Sodium & Manganese Hypophosphite
Sodium and Manganese Hypophosphite are both hygroscopic and must be stored away from sources of moisture. Absorption of moisture will cause these products to clump, thus causing handling problems. In the case of Sodium Hy-pophosphite, OxyChem deliberately drives off some of the water of hydration from the monohydrate crystal (NaH2PO2 • H2O) in order to help combat this potential problem. In addition, these two products should not be stored near heat sources that could raise the product temperature near 100°C (212°F). These temperatures will cause the products to dehydrate, generating steam pressure.
Most customers use Sodium and Manganese Hypophosphite directly from the drum or bulk bag. However, if the customer wants to store these products in a bin or silo, we recommend that a dry nitrogen pad be used. It is also recommended that a vibrator(s) be installed on the discharge cone of the bin to assist in product flow.
Shelf Life
As with any product, the shelf life of the Hypo Products is partially dependent on how they are handled and stored. However, if sealed in their original containers and stored indoors in a cool, dry area, with minimal temperature fluctuations, separate from oxidizing agents (which are in-compatible) and away from direct heat and sun light, these products should be expected to have a shelf life of at least a year from the ship date.
Although the Hypo Products should be chemically stable for an indefinite time, it is generally recommended that all chemical storage adhere to a FIFO (First-In, First-Out) inventory practice to avoid long term storage. If moisture gets into the Sodium and Manganese Hypophosphite containers, these products tend to clump and may eventually create handling difficulties.
https://www.thevespiary.org/rhodium/Rhodium/pdf/hypophosphoric.pdf (https://www.thevespiary.org/rhodium/Rhodium/pdf/hypophosphoric.pdf)