Holding in Company

Porvair PLC
19 March 2007



Holding in Company

1. Identity of the issuer or the underlying issuer of existing shares to which
voting rights are attached:

Porvair plc

2. Reason for the notification (please tick the appropriate box or boxes):

An acquisition or disposal of voting rights:

( X )

An acquisition or disposal of financial instruments which may result in the
acquisition of shares already issued to which voting rights are attached:

(  )

An event changing the breakdown of voting rights:

(  )

Other (please specify):

(  )

3. Full name of person(s) subject to the notification obligation:

Schroders plc

4. Full name of shareholder(s) (if different from 3.):

5. Date of the transaction (and date on which the threshold is crossed or
reached if different):

14/03/2007

6. Date on which issuer notified:

15/03/2007

7. Threshold(s) that is/are crossed or reached:

From 22% - 21%

8. Notified details:

A: Voting rights attached to shares


Class/type of shares            Situation previous to the triggering transaction
                                 
Ordinary                         Number of Shares        Number of Voting Rights
GB0006963689                            9,327,710                      9,327,710


Resulting situation after the triggering transaction

Number of shares           Number of voting rights            % of voting rights
Direct                      Direct        Indirect             Direct   Indirect
n/a                            n/a       8,896,427                n/a    21.928%


B: Financial Instruments

Resulting situation after the triggering transaction

Type of     Expiration Exercise /     Number of voting rights that may   % of
financial   date       conversion     be acquired if the instrument is   voting
instrument             period / date  exercised / converted              rights


Total (A+B):

Number of voting rights              % of voting rights
              8,896,427                         21.928%


9. Chain of controlled undertakings through which the voting rights and/or the
financial instruments are effectively held, if applicable:

Schroder Investment Management Limited      8,876,427     21.88%
Schroder & Co Limited                          20,000     0.049%


Proxy Voting:

10. Name of the proxy holder:

11. Number of voting rights proxy holder will cease to hold:

12. Date on which proxy holder will cease to hold voting rights:

13. Additional information:

The shares referred to in section 9 are held in portfolios managed by those
firms on a discretionary basis for clients under investment management
agreements.

14. Contact name:

Chris Tyler
Group Finance Director and Company Secretary
Porvair plc

15. Contact telephone number:

01553 765 500






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