Microbiology laboratory 5 Algicidal product testing

How do we test the conformity of an algicidal product?

The algicidal capacity of a biocide product is evaluated with regards to its guaranteed efficacy with minimum risk to the environment and human health.

What are microalgae?

Microalgae are microscopic unicellular or multicellular organisms generally found in water and which can perform photosynthesis. They belong to a diverse taxonomic groups but the largest families of microalgae comprise :

  • Green algae (Chlorophyta): These microalgae are often present in ponds, lakes, rivers and other aquatic environments. They are green due to their pigmentation.
  • Blue-green algae (Cyanobacteria): These are microorganisms able to perform photosynthesis and which usually are found in water. They are often called blue-green algae.
  • Diatoms: These are unicellular microalgae with an external skeleton made of silica. They are mainly found in sea and fresh water.
  • Red algae (Rhodophyta) : These microalgae are frequently multicellular and are found in sea water. They are red due to their pigmentation.

Microalgae are capable of colonizing numerous types of environment. Their excessive proliferation can cause environmental and health issues. Algae develop for example in swimming pools or on the facade of houses due to the presence of nutriments, sunlight and favorable temperatures.

In order to control these proliferations, algicides are often used. However, their use is strictly regulated to minimize their negative impact on the environment. Regulations concerning the use of algicides (chemical or natural products aimed at destroying algae) vary from one country to another but are generally controlled by government bodies charged with the protection of public health and the environment.  Regulatory authorities establish norms for the safety and efficacy of algicides. Manufacturers must perform tests and studies on their products in order to show that they conform with these norms.

Why and how to test the efficacy of an algicidal product?

The laboratory evaluation of the algicidal efficacy of a chemical or natural product provides a better understanding of their mechanism of action which in turn helps justify their correct usage.

In our laboratory, we have developed protocols allowing us to artificially recreate natural environmental conditions in order to evaluate the algicidal efficacy of a test product.

These protocols were conceived with particular attention to detail to faithfully reproduce specific environmental conditions within which microalgae proliferate well. By controlling factors such as temperature, pH or hydraulics , we can perform precise and reproducible measurements which simulate real-life situations to which algicides could be confronted.

Methods used to evaluate the efficacy of an algicidal product

Our laboratory has developed innovative methods to evaluate the efficacy of algicidal products on surfaces or in water, providing you with precise scientific data.

icone Aquarium

Testing efficacy in liquid medium

  • Evaluation of the preventative or curative action in swimming pool- or spa -type environments
  • Tests according to OECD 201 guidelines
  • Tests according to OECD 170 guidelines
matériau à tester

Testing efficacy on surfaces

  • NF-EN 15458 (2022) Paints and varnishes — Laboratory assessment method to determine the efficacy of preservatives, present in a film covering, against algae.
  • Evaluation of the preventative or curative action on surfaces such as facade coatings, concrete slabs, pavings etc.. 

Our solutions associated with algicidal product testing

Microbiological analysis of air

Analysis of contaminated material

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