EN 13623: 2021 and BPR: 2023.  Quantitative suspension test for the evaluation of bactericidal activity against Legionella of chemical disinfectants for aqueous systems - Test method and requirements (phase 2, step 1). 

Test accredited by ENAC (Spanish National Accreditation Entity).

This test is performed according to EN 13623 Standard adapted according to the specific conditions of the BPR Guidance. This test uses Legionella pneumophila serogroup 1 as a mandatory organism. The maximum concentration of the product in the test is 10%, if used pure, or the concentration chosen by the client lower than 10%. The test dilutions are made in hard water. According to the BPR Guidance, the test must be performed at a mandatory temperature of 15ºC. Furthermore, this Guidance state that for EN 13623 test, the standard soiling of the test can be used, or the test can be adapted with the soiling stated by the BPR (Clean: 2mg/L DOC, Dirty: 15mg/L DOC).

The analysis of the bactericidal activity against Legionella is only mandatory for collective drinking water systems. This analysis should be performed with a contact time of 25 minutes and clean conditions. For other intended uses, see the table below. For this reason, these characteristics of the product must be indicated.


Intended use of the product to evaluate

Contact time

Soiling conditions

PT5 Drinking water suppliers and their water distribution systems

Max 30 min

Clean (2 mg DOC/L) for secondary disinfection /dirty (15 mg DOC/L) for primary disinfection.

PT5 Raw water for individuals supply (1-2 premises)

Max 30 min

Dirty (15 mg DOC/L)

PT5 collective drinking water systems

25 min

Clean (2 mg DOC/L)

PT5 water in reservoirs

As claimed

Clean (2 mg DOC/L) for origin from drinking water supplier only/ dirty (15 mg DOC/L) for origin raw water.

PT5 Water of undefined quality for small scale use (up to 5L/ person/day).

Max 30 min

Dirty (15 mg DOC/L)

PT5 Water for animals

Max 30 min (for continuous use the contact time is max 30 minutes. For reservoir water for animals the contact time should be as claimed).

Clean (2 mg DOC/L) for origin from drinking water supplier only/ dirty (15 mg DOC/L) for origin raw water.

The product must be tested for at least three concentrations including one in the non-active range and one in the active range (these two concentrations are chosen by the laboratory that performs the test because they correspond to the positive control and the negative control, respectively). The dilution-neutralization or filtration method can be used. To consider the product as bactericidal for Legionella, a log reduction of 4 or more in the number of viable cells must be obtained.