Recently, industrial and food manufacturers are facing increasing instances of microbiological infections and mould infection problems for their products and factories. Specifically, TÜV Rheinland Vietnam Laboratory received no requests for mould infection tests in 2014 and only receive 5 requests in 2015. In 2016, we receive up to 20 enquires which had led to 2 comprehensive facility inspections in 2016. In 2017 Q1, there have been at least 5 factories which underwent comprehensive production inspections to identify causes and remedial measures for mould infections in their products. Clearly, mould infection problems have become so serious that manufacturers should pay more attention in order to improve their product quality to meet higher consumer demands.
Various mould types are useful for human beings as they can:
- Synthesize antibiotics (penicillin, griseofulvin), organic acids (oxalic acid, citric acid, gluconic acid), vitamins (B group, riboflavin), hormones (gibberellin, auxin, cytokinin), some enzymes and other active elements used in food, medical and pharmaceutical industries.
- Dissolving organic matters to enrich the soil.
Some types of moulds are very useful in production and living activities, naming edible mushrooms, pharmaceutical moulds (Lingzhi mushroom, Penicillium notatum for penicillin synthesis, Penicillium griseofulvum for griseofulvin synthesis, Aspergillus niger for synthesis of citric acid and gluconic acid, and Gibberellafujikuroi for synthesis of gibberellin hormone). Besides, some types of Phycomycetina and Deuteromycetina can be used as natural enemies of harmful insects because they can parasitize those insects. Moreover, some plant-symbiotic fungi, e.g. Mycorrhizae, which help plant roots absorb hardly soluble inorganic fertilizers more easily, can be used for growing demand of plants.
Deleterious effects of moulds
Moulds can have direct adverse impacts on human life, decay and degrade foods and foodstuffs prior to and even after crops, processing and preservation processes. Moulds also damage supplies, clothes, footwear and cause various diseases in human beings, animals and plants.
For instance: Species of Rhizopus, Mucor and Candida cause diseases in human beings, Microsporum in dogs, Aspergillus fumigatus in birds; Saprolegnia and Achlya parasitize on fishes, Phytophthora, Fusarium and Cercospora on plants. On the other hand, Aspergilus flavus and Aspergillus fumigatus on cereals may produce aflatoxin, a dangerous toxin.
As contaminants to human body, infectious moulds attack respiratory tract, irritate skin, nasal mucosa, bronchi and cause snuffles, coughing, sneezing and infection of immune system. Also, aflatoxin contamination may lead to the development of cancers.
Mould infection sources
Most mould can grow in temperatures of 2-5 oC at the lowest, 22-27 oC at the optimal and 35-40oC at the highest. In particular, a few species may survive at more extreme temperature, e.g. 0 oC or 60 oC. So moulds grow well in humid and unventilated environment and multiply easily in an unhygienic environment. Remarkably, mould spores can scatter everywhere through the air.
In factories, exposures to high levels of mould infections are common at raw material stores, finished product warehouses, areas surrounding air conditioners and evaporators, etc.
Mould preventive measures in factories
Factories nowadays are using air conditioners, ventilation systems in combination with facility sanitation as mould preventive measures. However, inadequate frequency, lack of proper cares and control in application of such measures may result in undesirable effectiveness.
To prevent the development of moulds and eliminate mould infection sources in production environment and products, it is advised to apply such optimal measures as follows:
- Cleaning the air;
- Finding out wet/dank areas and applying proper treatments such as sealing leakages along water supply and drainage systems to keep the environment clean and dry;
- Applying regular sanitation measures; installing proper ventilation system and avoiding unnecessary moisture;
- Applying mechanical sanitation measures in combination with specialized surface antiseptics and disinfectants;
- Making sanitation instruction plans with adequate application frequencies in accordance with specific production conditions;
- Equipping proper labour protective means;
- Applying strict rules for personal hygiene;
- Keeping equipment, devices, tools and wrappings at clean, dry and airy places to avoid cross-contamination;
- Isolating sources of infection (wastes, infected products and tools, foods etc) from production areas.