cosmet Ind., 1975, pp. 40-41.
Koller, L. R., “Ultraviolet Radiation”, 2nd Edition, New York: John Wiley and Sons, Inc., 1965, pp. 236-256.
Luckiesh, M., “Germicidal, Erythemal and Infra-red Energy”, New York: D. Van Nostrand Co., 1946, pp. 23.
Orth, D.S. “Cosmetic products that prevent, correct or conceal conditions caused by microorganisms,” Handbook of Cosmetic Microbiology. New York, NY: Marcel Dekker Inc, 1993, pp. 221-323.
Orth, D.S. “Linear regression method for rapid determination of cosmetic preservative efficacy” J Soc Cosmet Chem, 1979, pp. 321-332.
Orth, D.S. “The probiotics nature of normal microflora” Cosmet Toiletry, 2008, pp. 44-46.
Pollack, M. “Pseudomonas aeruginosa: principles and practice of infectious diseases” Journal of Cosmetic formulation New York: Churchill Livingstone, 2006, pp. 2310-2327.
SCCS. “The SCCS's notes of guidance for the testing of cosmetic ingredients and their safety evaluation” European Commission, 2010, pp. 11.
Soni, M.G. "Safety assessment of esters of p-hydroxybenzoic acid (parabens)” Food and Chemical Toxicology, 2005, pp.5.
Todar, K. “Pathogenic clostridia: Ken Todar's microbial world” University of Wisconsin-Madison press, 2005, pp. 32-42.
United States Food and Drug Administration, “Bacteriological Analytical Manual Online: Staphylococcus aureus” FDA/Center for Food Safety and Applied Nutrition, 2001, pp. 52-69.
Wedderburn, D. L., “Hygiene in manufacturing plant and its effect on the preservation of emulsions” Cosmetic Chemists, 1965, pp. 395-403.
Wolven, A., and Levenstein, I. “Cosmetics—contaminated or not” TGA Scientific Conference: Washington, D.C., 1969, pp. 6-19.
Yablonski, J. I., and Mancuso, S. E. “Preservation of atypical skin care products and related cosmetic product systems” Cosmet Toiletry, 2003, pp. 31-40.
