Cosmetics are rich in water and provide a suitable growth environment for microorganisms. These microorganisms can cause problems such as discoloration of the product surface, fluidity, pH value changes, performance, demulsification, odor, and even mildew on the surface. Controlling microbial growth is necessary from a product quality control and professional hygiene standpoint.
The microorganism is a general term for tiny and straightforward organisms with low-level structures. Microorganisms are ubiquitous and can multiply rapidly when the environment is right. They have the following characteristics:
① rapid reproduction. Bacteria can reproduce one generation in tens of minutes under laboratory conditions. For example, Escherichia coli 20min can reproduce in one generation
② is widely distributed. Where there are higher organisms, there are microorganisms living and also microorganisms in extreme environments where animals and plants cannot live
③ significant number. There are many microorganisms in the local environment, such as tens of millions to hundreds of millions of microorganisms per gram of soil;
④ prone to mutation. After treatment with physical and chemical factors, microorganisms are prone to mutation.
There are many mutagenic factors, so new microorganisms are constantly produced to adapt to the new environment. For example, resistant Staphylococcus aureus has been found in cosmetics.
1.The characteristics of microorganisms
The growth of microorganisms depends on temperature, pH, moisture, and nutrients. Cosmetics have abundant moisture and nutrients, which can encourage the growth of microorganisms. There are roughly two types of microorganisms common in cosmetics that cause harm: bacteria and fungi. Most bacterial contamination is caused by gram-positive bacteria such as Staphylococcus aureus, streptococcus, spores, and clostridium. Gram-negative bacteria such as Pseudomonas, Salmonella, and Vibrio are also common contaminants. Cosmetics are also often contaminated by pathogenic fungi such as Penicillium, Aspergillus, Rhizopus, and Mucor.
2. Microbial contamination control in cosmetic factories
There are two primary sources of microbial contamination in cosmetics:
① Microbial contamination in the cosmetic production line, including air, production water, other raw materials, production equipment, and packaging materials
② Secondary pollution during use, such as end consumers. The methods of controlling microbial contamination in factories mainly include strict production management, such as using raw materials with qualified microbial indicators, keeping the environment clean, cleaning factories, and taking disinfection measures. Microorganisms can spread in the production workshop through many channels, such as dirty water, waste, air, workpieces, operators, and production processes. Microorganisms can cause many hazards to products if not controlled.
3-1. Quality control of raw materials
The essential raw material requirement is a low bacterial content. For liquid raw materials (such as water, emulsion, defoamer, etc.), it is necessary to control the number of microorganisms <1,000/mL. Because the microbes are so tiny, they are invisible to the naked eye. Therefore, it can use the method of measuring bacteria or ATP on-site to detect the contamination of microorganisms.
The microbial risk classification of raw materials is carried out according to the susceptibility to microbial contamination. Category 1, low microbial risk: preservatives, colors/flavors, surfactants with pH < 3.5 or pH > 10, high concentrations of surfactants (>70%); Category 2, medium microbial risk: synthetic raw materials; Category 3, high microbial risk: production water, surfactants (<30%), natural extracts or hydrolyzed proteins, colorants, natural polymers such as starch, thickeners or emulsions, etc. The storage of raw materials faces various risks of contamination. To ensure their quality remains stable, “first in, first out” is a principle that should be followed. Preservatives are generally sensitive to high temperatures, so liquid additives should be stored in a cool place and the product tested for microbial contamination before use. Standard process water disinfection methods include physical and chemical disinfection, such as chlorine dioxide, sodium hypochlorite, ozone, ultraviolet rays, and membrane disinfection. Among them, the chlorine dioxide and sodium hypochlorite methods should pay attention to the problem of equipment corrosion caused by long-term use while monitoring the ozone content of process water in real time due to its instability.
3-2. Cleaning and disinfection of equipment and pipes
Cosmetics production equipment includes emulsification tanks, storage tanks, pipes, valves, joints, flow meters, filters, pumps, and filling machines. Incomplete cleaning and disinfection will breed microorganisms in the equipment and pipelines. It must be cleaned first to kill the microorganisms in the production equipment and pipelines. To prevent the dirt from becoming a protective umbrella for microorganisms must remove the adhered dirt in the equipment and pipelines. Pay special attention to dead corners that quickly accumulate residues and must be disassembled before they can be cleaned up. Residues are an essential source of microorganisms. Where they quickly accumulate include valves, outlets, inlets, and filters. After cleaning, equipment and pipelines must be sterilized. Commonly used sterilization methods include steam, hot water, and chemical sterilization. When using steam sterilization, the equipment to be sterilized must be heat-resistant, and the effect of sterilization is related to the contact time. It generally takes 30 minutes to sterilize open containers. Hot water disinfection generally uses 90 ℃ hot water for circulation, which is more suitable for pipeline disinfection. Chemical disinfection uses various chemical disinfectants, which is cold disinfection without heating. When conducting chemical disinfection, it’s essential to understand the material and disinfectant’s performance and ensure the disinfectant’s appropriate concentration and action time. It should be noted that some chemicals, such as sodium hypochlorite, have solid oxidizing properties, and long-term use will cause corrosion to equipment and pipes.
3-3. Disinfection of production environment
Unclean air contains a variety of microorganisms that can contaminate products in the manufacturing, sanding, filling, and packaging of cosmetics. The “Hygienic Specifications for Cosmetics Manufacturing Enterprises” has precise requirements for the total number of air bacteria in the cosmetics production environment: the total number of bacterial colonies in the air during the production process should be ≤1 000 CFU ／m3; the total number of bacterial colonies on the workbench in the filling room should be ≤20 CFU/cm2, and the total bacterial colonies on the surface of workers’ hands should be ≤300 CFU/hand and should detect no pathogenic bacteria. The sampling and inspection methods refer to GB/T 5979-2002 ”Hygienic Standard for Disposable Sanitary Products”. To better control the air index of the production workshop, it is recommended to install an air filtration system with high, medium, and low-efficiency filters so that the air entering the workshop can meet the cleanliness requirements.
Microbial control of cosmetics is a comprehensive concept that requires professional factory hygiene supervision and suitable preservative selection and use. The hygiene supervision of the factory is detailed work. Only by strictly controlling all aspects such as raw materials, environment, equipment, and packaging, can the microbial safety of cosmetics be fully guaranteed.
Being a leading skin care & hair care cosmetic manufacturer, Ausmetics is committed to providing high-quality products with efficient service. The company has a set of professional R&D team, with strong capabilities in innovation and technology development. Ausmetics cosmetics production is produced with high-quality raw materials and packaging materials. Our cosmetics manufacturing process also involves incoming inspection of raw materials/packaging materials, semi-finished product inspection, microbiological inspection of finished products and final inspection of finished products to ensure that only high-quality cosmetics products are released for sale.
Jack Li
Product Manager
