Director/PDMR Shareholding

Tristel PLC
09 August 2006



                                  Tristel plc

                            Directors' Shareholdings


Tristel plc ('Tristel'), the healthcare business which uses its proprietary
chlorine dioxide chemistry for infection control in hospitals, in water
treatment and the food processing industry, announces that Paul Swinney, Chief
Executive, has sold 174,017 ordinary shares to Peter Stephens, a non-executive
director of Tristel, at a price of 48 pence per share.


Paul Swinney's shareholding in Tristel after the sale is 2,544,969 ordinary
shares   (10.68%) and Peter Stephens shareholding is 767,414 ordinary shares
(3.22%).


The share sale constitutes a repayment of a personal loan made to  Paul Swinney
by Peter Stephens in August 2005.  The loan was used by Paul Swinney to settle
certain tax and national insurance liabilities arising from his exercise of
2,265,475 options upon Tristel's admission to AIM on 1st June 2005.

For further information, please contact:


Tristel plc                                              Parkgreen Communications Ltd

Paul Swinney, Chief Executive                            Paul McManus
Paul Barnes, Finance Director                            Tel   [phone]
Tel:  [phone]                                      Mob: [phone]
http://www.tristel.com                                   [e-mail]


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