Warrant

Warrant No. W-1

by Thermatrix Inc
March 12th, 1999

 
                                                                   EXHIBIT 10.12
 
THESE WARRANTS HAVE NOT BEEN REGISTERED UNDER THE FEDERAL OR APPLICABLE STATE
SECURITIES LAWS AND INSTEAD ARE BEING ISSUED PURSUANT TO EXEMPTIONS CONTAINED
IN SAID LAWS. THE WARRANTS REPRESENTED BY THIS CERTIFICATE MAY NOT BE
TRANSFERRED UNLESS (1) A REGISTRATION STATEMENT WITH RESPECT TO SUCH WARRANTS
AND THE SHARES UNDERLYING SUCH WARRANTS SHALL BE EFFECTIVE UNDER THE
SECURITIES ACT OF 1933 OR (2) THERMATRIX INC. SHALL HAVE RECEIVED AN OPINION
OF COUNSEL REASONABLY SATISFACTORY TO IT THAT NO VIOLATION OF SUCH ACT OR
SIMILAR STATE ACTS WILL BE INVOLVED IN SUCH TRANSFER.


                                                  Warrant No. W-1
 

                                   Warrant

                     To Purchase Shares of Common Stock,

                          Par Value $.001 Per Share

                                     of
 
                               Thermatrix Inc.


          This is to Certify That Wexford Management LLC, or such holder's
registered assigns (the "Investor"), is the owner of 450,000 Warrants (as
defined below), each of which entitles the registered holder thereof to purchase
from Thermatrix Inc., a Delaware corporation (the "Company"), one fully paid,
duly authorized and nonassessable share of Common Stock, par value $.001 per
share, of the Company (the "Common Stock"), at any time or from time to time on
or before 5:00 p.m., New York City time, on February 25, 2004, at an exercise
price equal to the lesser of (x) $3.875 per share and (y) the average closing
price of the Common Stock as reported by the Nasdaq National Market for the ten
trading days immediately following the Issue Date; provided, that if there were
no sales of the Common Stock on any such date, the simple average of the highest
bid and lowest asked prices for the Common Stock on such date shall be used in
place of a closing price for such date in calculating such ten-day average (such
lesser price, the "Exercise Price"), all on the terms and subject to the
conditions hereinafter set forth.  As soon as practicable after such ten-day
period has expired, the Investor shall calculate the Exercise Price and submit
such calculation to the Company for its approval, whereupon such calculation
shall be attached hereto as Exhibit A and shall be incorporated herein by
reference.

          The number of shares of Common Stock issuable upon exercise of each
such Warrant (the "Number Issuable"), which is initially one (1) share, is
subject to adjustment from time to time pursuant to the provisions of Section 2
of this Warrant Certificate.

 
          Capitalized terms used herein but not otherwise defined shall have the
meanings given them in Section 14 hereof.

          Section 1.  Exercise of Warrant.  (a)  The Warrants evidenced hereby
                      -------------------                                     
may be exercised, in whole or in part, by the registered holder hereof at any
time or from time to time on or before 5:00 p.m., New York City time, on
February __, 2004, upon delivery to the Company at the principal executive
office of the Company in the United States of America, of (a) this Warrant
Certificate, (b) a Notice of Exercise substantially in the form attached hereto
as Exhibit B and (c) unless the holder is exercising the conversion right set
forth in Section 3,  payment of the Exercise Price for the shares of Common
Stock issuable upon exercise of such Warrants, which shall be payable by a
certified or official bank check payable to the order of the Company, or
(collectively, the "Warrant Exercise Documentation").

          As promptly as practicable, and in any event within five Business Days
after receipt of the Warrant Exercise Documentation, the Company shall deliver
or cause to be delivered (a) certificates representing the number of validly
issued, fully paid and nonassessable shares of Common Stock specified in the
Warrant Exercise Documentation, (b) if applicable, cash in lieu of any fraction
of a share, as hereinafter provided, and (c) if less than the full number of
Warrants evidenced hereby are being exercised, a new Warrant Certificate or
Certificates, of like tenor, for the number of Warrants evidenced by this
Warrant Certificate, less the number of Warrants then being exercised.  Such
exercise shall be deemed to have been made at the close of business on the date
of delivery of the Warrant Exercise Documentation so that the Person entitled to
receive shares of Common Stock upon such exercise shall be treated for all
purposes as having become the record holder of such shares of Common Stock at
such time.  No such surrender shall be effective to constitute the Person
entitled to receive such shares as the record holder thereof while the transfer
books of the Company for the Common Stock are closed for any purpose (but not
for any period in excess of five Business Days); but any such surrender of this
Warrant Certificate for exercise during any period while such books are so
closed shall become effective for exercise immediately upon the reopening of
such books, as if the exercise had been made on the date this Warrant
Certificate was surrendered and for the Number Issuable of Common Stock
specified in the Warrant Exercise Documentation and at the Exercise Price.

          The Company shall pay all expenses in connection with, and all taxes
and other governmental charges (other than income taxes of the holder) that may
be imposed in respect of, the issue or delivery of any shares of Common Stock
issuable upon the exercise of the Warrants evidenced hereby.  The Company shall
not be required, however, to pay any tax or other charge imposed in connection
with any transfer involved in the issue of any certificate for shares of Common
Stock in any name other than that of the registered holder of the Warrants
evidenced hereby.

          In connection with the exercise of any Warrants evidenced hereby, no
fractions of shares of Common Stock shall be issued, but in lieu thereof the
Company shall pay a cash adjustment in respect of such fractional interest in an
amount equal to such fractional interest multiplied by the Current Market Price
per share of Common Stock on the Business Day which 

                                       2

 
next precedes the day of exercise. If more than one such Warrant shall be
exercised by the holder thereof at the same time, the number of full shares of
Common Stock issuable on such exercise shall be computed on the basis of the
total number of Warrants so exercised.

          Section 2.  Adjustments.
                      ----------- 

                 (a)  Adjustment of Number Issuable.  The Number Issuable shall 
                      -----------------------------   
be subject to adjustment from time to time as follows:

                 (i)  In case the Company shall at any time or from time to time
     after the Issue Date:

                          (A)   pay a dividend or make a distribution on the
     outstanding shares of Common Stock in capital stock of the Company;

                          (B)   subdivide the outstanding shares of Common Stock
     into a larger number of shares;

                          (C)   combine the outstanding shares of Common Stock
     into a smaller number of shares; or

                          (D)   issue any shares of its capital stock in a
     reclassification of the Common Stock;


     then, and in each such case (other than a dividend or distribution received
     by or set aside for the benefit of the holder pursuant to Section 2(c)
     hereof), the Number Issuable in effect immediately prior to such event
     shall be adjusted (and any other appropriate actions shall be taken by the
     Company) so that the holder of any Warrant evidenced hereby thereafter
     exercised shall be entitled to receive the number of shares of Common Stock
     or other securities of the Company which such holder would have owned or
     had been entitled to receive upon or by reason of any of the events
     described above, had such Warrant been exercised immediately prior to the
     happening of such event and the Exercise Price shall be adjusted
     accordingly.  An adjustment made pursuant to this clause (i) shall become
     effective retroactively (x) in the case of any such dividend or
     distribution, to a date immediately following the close of business on the
     record date for the determination of holders of shares of Common Stock
     entitled to receive such dividend or distribution, or (y) in the case of
     any such subdivision, combination or reclassification, to the close of
     business on the date upon which such corporate action becomes effective.

               (ii)  The Company promptly shall deliver to each registered
     holder of Warrants prior to effecting any transaction which would result in
     an increase or decrease in the Number Issuable pursuant to this Section 2 a
     notice thereof, together with a certificate, signed by the Chief Executive
     Officer or a Vice-President and by the Treasurer or an Assistant Treasurer
     or the Secretary or an Assistant Secretary of the 

                                       3

 
     Company, setting forth in reasonable detail the event requiring the
     adjustment and the method by which such adjustment was calculated and
     specifying the increased or decreased Number Issuable then in effect
     following such adjustment.

               (iii)  Notwithstanding anything contrary contained in this
     Section 2(a), the Company shall be entitled to make such upward adjustments
     in the Number Issuable, in addition to those otherwise required by this
     Section 2(a), as the Board of Directors of the Company in their discretion
     shall determine to be advisable in order that any stock dividend,
     subdivision or combination of shares, distribution of rights or warrants to
     purchase stock or securities, or distribution of securities convertible
     into or exchangeable for Common Stock, hereafter made by the Company to its
     shareholders shall not be taxable; provided, however, that any such
                                        --------  -------               
     adjustment shall be made, as nearly as practicable, in a manner which
     treats all holders of Warrants with similar protections on an equal basis.

               (b)   Reorganization, Reclassification, Consolidation, Merger 
                     -------------------------------------------------------
or Sale of Assets.  In case of any capital reorganization or reclassification 
- ----------------- 
or other change of outstanding shares of Common Stock (other than a change in
par value, or from par value to no par value, or from no par value to par
value, or as a result of a subdivision or combination), or in case of any
consolidation or merger of the Company with or into another Person (other than
a consolidation or merger in which the Company is the resulting or surviving
person and which does not result in any reclassification or change of
outstanding Common Stock), or in case of any sale or other disposition to
another Person of all or substantially all of the assets of the Company (any
of the foregoing, a "Transaction"), the Company, or such successor or
purchasing Person, as the case may be, shall execute, make lawful provision
for and deliver to each holder of the Warrants evidenced hereby, prior to
effecting any of the foregoing Transactions, a certificate that the holder of
each such Warrant then outstanding shall have the right thereafter to exercise
such Warrant into the kind and amount of shares of stock or other securities
(of the Company or another issuer) or property or cash receivable upon such
Transaction by a holder of the number of shares of Common Stock into which
such Warrant could have been exercised immediately prior to such Transaction.
Such certificate shall provide for adjustments which shall be as nearly
equivalent as may be practicable to the adjustments provided for in this
Section 2 and shall contain other terms identical to the terms hereof.

               (c)   Special Distributions.  If the holder so elects by sending 
                     ---------------------   
a Special Notice to the Company, in the event that the Company shall declare a
dividend or make any other distribution (including, without limitation, in
cash, in capital stock (which shall include, without limitation, any options,
warrants or other rights to acquire capital stock) of the Company, whether or
not pursuant to a shareholder rights plan, "poison pill" or similar
arrangement) in other property or assets, to holders of Common Stock (a
"Special Distribution"), then the Board of Directors shall promptly distribute
to the holder the amount of such dividend or distribution that any holder of
Warrants would have been entitled to receive had it exercised such Warrants
prior to the record date for such dividend or distribution. If the holder so
elects by sending a Special Notice to the company, then the Board of Directors
shall set aside such amount of such dividend or distribution, and upon the
exercise of a Warrant evidenced hereby, the holder shall be 

                                       4

 
entitled to receive, such dividend or distribution that such holder would have
received had such Warrant been exercised immediately prior to the record date
for such dividend or distribution. Prior to any Special Distribution described
in this Section 2(c), the Company shall as provided in Section 4 hereof notify
each holder (prior to the occurrence of each Special Distribution) of its
intent to make such Special Distribution and the holder, if it elects to have
such distribution set aside the amount thereof rather than have an adjustment
to the Number Issuable as provided in Section 2(a)(i), 2(a)(ii) or 2(a)(iii),
shall notify the Company by sending a Special Notice prior to the date of any
such Special Distribution.

          Section 3.  Conversion Right. In lieu of exercising this Warrant as
                      ----------------                                       
specified in Section 1,  the holder may from time to time convert this Warrant,
in whole or in part, into a number of shares determined by dividing (a) the
aggregate Current Market Price of the shares or other securities otherwise
issuable upon exercise of this Warrant minus the aggregate Exercise Price of
such shares by (b) the Current Market Price of one share.

          Section 4.  Redemption.  The Company shall not have any right to
                      ----------                                          
redeem any of the Warrants evidenced hereby.

          Section 5.  Notice of Certain Events.  In case at any time or from
                      ------------------------                              
time to time the Company shall declare any dividend or any other distribution to
the holders of its Common Stock, or shall authorize the granting to the holders
of its Common Stock of rights or warrants to subscribe for or purchase any
additional shares of stock of any class or any other right, or shall authorize
the issuance or sale of any other shares or rights which would result in an
adjustment to the Number Issuable pursuant to Section 2(a)(ii) or would result
in a Special Distribution pursuant to Section 2(c), or there shall be any
Transaction, or there shall be a voluntary or involuntary dissolution,
liquidation or winding up of the Company, then, in any one or more of such cases
the Company shall mail to each holder of the Warrants evidenced hereby at such
holder's address as it appears on the transfer books of the Company, as promptly
as practicable but in any event at least 30 days prior to the applicable date
hereinafter specified, a notice stating (a) the date on which a record is to be
taken for the purpose of such dividend, distribution, rights or warrants or, if
a record is not to be taken, the date as of which the holders of Common Stock of
record to be entitled to such dividend, distribution, rights or warrants are to
be determined, (b) the date of issuance thereof or (c) the date on which such
Transaction, dissolution, liquidation or winding up is expected to become
effective; provided that in the case of any event to which Section 2(b) applies,
           --------                                                             
(i) the Company shall give prior written notice as aforesaid and (ii) such
notice also shall specify the date as of which it is expected that the holders
of Common Stock of record shall be entitled to exchange their Common Stock for
shares of stock or other securities or property or cash deliverable upon such
reorganization, reclassification, consolidation, merger, sale, conveyance,
dissolution, liquidation or winding up.

          Section 6.  Certain Covenants.  The Company covenants and agrees that
                      -----------------                                        
all shares of capital stock of the Company which may be issued upon the exercise
of the Warrants evidenced hereby will be duly authorized, validly issued and
fully paid and nonassessable.  The Company shall at all times reserve and keep
available for issuance upon the exercise of the Warrants, such number of its
authorized but unissued shares of Common Stock as will from time 

                                       5

 
to time be sufficient to permit the exercise of all outstanding Warrants, and
shall take all action required to increase the authorized number of shares of
Common Stock if at any time there shall be insufficient authorized but
unissued shares of Common stock to permit such reservation or to permit the
exercise of all outstanding Warrants.

Section 7.  Investor Consent Required.  If the Company or any subsidiary has any
            -------------------------                                           
outstanding Obligations (as such term is defined in the Second Amended and
Restated Credit Agreement, dated February __, 1999, among the Investor as Agent,
the Lenders named therein, the Company and Wahlco Environmental Systems, Inc.
(the "Credit Agreement")), the Company shall not without the Investor's consent
issue any equity security, or any note, debenture, bond or other debt or equity
security convertible or exchangeable into, or grant any option, warrant or
similar right that upon exercise would provide the right to purchase, any shares
of stock (of any class or series) of the Company without the Investor's consent,
if such security contains anti-dilution protections that are more favorable than
those provided in Section 2 hereof.   Notwithstanding the foregoing, the
Investor's consent shall not be required for such issuance if the Company has
amended the terms of Section 2 so as to provide the Investor with anti-dilution
protections at least as favorable as such more favorable terms; provided,
however, that the Exercise Price shall not be adjusted as a result of such
issuance or grant but may be adjusted as a result of subsequent issuances or
grants in accordance with the terms of such amended anti-dilution protections.

          Section 8.  Registered Holder.  The person in whose name this Warrant
                      -----------------                                        
Certificate is registered shall be deemed the owner hereof and of the Warrants
evidenced hereby for all purposes.

          Section 9.  Transfer of Warrants.  Any transfer of the rights
                      --------------------                             
represented by this Warrant Certificate shall be effected by the surrender of
this Warrant Certificate, along with the form of assignment attached Exhibit C
hereto, properly completed and executed by the registered holder hereof, at the
principal executive office of the Company in the United States of America;
provided that (a) a registration statement with respect to the Warrants proposed
for transfer, and with respect to the shares of Common Stock underlying such
Warrants, shall be effective under the Securities Act or (b) the Company shall
have received an opinion of counsel reasonably satisfactory to it that no
violation of such act or similar state acts will be involved in such transfer.
Thereupon, the Company shall issue in the name or names specified by the
registered holder hereof and, in the event of a partial transfer, in the name of
the registered holder hereof, a new Warrant Certificate or Certificates
evidencing the right to purchase such number of shares of Common Stock as shall
be equal to the number of shares of Common Stock then purchasable hereunder.
Each such Certificate shall bear a legend as to the applicable restrictions on
transferability in order to insure compliance with the Securities Act, unless in
the aforesaid reasonably satisfactory opinion of counsel for the Holder or the
security holder, as the case may be, such legend is not necessary in order to
insure compliance with the Securities Act. The Holder shall not transfer this
warrant to a Competitor of the Company.

          Section 10.  Denominations.  The Company covenants that it will, at
                       -------------                                         
its expense, promptly upon surrender of this Warrant Certificate at the
principal executive office of the Company in the United States of America,
execute and deliver to the registered holder hereof a 

                                       6

 
new Warrant Certificate or Certificates in denominations specified by such
holder for an aggregate number of Warrants equal to the number of Warrants
evidenced by this Warrant Certificate.

          Section 11.  Replacement of Warrants.  Upon receipt of evidence
                       -----------------------                           
satisfactory to the Company of the loss, theft, destruction or mutilation of
this Warrant Certificate and, in the case of loss, theft or destruction, upon
delivery of an indemnity reasonably satisfactory to the Company (in the case of
an institutional investor, its own unsecured indemnity agreement shall be deemed
to be reasonably satisfactory), or, in the case of mutilation, upon surrender
and cancellation thereof, the Company will issue a new Warrant Certificate of
like tenor for a number of Warrants equal to the number of Warrants evidenced by
this Warrant Certificate.

          Section 12.  Governing Law.  THIS WARRANT CERTIFICATE SHALL BE
                       -------------                                    
GOVERNED BY AND CONSTRUED IN ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK
(WITHOUT GIVING EFFECT TO ANY CHOICE OR CONFLICT OF LAW PROVISIONS).

          Section 13.  Rights Inure to Registered Holder.  The Warrants
                       ---------------------------------               
evidenced by this Warrant Certificate will inure to the benefit of and be
binding upon the registered holder thereof and the Company and their respective
successors and permitted assigns.  This Warrant Certificate shall be for the
sole benefit of the registered holder thereof.  Nothing in this Warrant
Certificate shall be construed to give the registered holder hereof any rights
as a holder of shares of Common Stock until such time, if any, as the Warrants
evidenced by this Warrant Certificate are exercised or converted in accordance
with the provisions hereof.

          Section 14.  Definitions.  For the purposes of this Warrant
                       -----------                                   
Certificate, the following terms shall have the meanings indicated below:

          "Business Day" shall mean any day other than a Saturday, Sunday or
           ------------                                                     
other day on which commercial banks in the City of New York are authorized or
required by law or executive order to close.

          "Common Stock" shall have the meaning assigned to such term in the
           ------------                                                     
Preamble hereof.

          "Company" shall have the meaning assigned to such term in the Preamble
           -------                                                              
hereof.

          "Competitor of the Company" shall mean a company engaged in the
           -------------------------                                     
design, development, manufacture and/or sale of (i) equipment or systems used to
control or destroy air emissions including, but not limited to, particulate
matter ("PM"), oxides of nitrogen ("NOx") and volatile organic compounds and
hazardous air pollutants (collectively "VOCs"); (ii) gas flow diverters, dampers
and expansion joints used to control the flow of air and gases in power
generation and industrial facilities; or (iii) equipment or systems used to
control emissions from stationary and/or mobil diesel engines, and, in each
case, (iv) generates revenues of $3 million per annum from such business or
businesses.

                                       7

 
          "Current Market Price" per share shall mean, on any date specified
           --------------------                                             
herein for the determination thereof, (a) if the Common Stock is then listed on
a national securities exchange, designated as a Nasdaq Stock Market security or
quoted in the over-the-counter-market by a member firm of the NASD, the average
daily Market Price of the Common Stock for those days during the period of 15
days, ending on such date, on which the national securities exchanges were open
for trading, and (b) if the Common Stock is not then so listed, designated or
quoted, the Market Price on such date.

          "Exercise Price" shall have the meaning assigned to such term in the
           --------------                                                     
Preamble hereof.

          "Fair Market Value" shall mean the amount which a willing buyer, under
           -----------------                                                    
no compulsion to buy, would pay a willing seller, under no compulsion to sell,
in an arm's-length transaction.

          "Investor" shall have the meaning assigned to such term in the
           --------                                                     
Preamble hereof.

          "Issue Date" shall mean February 25, 1999.
           ----------                               

          "Market Price" shall mean, per share of Common Stock, on any date
           ------------                                                    
specified herein: (a) if the Common Stock is listed on any national securities
exchange or is designated as a Nasdaq Stock Market security, the last trading
price of the Common Stock on such date as reported in the Wall Street Journal;
or (b) if the Common Stock is not so listed or designated, the average of the
reported closing bid and ask prices of the Common Stock in the over-the-counter-
market, on such date as reported by any member firm of the NASD selected by the
Company; or (c) if none of (a) or (b) is applicable, the Fair Market Value per
share determined in good faith by the Board of Directors of the Company which
shall be deemed to be Fair Market Value unless holders of at least 50% of Common
Stock issued or issuable upon exercise of the Warrants request that the Company
obtain an opinion of a nationally recognized public accounting firm chosen by
the Company (who shall bear the expense) and reasonably acceptable to such
requesting holders of the Warrants, in which event the Fair Market Value shall
be as determined by such investment banking firm.

          "Number Issuable" shall have the meaning assigned to such term in the
           ---------------                                                     
Preamble hereof.

          "Person" shall mean any individual, corporation, limited liability
           ------                                                           
company, partnership, trust, incorporated or unincorporated association, joint
venture, joint stock company, government (or an agency or political subdivision
thereof) or other entity of any kind.

          "Securities Act" shall mean the Securities Act of 1933.
           --------------                                        

          "Special Distribution" shall have the meaning assigned to such term in
           --------------------                                                 
Section 2(c) hereof.

                                       8

 
          "Special Notice" shall mean the notice sent by a holder to the Company
           --------------                                                       
indicating its preference to have any Special Distribution distributed
immediately or set aside for its benefit upon exercise of the Warrant.

          "Transaction" shall have the meaning assigned to such term in Section
           -----------                                                         
2(b) hereof.

          "Warrants" shall have the meaning assigned to such term in the
           --------                                                     
Preamble hereof.

          "Warrant Exercise Documentation" shall have the meaning assigned to
           ------------------------------                                    
such term in Section 1 hereof.

          Section 15.  Notices.  All notices, requests and other communications
                       -------                                                 
provided for or permitted hereunder shall be in writing and sufficient if
delivered personally or sent by telecopy (with confirmation of receipt) or by
registered or certified mail, postage prepaid, return receipt requested, (a) if
to the holder of a Warrant, at such holder's last known address or telecopy
number appearing on the books of the Company; and (b) if to the Company, at its
principal executive office, or the telecopy number of such office, in the United
States, or such other address or telecopy number as the party to whom notice is
to be given may have furnished to the other party in accordance herewith.  Each
such notice, request or communication shall be effective when received or, if
given by mail, when delivered at the address specified in this Section or on the
fifth Business Day following the date on which such communication is posted,
whichever occurs first.

          Section 16.  Share Legend.  Each certificate representing shares of
                       ------------                                          
Common Stock or any other securities issued upon exercise of this Warrant shall
bear the following legend unless such shares or other securities have been
registered under the Securities Act and any applicable state securities laws:

          "THESE SHARES HAVE NOT BEEN REGISTERED UNDER THE FEDERAL OR APPLICABLE
STATE SECURITIES LAWS AND INSTEAD ARE BEING ISSUED PURSUANT TO EXEMPTIONS
CONTAINED IN SAID LAWS.  THE SHARES REPRESENTED BY THIS CERTIFICATE MAY NOT BE
TRANSFERRED UNLESS (A) A REGISTRATION STATEMENT SHALL BE EFFECTIVE UNDER THE
SECURITIES ACT OF 1933 OR (B) THERMATRIX INC. SHALL HAVE RECEIVED AN OPINION OF
COUNSEL REASONABLY SATISFACTORY TO IT THAT NO VIOLATION OF SUCH ACT OR SIMILAR
STATE ACTS WILL BE INVOLVED IN SUCH TRANSFER."

                                       9

 
     In Witness Whereof, the Company has caused this Warrant Certificate to be
duly executed as of the Issue Date.


                              Thermatrix Inc.



                              By: /s/ Daniel S. Tedone
                                 ------------------------------------
                                 Name:  Daniel S. Tedone
                                 Title: Executive Vice President
                                        and Chief Financial Officer

                                       10

 
                                                                       Exhibit A
                                                                      To Warrant


                       [Calculation of Exercise Price]


The Exercise Price for the Warrant is $_____________ per share of Common Stock.

The Exercise Price was calculated as follows:





Accepted and Agreed

Thermatrix Inc.

By:__________________________________ 
   Name:  Daniel S. Tedone
   Title: Executive Vice President
          and Chief Financial Officer


 
                                                                       Exhibit B
                                                                      to Warrant
                                                                                
                        [Form of Notice of Exercise]
                                        
To:  Thermatrix Inc.

     (1)   The undersigned hereby elects to purchase _______________ shares of
Common Stock of Thermatrix Inc. pursuant to the terms of the attached Warrant,
and

       [_]    tenders payment of the purchase price in full, together with all
       applicable transfer taxes, if any;

       [_]    elects to exercise its conversion right pursuant to Section 3
       thereof.

     (2)   Please issue a certificate of certificates representing said shares
of Common Stock in the name of the undersigned.

     (3)   The undersigned represents and warrants:

           (a)   that the aforesaid shares of Common Stock are being acquired
for the account of the undersigned for investment and not with a view to, or
for resale in connection with, the distribution thereof and that the
undersigned has no present intention of distributing or reselling such shares.

           (b)   that the undersigned is aware of the Company's business affairs
and financial condition and has acquired sufficient information about the
Company to reach an informed and knowledgeable decision to acquire the Common
Stock.

           (c)   that the undersigned acknowledges and understands that the
Common Stock constitutes "restricted securities" under the Securities Act and
has not been registered under the Securities Act in reliance upon a specific
exemption therefrom. The undersigned further acknowledges and understands that
the Company is under no obligation to register the Common Stock except as
described in the Registration Rights Agreement between the Company and Wexford
Management LLC, dated February __, 1999. The undersigned understands that the
certificate evidencing the Common Stock will be imprinted with a legend which
prohibits the transfer of the Common Stock unless they are registered or such
registration is not required in the opinion of counsel satisfactory to the
Company; and

           (d)   that the undersigned is familiar with the provisions of Rule
144, promulgated under the Securities Act. The undersigned further understands
that in the event all of the applicable requirements of Rule 144 are not
satisfied, registration under the Securities Act, some other registration
exemption will be required for transfer of the Securities.

     (Date)                         (Signature)


 
                                                                       Exhibit C
                                                                      To Warrant


                          [Form of Assignment Form]

                [To be executed upon assignment of Warrants]

          The undersigned hereby assigns and transfers this Warrant Certificate
to ____________________ whose Social Security Number or Tax ID Number is
_________________ and whose record address is
_____________________________________, and irrevocably appoints ________________
as agent to transfer this security on the books of the Company.  Such agent may
substitute another to act for such agent.

                               Signature:



                               ____________________________________



Date: ___________________________