For the production of organic and organic-mineral fertilisers, various types of plant and animal waste substances are used, as well as sewage sludge, which, despite the composting process, may often not be completely safe for humans.
Organic fertilisers are chemically and biologically contaminated and contain a huge load of bacteria, viruses, fungi, eggs of intestinal parasites of humans and animals. These organisms introduced with fertilisers into the soil in an uncontrolled manner, not in accordance with the rules in force, will contaminate the soil translating into crop contamination. Microorganisms and other pathogenic organisms have a long survival rate. The most common diseases as a result of soil biological contamination are salmonellosis, tapeworms and worms of the digestive tract. Eggs of human roundworms survive for about six years, eggs of parasites of carnivorous animals for up to 10 years. The Act on Fertilisers and Fertilisation and a number of ordinances of the Minister of Agriculture and Rural Development specify exactly what tests need to be carried out for a fertiliser to be authorised.
The use of mineral fertilisers entails hazards of chemical burns to the skin and respiratory system of the operator, eye damage in the event of splashes or splashes of liquid or dissolved fertilisers, especially those that heat the solution strongly (exothermic). Hazards may also arise from gases or vapours from stored or applied fertilisers.
Improper use of mineral and organic fertilisers entails serious risks for the environment, especially for surface and groundwater in the event of over-fertilisation, errors in application technique or extreme weather events.