U.S.Pharmacopeia Chapter 41- New USP 41 Changes

U.S. Pharmacopeia Chapter 41

How was your balance’s repeatability & accuracy changed?


In 2013 U.S. Pharmacopeia Chapter 41 for balance was revised, with the new requirements becoming mandatory December 1,2013.
Since the revision, the formula for calculating the repeatability of a balance was further revised.

The new revision in USP Chapter 41 also included a slight change in the definition. Compliance with the new requirements has become mandatory as of July 1, 2014.

What changed in USP Chapter 41?

The Formula for Repeatability in a Balance

Purpose of formula

Repeatability Formula

Previous Requirements

of USP Chapter 41

Repeatability of a balance was calculated using the nominal value of the weight used

2x standard deviation | nominal weight < 0.10%

Requirements as of July 1,2014

Repeatability of a balance is calculated using the desired smallest net weight

2x standard deviation | desired smallest net weight <

Key Reason for the Change

Key benefits for the change

The calculation change for repeatability occurred in USP Chapter 41 to resolve a question regarding the use of a balance. It is believed that it is more important to know how a balance will perform at the point of its desired smallest net weight than at the nominal weight used for measurement.

The new formula for repeatability shows us whether a balance meets the requirements at the desired smallest net weight.

The new requirements also give the users a better approach to ensuring a balances compliance.

How will this affect your work?

You know a correct way for assessing your balances accuracy and performance where it matters: at the smallest desired net weight.

All calculation sheets and certificate templates must have the new formula for repeatability as of July 1, 2014

All calibration certificates handed out prior to July 1 ,2014 will still be considered valid until next calibration period is due for your balance

USP Chapter 41 certificates from The Scale People

Key benefits of our calibration certificates

All certificates for balance calibration from the Scale People are compliant with latest revision to U.S. Pharmacopeia Chapter 41.

Please visit www.usp.org for more information

Our certificates are accurate and reliable according to USP Chapter 41

We will indicate to you, your balance desired smallest net weight and whether you have been operating within it

Benefits of Having a Scale & Balance Calibration & Repair Company in Maryland & Virginia

Finding a trustworthy and reliable calibration and repair company in Maryland & Virginia for the biotechnology and manufacturing industry can be hard to come by. The different regulatory organizations/institutes such as the FDA-USP, GLP, CLEA, ASTM, NIST, SQF and BRC set strict guidelines that must be carefully followed in all calibration and repair procedures. Using an ISO 9001:2008 and/or ISO 17025:2005 accredited supplier will guarantee that all of your scales, balances, and pipettes are calibrated and repaired to the specific standards set forth by your regulatory organization/institute.

What is ISO & how can I ensure it meets my regulatory requirements?
ISO or the International Organization of Standards is a non-governmental organization that represents the international standards of nearly 162 countries worldwide (ISO). The standards developed by ISO are derived from experts within each industry to ensure that all standards meet the requirements needed.

What is ISO 9001:2008 and ISO 17025:2005?
ISO 9001:2008- “sets out the criteria for a quality management system and is the only standard in the family that can be certified to (although this is not a requirement).” (ISO)

ISO 17025:2005- “specifies the general requirements for the competence to carry out tests and/or calibrations, including sampling. It covers testing and calibration performed using standard methods, non-standard methods, and laboratory-developed methods”  (ISO)

The advantage of an ISO 9001:2008 and ISO 17025:2005 accredited calibration and repair supplier

  1. Understands the industry-Having an ISO 9001:2008 and ISO 17025:2005 accredited vendor indicates that your supplier understands and supports industry recognized standards
  2. Assurance- All ISO 9001:2008 and ISO 17025:2005 accredited suppliers are subject to ongoing compliance surveillance by the ISO register. This means that the supplier is required to be up to date with all new standards enforced within each industry they work in.
  3. Quality- All suppliers accredited by ISO have made and continue to make a significant investment in resources to achieve the ISO recognition.

Regulatory Organizations/ Institutes defined
FDA-USP: Food and Drug Administration-U.S. Pharmacopeia
GLP: Good laboratory practice
CLEA: Clinical Laboratory Improvement Amendment
ASTM: American Society for Testing and Material
NIST: National Institute of Standards and Technology
SQF: Safe Quality Food Institute
BRC: British Retail Consortium

Works Cited
ISO. (n.d.). About ISO. Retrieved June 15, 2014, from ISO: http://www.iso.org/iso/home/about.htm
ISO. (n.d.). ISO 9000 – Quality managment . Retrieved June 15, 2014, from ISO: http://www.iso.org/iso/home/standards/management-standards/iso_9000.htm
ISO. (n.d.). ISO/IEC 17025:2005. Retrieved June 15, 2014, from ISO: http://www.iso.org/iso/home/store/catalogue_tc/catalogue_detail.htm?csnumber=39883