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Leakproofness testing of aerosols filled in the UK

Arrangements for the approval of alternatives to the hot water bath method.

Aerosol dispensers and small receptacles containing compressed gas (gas cartridges) which are filled, transported or placed on the market in the UK must pass an leakproofness test before they are offered for carriage.  This is a requirement of both the EC Aerosol Dispensers Directive (75/324/EEC) and the Carriage of Dangerous Goods and Use of Transportable Pressure Equipment Regulations (CDG), the latter by reference to the European Agreement on the Transport of Dangerous Goods by Road (ADR). Certain types of sterile pharmaceutical aerosols containing non-flammable gas are exempt from this requirement but these are few in number.

Both ADR and the Aerosol Dispensers Directive require impermeability to be determined by immersing each aerosol or gas cartridge in a hot water bath and inspecting it for leakage; a task usually accomplished by the filler of the receptacle immediately after it has been pressurised.  However, since publication of the 2007 revision of ADR, National Competent Authorities may authorise the use of alternatives to the hot water bath method for aerosol dispensers (but not gas cartridges), providing an equivalent level of safety is maintained. One alternative method, developed by the European Aerosol Federation (FEA), is described in their "Guide on Hot Water Bath Testing Alternatives", published June 2008.  It has been shown that the integrated test and quality assurance system set out in that guide, when properly implemented, is capable of meeting the relevant requirements of ADR ₍₁₎.

The Dangerous Goods Division of the Department for Transport (DfT) performs the functions of the Competent Authority for the United Kingdom on behalf of the Secretary of State for Transport.  The Department has established procedures to authorise those companies engaged in the filling of aerosols to operate an alternative leakproofness test system, in accordance with the requirements of ADR, should they so require. The authorisation programme is operated by the Dangerous Goods Office of the VCA, an executive agency of the DfT.
 
Companies seeking authorisation in the UK are strongly advised to implement a quality assurance system meeting the requirements of Annex C. of the FEA guide, since this method has already been validated. Other equally effective systems may be considered, but a comprehensive technical validation programme will be required to demonstrate parity with the hot water bath method before any could be approved. This is likely to be far more costly and time-consuming than implementing the FEA system.

Normally, when the FEA guidance is followed it will only be necessary to ascertain that the company's implementation of it incorporates all of the essential features and that it is operating effectively. In this case, authorisation may be granted for the use of individually identifiable leakproofness test systems and specified filling lines, subject to satisfactory initial and periodic audits of the quality system. Audits will be performed by VCA or approved auditors appointed by them.

Application for the authority to use an alternative method of leak detection may be made to VCA DG at the address below. Applications must be accompanied by a copy of the Dossier of Evidence described in the FEA guidelines, together with the application fee, currently £460 plus VAT.

The dossier will be reviewed and, if satisfactory, an audit of the applicant's facilities and systems will be arranged at a mutually convenient time. An audit fee will be payable, the amount of which will depend upon the scale and location of the facility to be audited. An estimate will be provided to the applicant before the audit appointment is confirmed.

If the Dossier of Evidence, or the processes it describes, are deficient in some way, an audit will not be offered. Instead, VCA will inform the applicant of any areas that appear to require attention before an audit can take place. To ensure impartiality is maintained, VCA can not offer the applicant any more than general guidance on corrective actions. If technical assistance with the rectification of deficiencies is required, it must be sought elsewhere. When the applicant believes all of the issues have been adequately addressed, the dossier may be resubmitted to VCA, who may make an additional charge if significant work is involved in re-evaluating it. An audit will be offered when the dossier is considered adequate.
 
At the initial audit the major aspects of the quality system will be scrutinised,  including, but not limited to:

• The organisational structure and management responsibilities for ensuring compliance with the FEA guidance;
• Records of external audits performed on the QA system of each actor in the supply chain (except those holding current accreditation to ISO 9000 for the product or material supplied);
• The aerosol can supplier's policy and procedures for pressure and leak testing empty aerosol bodies;
• Evidence of the leak detector's performance, stability and suitability for purpose together with independently verified proof of  its ability to reliably and consistently detect leakage at the level specified in ADR;
• Documented procedures for
  • handling components and finished material;
  • setting-up, operating and checking the aerosol filling equipment;
  • check-weighing filled aerosols;
  • leak testing filled aerosols;
  • in-service calibration of the check-weigher and leak tester.
  • Inspection reports, certificates of conformity, test data, calibration data, and certificates;
  • Records of internal audits carried out periodically to check that procedures are being followed correctly, that critical issues are identified and resolved in a timely manner and that the system overall remains effective.

If the system fails to meet the requirements of the guidance or regulations, or it is found not to be operating in accordance with procedures, the auditor will issue a notice of non-compliance(s) which the company must address before authorisation will be considered. In many cases, written evidence of the rectification of non-compliances will be accepted, but occasionally a supplementary site audit may be necessary, and this will incur additional cost.

When the system is considered to meet the requirements of the guidance and regulations in full, the auditor will submit a report to VCA DG, with a recommendation that authority be granted to the filler to operate that system as an alternative to the hot water bath method of leakproofness testing.

VCA will offer authorisation, subject to the company agreeing the terms and conditions of issue and if accepted, a letter of authorisation will follow.

Authorisation may be maintained subject to:

• The authorised system remaining effective and operating at an acceptable standard;
• Satisfactory results of system audits conducted:
  a. Annually, or
  b. whenever a significant change is made to equipment or systems previously subject to an audit, or
  c. before any new filling or leakproofness test equipment, required to operate under the terms of the authorisation, is used for regular production.
• Prompt payment of all fees relating to the authorisation.

The company will be required to notify VCA DG promptly of any significant changes in equipment, procedures, location or personnel.

Authorisation may be withdrawn at any time subject to 7 days written notice.

Application for approval may be made to VCA at the following address:

Aerosol Leakproofness Testing
VCA Dangerous Goods Office
Cleeve Road,
Leatherhead
Surrey
KT22 7NF

1. UN/SCETDG/24/INF.49,  Presented  to the Sub-Committee of Experts on the Transport of Dangerous Goods,  Twenty-fourth session, Geneva, 3-10 December 2003