1. Introduction
Filters that come into contact with food and drug products must be intrinsically safe. This means that they must not leach harmful substances into the product that they are filtering. Test requirements for filter cartridges are not specified by regulatory bodies. However the United States of America Food and Drug Administration’s Code of Federal Regulations, Title 21 Part 177 (21 CFR 177) provides a minimum standard for testing polymers, and this can be applied to the materials of construction of filter cartridges. This document is intended to provide a general outline of the procedure undertaken to ensure that, in accordance with the worst case approach adopted by domnick hunter, filter cartridge components conform to the relevant requirements of 21 CFR 177.
2. Procedure
Methods are given in the relevant sections of the Code of Federal Regulations, Title 21 ‘Food and Drugs’, Part 177 ‘Indirect Food Additives – Polymers’ for testing materials for their suitability for contact with food and drugs. These are readily available to view on the Internet at http://www.access.gpo.gov/cgi-bin/cfrassemble.cgi?title=200021. The sections describe a number of features of the materials and typically include:
- Raw material and production methods
- Identification using thermal decomposition and infra red spectroscopy
- Melting point
- Density
- Extraction tests in various solvents under given conditions
domnick hunter’s policy is to select polymers for use within filtration products which are known to comply to the relevant section of 21 CFR 177. Suppliers are requested to provide documentary evidence to support compliance with the relevant entries. Should this be unavailable then specific material testing to the methodology provided is carried out. Samples of the material are obtained. Ideally, the samples are in the finished form as used by domnick hunter, for example a moulded component such as a filter cartridge outer protection cage or a microporous membrane rather than the raw polymer pellets. The domnick hunter part number and description for the component, and the supplier batch reference, are recorded. An external laboratory is used for the purpose of testing to provide independent results. The test laboratory is selected such that the test results and conclusions meet the requirements of the international standard ISO/IEC 17025 (which replaces ISO guide 25 and EN 45001). The laboratory must also implement a quality management system that meets the requirements of ISO 9001 and 9002, for their testing and calibration activities. In the UK, UKAS accreditation covers these requirements.
Example
The test requirements for individual materials differ substantially so, as an example, a report covering the analysis of an extruded polypropylene net, used as a filter media support and spacing layer within certain pleated pack constructions, is given on the following pages. The report concludes that the polymer, in its finished component form, complies with the relevant requirements of CFR Title 21, Part 177, Section 1520 ‘Olefin polymers.
Example Test Report and Conclusions
3. Technical Support Group activities
domnick hunter have a trained team of scientists and engineers available to answer questions regarding the technical capabilities of our products, to assist in the selection and design of appropriate filtration systems and to provide user training programs. The following services can be delivered both on site and in-house;
- filterability testing to optimise filter system design
- advice on the development of integrity testing, steam sterilisation and clean in place procedures
- development of validation procedures
- troubleshooting
- facility audits to ensure continued optimisation of filter use
- operator training including filtration theory, filter system design and management, validation, etc.
For more information on any of the above support services please contact your local domnick hunter representative. email: tsg@domnickhunter.com
