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Explained: Sulfuric Acid Storage Requirements

Sulfuric acid is one of the most widely used chemicals in the United States. More sulfuric acid is produced every year than any other chemical. It has a multitude of industry-specific uses, such as the production of other chemicals, dyes and pigments, water treatment and fertilizers.


This heavy, corrosive chemical requires a specifically designed storage system. That’s why Poly Processing follows engineered guidelines that ensure safety and enhanced tank life.

In this article, we’ll look at why storing sulfuric acid is such an interesting challenge, and how we’ve adapted our tank system requirements to resolve these challenges. You’ll learn about our tank storage requirements for your own storage needs and get access to a downloadable guide for your reference.

sulfuric acid storage

Storage Challenges

Sulfuric acid presents a serious storage challenge because it’s a very heavy chemical, especially at high concentrations. At 93-98% concentration it is nearly twice the weight of water. It’s also an aggressive chemical that oxidizes plastic and corrodes metals.

When mixing or blending chemicals with sulfuric acid, an exothermic reaction may occur, and the heat of the chemical can cause damage if not properly addressed. All of these things should be taken into consideration when designing your sulfuric acid storage system.

For more information on sulfuric acid challenges, read our sulfuric acid storage guide.

Storage Guidelines & the 11/15 Rule

When storing sulfuric acid in a Poly Processing tank, just remember the 11/15 rule. You can use any tank less than 11,000 gallons and less than 15 feet tall. This includes the Vertical, IMFO®, Sloped IMFO®, and SAFE-Tank® Systems.

Other storage requirements for sulfuric acid vary, depending on the concentration of the chemical.

  • Concentrations of 93-98 percent: Because the weight is up to 16 pounds per gallon, 93-98% concentrated sulfuric acid must be stored in a tank that has a 2.2 specific gravity wall thickness. The OR-1000 System with PVC fittings, Viton Gaskets, and 316 Stainless Steel bolts are also required for this concentration.

  • Concentrations from 80 percent to less than 93 percent: Because this lower concentration of sulfuric acid can be corrosive to stainless steel, alloy C-276 bolts with Viton gaskets and PVC fittings are required along with a 2.2 specific gravity tank  and the industry-leading OR-1000 System.

  • Concentrations of less than 80 percent: a 1.9 SPG tank with the OR-1000 System can be used. Again the fittings required are PVC, with Viton gaskets and alloy C-276 bolts.

  • Tank recommendations for concentrations of 98 percent or less: Poly Processing's double-walled (SAFE-Tank) crosslinked polyethylene tank with the OR-1000 system is recommended. If containment is already provided, a full-drain IMFO or Sloped Bottom IMFO tank are excellent choices.

In all cases, the OR-1000® antioxidant system must be used. The OR-1000 system will provide enhanced tank service life by reducing oxidation (and storing in smaller quantities helps reduce overall risk).

For more information on our storage tank systems and options, get your copy of our Sulfuric Acid Position Statement.

Download Sulfuric Acid Position Statement

Topics: Chemicals