Insider Highlight: NSF Certification for Flexible Storage Tank Textiles

International StandardsMay 21, 2018
nsf certification

Share this Post


Flexible storage tanks are lightweight, foldable bladders used to store liquids. Often, the liquids being stored are drinking water or foods such as oils, wine, or milk. When used in these applications in the United States and Canada, tanks and their components must meet and be certified under a recognized safety standard such as the NSF/ANSI 61 standard (NSF 61). Certification ensures that these products do not leach harmful contaminants into the food or water.

NSF 61

NSF 61 was developed by the National Sanitation Foundation (NSF), a global independent public health and environmental organization, and the American National Standards Institute (ANSI), which oversees the development of manufacturing and procedures standards in the US and Canada. NSF 61 certification ensures regulatory compliance in 48 U.S. states and 11 Canadian provinces, and it often meets/fulfills the testing requirements for many other countries as well. Annual testing of both the products and the manufacturing facility is required to maintain certification. Products that meet this standard usually bear a label indicating compliance.

In the case of flexible tanks, the tank fabric is classified as a “Protective (barrier) Material” and the contact coating is classified as a “Liner.” Barrier materials and liners are rated according to:

  • Water surface to volume: a calculated ratio that results in a Water Contact Size Restriction limit, and
  • End-use water temperature or Water Contact Temperature

All Erez coated fabrics intended for flexible tank use are rated CLD 23 (cold water), meaning they are “intended to apply to product applications where the product is used for continuous exposure to ambient water temperatures.” (1) Erez tank fabrics have contact-size restrictions ranging from 50 – 20,000 gallons.

Erez Fabric Coatings

Erez flexible-tank coated fabrics with NSF 61 certification are manufactured from high-tensile-strength polyester or Nylon fabrics coated with thermoplastic polyurethane (TPU), or polyvinyl chloride (PVC) or alloys coatings on both sides.

Erez is a world leader in the production of innovative coated textiles for a wide range of flexible storage tank applications, and for over 30 years has supplied coated technical fabrics for top-brand manufactures in the industry. All Erez products are glueable and weldable by HF and Hot Air methods and our PP-coated fabric is available in colors.

Erez products are thoroughly tested to ensure extreme resistance to chemicals, abrasion and punctures, as well as high UV stability, and offer excellent mechanical properties.  Our tank fabrics are specifically designed for storing and transporting liquids for extended periods while maintaining flexibility and durability.

Choosing a Coated Textile for Your Tank

Choosing an Erez coated fabric for your tank project is easy because Erez manufactures six certified barriers for potable applications requiring a CDL 23 rating for nearly any volume of liquid. All are certified by the major international standard-certification bodies, including the FDA, MIL-T specs, NSF/ANSI 61, WRAS, and AS/NZS 4020:2005. All NSF 61 certified manufactures and products are listed in a publicly-available online directory. View the Erez liners listing on the NSF website here.

By choosing Erez coated textiles that meet NSF 61 and other international standards, you are guaranteed the highest quality products that ensure world-wide marketability and safety for you and your end users.


Request a consultation


Share With Colleagues

Share this Post

Read More
Leave A Comment

Leave a Reply

Your email address will not be published. Required fields are marked *