Berkefeld products by Doulton are manufactured in an EPA-registered establishment.

Ultra Sterasyl Filters are NSF Certified.

What is NSF Certification of  Water Filter Systems?
In the United States, NSF International (formerly the National Sanitation Foundation) works to protect consumers by providing third-party testing, written standards, and validation of products available to the public.

The table below is a visual to help consumers understand the gravity water filter space.

Understanding NSF 42, 53, and 372 Codes

  • NSF/ANSI 42 – Drinking Water Treatment Units – Aesthetic Effects
  • NSF/ANSI 53 – Drinking Water Treatment Units – Health Effects
  • NSF/ANSI/CAN 372 – Drinking Water System Components – Lead Content

British Berkefeld Ultra Sterasyl vs Alexapure® Pro


Best Choice

British Berkefeld®

/ Doulton®



British Berkefeld® Ultra Sterasyl

Alexapure® Pro

Manufacturer Country Of Origin



NSF/ANSI 42 Accreditation

Aesthetic Effects

NSF/ANSI 53 Accreditation

Health Affects

NSF/ANSI 372 Accreditation

Lead Content

NSF/ANSI 401 Accreditation

Emerging Compounds /

Incidental Contaminants

Pour Through NSF


Micro Biological Klebsiella

Micro Biological E-coli


Chlorine Reduction

Heavy Metals Reduction

Lead Reduction

Glyphosate Reduction

Pesticide Reduction

Herbicide Reduction

Pharma Reduction

Chemical Reduction

Average Price Per Filter (Not Sets)