2. 6. 4. Ban of biocide use in facade plasters and paints

Algal growth on building facades has recently turned out to be a specific issue. Algal growth is stimulated mainly on facades that have been moist over longer periods. While algae do not destroy the facade, they are an aesthetical problem, and as mould also tends to develop under such conditions, this may lead to structural damage, which can be prevented by regular maintenance.

The conventional algal control measures are questionable from an ecological point of view: applying biocide coatings or adding biocides to the finishing mortar. Even though these measures do have preventive and delaying effects, they cannot ensure the absence of algae in the long run either. The biocidal agents are only effective if they are soluble in water. As a consequence, they degrade when exposed to rain and the UV radiation of sunlight.

 

The Act on Biocidal Products is aimed at reducing the use of biocides to a sensible, necessary minimum, also by a combination of physical, biological, chemical and other relevant measures. Construction measures such as eaves, sheeting, splash protection etc. continue to be the best, and most environmentally friendly, protection against algal growth on facades.

 

Facing plaster and paints must not contain biocides, with the only exception of the following biocides as alternatives to in-can preservation:

• ≤ 100 ppm silver chloride (deposited on titanium dioxide)
• ≤ 200 ppm MIT/BIT in a ratio of 1:1
• ≤ 15 ppm CIT/MIT in a ratio of 3:1
• ≤ 80 ppm IPBC
• ≤ 200 ppm BIT
• ≤ 200 ppm BNPD
• ≤ 130 ppm BNPD + ≤ 15 ppm CIT/MIT (3:1)
• ≤ 150 ppm BNPD + ≤ 10 ppm CIT/MIT (3:1)
• ≤ 170 ppm BNPD + ≤ 5 ppm CIT/MIT (3:1)
• ≤ 150 ppm MIT/BIT (1:1) + ≤ 12.5 ppm CIT/MIT (3:1)
• ≤ 125 ppm MIT/BIT (1:1) + ≤ 15 ppm CIT/MIT (3:1)
• ≤ 500 ppm (0.05 % m/m) 1,2-dibromo-2,4-dicyanobutane (DBDCB)
• ≤ 150 ppm BIT + ≤ 12.5 ppm CIT/MIT (3:1)
• ≤ 120 ppm BNPD +≤ 75 ppm MIT/BIT (1:1)
• ≤ 100 ppm ZnP + ≤ 100 ppm BIT
• ≤ 50 ppm ZnP + ≤ 150 ppm MIT/BIT2) (1:2 to 1:1)
• ≤ 100 ppm BNPD + ≤ 100 ppm BIT2)
• ≤ 50 ppm NaP + ≤ 150 ppm BIT

BIT = 1,2-benzisothiazol-3(2H)-one
CIT = 5-chloro-2-methyl-4-isothiazolin-3-one
MIT = 2-methyl-4-isothiazolin-3-one
IPBC = 3-iodine-2-propynyl-butylcarbamate
BNPD = 2-bromo-2-nitropropane-1,3-diol

ZnP = zinc pyrithione

NaP = sodium pyrithione

Supporting documents:
Safety data sheet in accordance with Regulation (EC) No 1907/2006 as amended by Regulation (EU) No 453/2010, or manufacturer's confirmation.

 

All products bearing one of the following organic labels meet these criteria:

• natureplus quality label.

Alternatively, the corresponding baubook declaration may serve as evidence (www.baubook.info/oea)

Since May 1, 2020, products containing 2-methyl-4-isothiazolin-3-one (CAS 2682-20-4), abbreviated MIT, from a concentration of 15 ppm, have been classified with hazard warning H317 (May cause allergic skin reaction). The sensitizing effect of chloromethylisothiazolinone (CIT) has also been well known for a long time.
The "ÖkoBauKriterien" (eco building criterion) "2.6.1 Limits for biocides" and "2. 6. 4. Ban of biocide use in facade plasters and paints" has been adapted to this situation and the use of CIT, MIT and CIT / MIT (3: 1) has been limited to 15 ppm.
The sum of the allowed preservatives was increased to 400 ppm. To simplify the criterion and also to resolve existing contradictions, the limitation to individual combinations of active ingredients has also been removed from the criterion.
Additional Information here

 

Criteria change valid from: 1.7.2021