Fact sheet on molds

General information
Moulds are a heterogeneous group of filamentous fungi. Most moulds belong to the taxonomic groups of sac fungi (Ascomycota) and zygote fungi (Zygomycota).

Moulds are widespread in our environment and can therefore also occur in cosmetic products. In cosmetics they are considered typical spoilage organisms that can pose a hygienic or toxicological risk. ISO 17516 also sets limits for the total number of aerobic microorganisms. This is the sum of the numbers of bacteria, yeasts and moulds. For cosmetics in general these limits are 1000 CFU. For cosmetics for children under 3 years as well as for applications in sensitive areas such as the eyes, mouth or intimate areas the limit is 100 CFU/g

Characteristics

• Spore-forming
• Form visible mycelium
• Toxin producers (mycotoxins)

Origin / occurrence

• Moulds are widespread in our environment (e.g. soil, plants, air, water, humans, …).
• Common contamination sources in cosmetics are plant-based raw materials, contaminated air, dust ingress, inadequate hygiene during manufacture or packaging, moisture ingress such as condensate in closed drums.

Significance

• Moulds can lead to microbial spoilage of cosmetic products and thus impair product safety, stability and consumer acceptance.
• Depending on the composition of the cosmetic product (e.g. high water content, plant ingredients) there is an increased risk of mould infestation. Visible mycelium formation is always an indication of mould growth and microbial spoilage.
• Some mould species can also grow at low water contents and/or low pH values.
• Health risks mainly arise from contaminated products intended for oral use (foods).
• As some moulds can produce toxic mycotoxins, their ingestion can lead to gastrointestinal complaints but also to poisoning, liver damage, allergies and respiratory diseases.

Growth conditions

• Temperature:
  
  • Optimum: +25 °C to +35 °C
  • Minimum: 0 °C
  • Generally no growth above +50 °C
• pH: Growth at pH 2.0 to 9.0 (most species grow optimally between 3.5 and 7.0).
• a_w value: According to ISO 29621 cosmetics with an aw value of less than 0.75 are considered low-risk, as microorganisms generally cannot reproduce at this water activity.
• Some moulds are osmophilic/osmotolerant or acid-tolerant. This means they can still grow at low water activity or low pH values.
• Oxygen requirement: aerobic (growth only in the presence of oxygen).

Inactivation by heating

• At +72 °C with a minimum exposure time of 2 minutes most moulds are killed (Note: monitor core temperature) → Note: there are also heat-resistant mould species (e.g. Neosartorya fischeri, Byssochlamys nivea, Talaromyces flavus, and Eupenicillium spp).
• Mould spores are inactivated at a core temperature of +80 °C.

Errors in cleaning and disinfection as well as inadequate ventilation hygiene:
The result is contamination of cosmetics by e.g. microbially contaminated work equipment, utensils, surfaces, machines or poor production hygiene

Note on air hygiene:

Insufficient ventilation, unhygienic ventilation systems, high relative humidity and high moisture on ceilings, walls and windows can lead to elevated airborne mould counts

1. Check cleaning and disinfection procedures:
   1. Hygiene plan specifying how cleaning and disinfection are to be carried out, e.g. dosing, contact time, use of suitable and clean materials and cleaning cloths
2. Train staff on potential errors and corrective measures
3. Repeat cleaning and disinfection
4. Verify effectiveness by on-site inspections and follow-up tests (e.g. contact plate and swab tests)

1. Check incoming goods for e.g. shelf life, packaging, deviations or microbiological abnormalities
2. The same applies to goods before use in production. Do not use raw materials if contamination is suspected
3. Review microbiological specifications. If necessary, arrange laboratory testing of suspicious products or request results from the supplier
4. Verify effectiveness by follow-up testing

1. Check and document production processes
2. Train personnel
3. Verify effectiveness by regular microbiological product testing

1. Check and document production processes
2. Train personnel
3. Verify effectiveness by regular microbiological product testing

1. Check airborne microbial counts and ventilation systems by technical inspection and environmental testing
2. Avoid high humidity and condensate formation
3. Appropriate cleaning and disinfection (see section “Cleaning and Disinfection”)
4. Train staff on potential errors and corrective measures
5. Verify effectiveness by on-site inspections and follow-up tests