Cellulose acetate-based plastics have shown signs of chemical degradation resulting in a release of acetic acid. The application of zeolite 4A in storage containers as a desiccant and as an acid absorbent to slow down this so-called vinegar syndrome has been suggested by some researchers. This study focuses on the possible effectiveness of zeolite 4A as an acid absorbent. The absorption behaviour of zeolite towards vapours of acetic acid and water in various ratios was measured experimentally. It was found that the combined absorption of water and acetic acid resulted in a reduced effectiveness of zeolite as an acid absorbent. For water-permeable storage boxes significant reductions of acidity levels within cellulose acetate-based material are to be expected only when large amounts of zeolite 4A are added. -- SCMRE