enfamil powder with black particles

We've been feeding our two months old baby with enfamil w/iron powder. Recently we noticed balck and brown particles, like peppers, coming down to the bottom after adding warm water. :o We don't want to change the brand right now and want to keep using powder because of the price and convinience, so always decant to get rid of the particles.
According to the customer service of Enfamil, those are formed during the process of making powder, appearance depends on the batch and ARE SAFE! I was personally very disappointed that the company knows the problem and is not getting rid of those particles (or it's not a problem?). How can they assure that these by-products are safe? Am I too sensitive? Are you comfortable feeding your baby with those? How are other brand powders?

We use powdered Similac with Iron, and I've never noticed any black particles in it. That sounds pretty gross! Have you thought about switching to Similac instead??

Try this. Use a magnet to collect the particles. If they stick, that is the iron particles. You can do this with any iron enriched food, including Total cereal. But I'd still call the manufacturer just to make sure.