Caustic Soda (80%) is very concentrated sodium hydroxide (NaOH, CAS 1310-73-2). At this strength caustic is solid at room temperature, so it is handled hot or molten, or as flake and bead caustic that is dissolved on site. It is used where water must be kept to a minimum, such as in specialty chemical synthesis and in making high-strength cleaners. Because it is stored at elevated temperatures, check each tank resin's temperature limit. Use the compatibility ratings to choose the right tank resin, fittings and gaskets.
Safety data: Caustic Soda Solution Safety Data Sheet (SDS) – Formosa Plastics USA
Polypropylene is the recommended tank material for Caustic Soda (80%), rated Excellent. Avoid PVDF (Kynar®) tanks; PVDF fittings; Buna-N and Viton® gaskets; titanium hardware. Rated Fair (contact us before use): HDPE and nylon tanks; HDPE fittings.
How Caustic Soda (80%) works with the plastics used to make our storage tanks.
| Material | Relative cost | Rating |
|---|---|---|
| HDPE $ | $$$$ | C Fair |
| Polypropylene $$ | $$$$ | A Excellent |
| Nylon $$$ | $$$$ | C Fair |
| PVDF (Kynar®) $$$$ | $$$$ | D Not Recommended |
How Caustic Soda (80%) works with the plastics used for tank fittings.
| Material | Rating |
|---|---|
| HDPE | C Fair |
| PVC | A Excellent |
| CPVC | A Excellent |
| Polypropylene | A Excellent |
| PVDF | D Not Recommended |
How Caustic Soda (80%) works with gasket and O-ring materials.
| Material | Rating |
|---|---|
| Buna-N | D Not Recommended |
| EPDM | B Good |
| Viton® | D Not Recommended |
How Caustic Soda (80%) works with the metals used for fittings and bolts.
| Material | Rating |
|---|---|
| 316 Stainless Steel | B Good |
| Hastelloy | A Excellent |
| Titanium | D Not Recommended |
| Aluminum | — No Data |
Storing this chemical in polypropylene?
Polypropylene tanks from 25 to 6,000 gallons with polypropylene fittings installed. Confirm concentration and temperature with us before you order.
Send the chemical, concentration, temperature and size. We’ll match the tank and fittings and send a quote.