Holding(s) in Company

Porvair PLC
13 July 2006



Letter to: RNS

SECTION 198 COMPANIES ACT 1985 - 3% NOTIFIABLE INTEREST

We have been advised of the following holding by Schroder Investment Management
Limited held in portfolios managed by them on a discretionary basis.

                                         
Registered owner                           No. of shares             % holding                                          
----------------                           -------------             ---------
Schroder Unit Trusts Ltd (SUTL)                5,986,294 

British Coal Staff Superannuation a/c:P        1,083,322
Chase Manhattan Bank                             389,188
Mineworkers' Pension Scheme a/c:R              1,388,906
Nortrust Nominees Limited                        480,000
                                                 -------
                                               3,341,416
                                               
                                               ---------               -------
                                               9,327,710                22.989


Letter from: Chris Tyler
             Company Secretary
             Porvair plc



                      This information is provided by RNS
            The company news service from the London Stock Exchange