Caustic soda is classified as a dangerous good for transport. Whether it moves by road, sea or air, the packaging, labels and documents have to be right. This guide covers the basics for solid caustic soda flakes and pearls.

The key identifiers

Item	Solid caustic soda
Proper shipping name	Sodium hydroxide, solid
UN number	UN 1823
Hazard class	Class 8, corrosive
Packing group	II
CAS number	1310-73-2
HS code (solid)	2815.11

Liquid caustic soda (lye) travels under a different UN number, UN 1824, so check which product you are shipping.

Packaging

• Flakes are normally packed in 25 kg woven polypropylene bags with a polyethylene liner, or in larger bulk bags.
• Packaging must be approved for Packing Group II and kept intact; caustic absorbs moisture through damaged bags.
• Bags are usually palletised, often 40 bags (one tonne) per pallet, and stretch-wrapped.

Labels and marks

• The Class 8 corrosive hazard label on each package.
• The UN number and proper shipping name.
• Product name, net weight, batch number and supplier details.

Documents

• A dangerous goods declaration for sea or air shipments.
• The safety data sheet (SDS) with all 16 sections.
• A certificate of analysis for the batch.
• Commercial invoice and packing list with the correct HS code.

Stowage and segregation

Keep caustic soda away from acids, from foodstuffs, and from metals it attacks such as aluminium and zinc. In containers, use dry, clean units and secure the load so bags cannot tear.

Buying locally instead of shipping

Moving dangerous goods across borders adds cost and paperwork. For sites in Oman, buying from local ready stock is usually simpler. MBBT keeps caustic soda flakes 99% in Barka, with the SDS and a sample COA online, at muscatchemical.com/caustic-soda, and delivers within Oman.