Domestic Water Treatment Approval Scheme Audit Procedure

A ‘Primary’ DWTAS chemical approved by the Technical Assessment Panel (TAP) on behalf of the BuildCert Advisory Committee will be granted a ‘Licence’ for a period of 5 years. Additional factored brands (secondary approval) are licensed for the remaining period of the original licence. 

1. Scope of audits.

All Primary and factored products (chemical inhibitors) shall be audited twice or as appropriate within the ‘Licence’ period.

a)         Primary certificate are issued for 5 years.

b)         All other products (secondary) based upon the ‘Primary’ product are limited to the same licence period as the ‘Primary’.

c)         All licensed products must undergo ancillary audits – 2 no. in 5 years (dependant on remaining master products licence life).

d)         Instructions for use are assessed for continued compliance.

e)         All products are to be audited to ensure continued compliance with the ‘DWTA Industry Standard for the performance of Chemical Inhibitors for use in Domestic Hot Water Central Heating Systems.

2. Selection of products for auditing

Licensees will be notified at the time of the annual membership that the Scheme requires a test report detailing the results of the audit test within the next 12 months.

Three samples (containers) shall be selected by BuildCert. 3 batches from a minimum sample batch size of 30 from the manufacturer’s or the factor’s in-house ‘off the shelf stock’.  A representative of the test laboratory, a TAP committee member, or an independent third party shall select the products for test.  Test samples selected shall be kept under the possession and control of the person making the selection and packaged and sealed in their presence and forwarded to BuildCert.  A letter documenting the person(s) making the selection and verifying the chain of custody of the samples must be forwarded to BuildCert for inclusion within the test file.

BuildCert will forward one sample to the test house for audit testing.

3. Audit test

The following test and verifications will constitute the audit of an approved chemical: -

a)      No change to the formulation (written statement required)

b)      Instructions for use continue to comply with the Schemes requirements

c)      Performance test from the DWTA Industry Standard for the performance of chemical inhibitors for use in domestic premises undertaken on one sample only, chosen at random from the three selected samples: -

• Corrosion Rate Determination

The cost for the audit testing must be negotiated with the DWTAS approved test laboratories.

The results of all audit tests along with the audited sample will be submitted to the TAP Committee (if appropriate) for verification.

The Scheme shall keep an audited sample. Where the audit on the first sample is successful, the remaining sample will be released by BuildCert for collection by the Licensee.

4. Failure of an audit test

If a sample fails the audit performance test, the test house will inform the licensee and BuildCert immediately, and the remaining two samples may then be audited tested (see notes below). 

Notes

1)      The Licensee may decide, after consideration, that the failure was an isolated incident in which case he can instruct the test house to undertake the Audits using the two remaining samples held by the Test House at the license holder's expense. If the samples subsequently pass the retest, then the chemical will be deemed to comply with the DWTAS requirements and the results will be submitted to the TAP Committee (as appropriate) for approval.

2)      Alternatively, the Licensee will provide a written assessment to TAP, which includes a description of the fault, their remedy to overcome it, the timescale to solve the problem and its effect on, and their intentions concerning, the existing population of affected products.

3)      If the TAP Committee disagree with the proposals the manufacturer will be notified and given the opportunity to provide an alternative proposal.

4)      If the TAP Committee further rejects the proposal from the manufacturer, then the Licensee will be informed and the Audit will continue using the two samples already held by the Test House.

5)      If the TAP Committee accepts the proposal (original or final) from the manufacturer, then the manufacturer will be informed and be required to provide a further random sample from new stock. The standard audit tests will then be undertaken.

If 2 audit results (in total) identify a failure then BuildCert will require full retesting to be undertaken and the TAP has received and accepted a full explanation for the audit failures.

If 3 audit results (in total) identify a failure then BuildCert will suspend the approval licence until a positive result for full retesting is received and the TAP has received and accepted a full explanation for the audit failures.  The licence holder must also detail actions to address the issue of defective stock in the market place.

5. Failure of other requirements

Failure to comply with the requirements of 5a) will require full re-testing and suspension of the licence until such time that the new formulation can be shown to fully comply with the Schemes requirements a new licence number will then be issued.  Failure to comply with 5b) will require the licence holder to amend their instructions of use.

a)         No change to the formulation.

b)         Instructions for use continue to comply with the Scheme’s requirements.

BuildCert will invoice companies involved with failed audits for time required to deal with the audit failure at the Scheme’s professional rate. 

6. Notification of Result

a)  Pass: The Licensee will be notified formally that his Chemical has passed the audit.

b)  1 Failure: The Licensee will be notified formally in writing that his chemical has failed the audit and be asked how they wish to progress the audit (see 4. Notes).

c)  2 Failures: The Licensee will be notified formally in writing that his chemical has failed two audit tests and be asked how they wish to progress the audit (see 4. Notes).

The Licensee will be requested to acknowledge, in writing his intention:

i. To submit for full testing, or
ii. Not to resubmit, in which case, the ‘Licence’ will be withdrawn immediately.

iii.Give an explanation as to why production samples of the additive are now failing the audit test

d) 3 Failures: The Licensee will be notified formally in writing that his chemical has failed three audits and that the ‘Licence’ has been suspended.

The Licensee will be requested to acknowledge, in writing his intention:

i. To submit for full testing, or

ii. Not to resubmit, in which case, the ‘Licence’ will be withdrawn immediately.