An effective wood stain cannot actually be composed of food-grade raw materials, but there
are some potentially harmful chemicals to watch out for, including aromatic solvents, formaldehyde, phthalates and analine dyes. Some of these ingredients stay in the wood for a year or more after your initial application and continue emitting harmful chemicals into the air during that time. For a safer solution, look for low-odor wood stains to keep the air pure in your baby's nursery.
Water-based wood stains apply quickly, dry quickly, clean-up quickly, and produce significantly less odor than oil-based stains. For a higher degree of safety, look for a zero-VOC stain. Water-based stains tend to raise the grain of some types of wood. If that occurs on your project, lightly sand the affected area with an extra-fine grade of sandpaper or steel wool. Some woodworkers recommend using a wood conditioner before staining to prevent the grain raising effect.
Traditionally, oil-based stains have been the choice of professional woodworkers because oil permeates wood more effectively than water. Unfortunately, most popular brands of wood stain found in hardware stores and home centers rely on aromatic solvents to accelerate their drying times, and these are not good choices for an infant or toddler's room.
If you prefer oil-based stains, there are eco-friendly varieties formulated without aromatic solvents. Some have no solvents at all, but that means they may require three to five days to dry. Others accelerate drying times by using benign alternative solvents such as d-limeone, a citrus-based chemical that emits a mild aroma reminiscent of fresh orange peels.
After your stain has dried, you can apply a clear protective finish coat. There are several low-VOC and zero-VOC water-based varnishes that can safely be used with water-based stains. An oil/wax polish makes a safe but effective sealant over oil stains, and you can find solvent-free varieties at green building supply outlets.
Pioneer families used readily available materials for their wood stains and paint colors, and there's no reason modern families can't do the same. You have plenty of safe wood staining chemicals in your kitchen. Experiment with brewed coffee or tea, which can impart warm tones to lighter colored woods. Try food colorings to create a pickling stain effect. In either case, test the effect on scrap wood first. Rub your stain into the wood using an old, lint-free T-shirt. After the wood dries, seal the wood with a simple beeswax polish.