Tea-dyeing, maybe not

I've just read that tea-dye contains tannic acid (tannin) and will destroy fabric in 30 to 40 years. I had always *assumed* that tea-dye was harmless and had never thought it could be hurtful, especially since it's so quickly recommended by so many. Many times, I've tea-dyed lace for trim on newborn size pink bonnets and hoped that baby's mom would save the little bonnet for baby's own daughter. I haven't had any visions of making a quilt that Boston would build a museum for but I suppose the effect of tea-dye on a baby bonnet or quilt would be the same. Perhaps tea-dye isn't such a good idea. Polly