text: Careful storage is needed when handling sodium hydroxide for use, especially bulk volumes. Following proper NaOH storage guidelines and maintaining worker/environment safety is always recommended given the chemical's burn hazard.
  Sodium hydroxide is often stored in bottles for small-scale laboratory use, within intermediate bulk containers (medium volume containers) for cargo handling and transport, or within large stationary storage tanks with volumes up to 100,000 gallons for manufacturing or waste water plants with extensive NaOH use. Common materials that are compatible with sodium hydroxide and often utilized for NaOH storage include: polyethylene (HDPE, usual, XLPE, less common), carbon steel, polyvinyl chloride (PVC), stainless steel, and fiberglass reinforced plastic (FRP, with a resistant liner).
  Sodium hydroxide must be stored in airtight containers to preserve its normality as it will absorb water from the atmosphere.