All Plan Toys are made with clean, natural rubberwood from rubber trees which no longer produce latex. To keep the rubberwood pure, no fertilizer is added to the soil for 3 years before the trees are cut. To strengthen the wood, Plan uses a special chemical-free kiln drying process. Plan Toys are also all assembled using non-formaldehyde E-Zero glue. They also use only safe, non-toxic, water-based dyes on all of their toys.