No, Yuka does not take into account the quantity of each ingredient for several reasons:
1) The quantity is almost never listed by manufacturers.
2) Some ingredients, especially those suspected of being endocrine disruptors, can cause problems even in very small quantities (i.e. there is no threshold effect).
3) Some ingredients, even when present in small quantities in any given product, are used in a wide range of products. Exposure to high quantities can therefore be quickly achieved.