This International Standard describes artificial weathering tests intended to evaluate plastics for use in heavily polluted outdoor environments. Results from this International Standard cannot be used to predict the service life of these plastics. This International Standard describes two different exposure methods. Use of the methods depends on the form of the plastic product being evaluated. Method A is intended for products where surface degradation is very important and uses a strong acid spray (pH 1,5) that is applied for a short time. Method B uses a weaker acid spray (pH 3,5) that is applied over a long period of time so that it can penétrate deeply into the product and is intended for products such as geotextiles and related products. This International Standard does not cover the influence of special chemicals like agrochemicals.