Determine Resistance of Paints & Coatings to Fungal Defacement
ASTM D5590 : 2021 – Fungal Defacement Test
ASTM D5590 is used to determine the resistance of paint films and related coatings to fungal defacement by accelerated four week agar plate assay.
Fungal growth (mold and mildew) is a common cause of deterioration of paints and coating films. The major factors that support and encourage fungal growth include temperature, substrate pH, humidity and including composition of paints/coating materials. Due to this aesthetic damage becomes noticeable in the form of discolorations/stains and rough or powdery surfaces.
ASTM D5590 is similar to ASTM G21, however there is an exception of nutrient growth media used for both tests. ASTM G21 utilizes nutrient-limited media (carbon free) that might affect growth of fungi. On the other hand, ASTM D5590 uses nutrient-rich medium (Malt Agar) on which fungi can grow with relative ease unless antimicrobial agents hinder the growth.
ASTM D5590 standard is designed to determine the relative performance of different coating formulations under a set of conditions that can trigger fungal growth.
ASTM D5590 Test Preparations
Test microorganisms – This antifungal activity test uses Aspergillus niger, Penicillium funiculosum, and Aureobasidium pullulans. Aspergillus niger and Penicillium funiculosum can be tested together on the same plates while Aureobasidium pullulans (mildew organism) is tested separately.
Sample preparations – Paints/coating samples to be tested can be applied on glass fiber filter paper disks (of size 4.2-cm) or to drawdown strips of size 28 by 216-mm. These test specimens are placed in the center of agar media.
ASTM D5590 Test Method
- A thin, even coating of fungal suspension is spread over test specimens which are pre- placed in agar media.
- Plates are incubated at 28°C under relative humidity conditions (85 to 90%) for 4 weeks.
- Results are evaluated on the basis of following values –
|Observed Growth on Specimens||Ratings|
|Traces of growth (<10 %)||1|
|Light growth (10–30 %)||2|
|Moderate growth (30–60 %)||3|
|Heavy growth (60 % to complete coverage)||4|
Are you looking for ASTM D5590 testing for your product samples! Experts at MIS would be happy to assist you.
Our antifungal testing services are perfectly curated to help our clients to ensure the quality of and functionally of their products.
To find more information about ASTM D5590 or other paints & coatings testing, contact our experts now.
ASTM D5590 is an antifungal testing method which is used to determine the resistance of paints/coating materials to fungal defacement under optimal lab conditions.
Paint films and coating materials are tested using ASTM D5590 standard.
ASTM D5590 test takes 4- 5 weeks to complete.
At Microbe Investigations, we test for ASTM D5590 using the following microbial strains: Aspergillus niger (ATCC-16888). Additional strains can be added on customer’s request.