The modern cleaner was invented by housewives Elizabeth "Bet" MacDonald and Naomi Stenglein in Saginaw, Michigan in 1933.[citation needed] Their formula included equal parts of ground-up glue, sodium carbonate, and trisodium phosphate; though trisodium phosphate is no longer part of the modern formula out of a concern for environmental damage from phosphates making their way into waterways.[citation needed] Stenglein observed that testing in her house made it spotless, or "spick and span". They took the k off Spick and started selling the product in brown envelopes to local markets.