Holding(s) in Company

TR-1: NOTIFICATION OF MAJOR INTEREST IN SHARESi

1. Identity of the issuer or the underlying issuerof existing shares to which voting rights areattached: ii

Porvair Plc

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

An acquisition or disposal of voting rights

Yes

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

An acquisition or disposal of instruments with similar economic effect to qualifying financial instruments

An event changing the breakdown of voting rights

Other (please specify):

3. Full name of person(s) subject to thenotification obligation: iii

Impax Asset Management Group plc

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

Impax Asset Management (AIFM) Ltd

Impax Asset Management Ltd

Other shareholders

5. Date of the transaction and date onwhich the threshold is crossed orreached: v

06 March 2015

6. Date on which issuer notified:

10 March 2015

7. Threshold(s) that is/are crossed orreached: vi, vii

5%

8. Notified details:

A: Voting rights attached to shares viii, ix

Class/type ofshares

if possible usingthe ISIN CODE

Situation previousto the triggeringtransaction

Resulting situation after the triggering transaction

NumberofShares

NumberofVotingRights

Numberof shares

Number of votingrights

% of voting rights x

Direct

Direct xi

Indirect xii

Direct

Indirect

Ordinary Shares

GB0006963689

2,047,966

2,047,966

2,384,484

N/A

2,384,484

N/A

2,384,484

B: Qualifying Financial Instruments

Resulting situation after the triggering transaction

Type of financialinstrument

Expirationdate xiii

Exercise/Conversion Period xiv

Number of votingrights that may beacquired if theinstrument isexercised/ converted.

% of votingrights

C: Financial Instruments with similar economic effect to Qualifying Financial Instruments xv, xvi

Resulting situation after the triggering transaction

Type of financialinstrument

Exercise price

Expiration date xvii

Exercise/Conversion period xviii

Number of voting rights instrument refers to

% of voting rights xix, xx

Nominal

Delta

Total (A+B+C)

Number of voting rights

Percentage of voting rights

2,384,484

5.3220%

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

Impax Asset Management Group plc through its subsidiary companies Impax Asset Management (AIFM) Ltd

(FRN: 613534) and Impax Asset Management Ltd (FRN: 197008) acquired 336,518 shares in Porvair Plc increasing its overall holding from 4.5709% to 5.322%. These shares were purchased on behalf of a number of funds all

Proxy Voting:

10. Name of the proxy holder:

11. Number of voting rights proxy holder will ceaseto hold:

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

13. Additional information:

None

14. Contact name:

John Morrissey

15. Contact telephone number:

020 7432 2658

Note: Annex should only be submitted to the FCA not the issuer

Annex: Notification of major interests in share

A: Identity of the persons or legal entity subject to the notification obligation

Full name

(including legal form of legal entities)

Impax Asset Management Group plc

Contact address

(registered office for legal entities)

31 St James's Place, London SW1Y 4JR

Phone number & email

Other useful information

(at least legal representative for legal persons)

B: Identity of the notifier, if applicable

Full name

John Morrissey

Contact address

31 St James's Place, London SW1Y 4JR

Phone number & email

0207 432 2658

[email protected]

Other useful information

(e.g. functional relationship with the person or legal entity subject to the notification obligation)

C: Additional information

For notes on how to complete form TR-1 please see the FCA website.