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                                                                    EXHIBIT 4.10



                 FIFTH AMENDMENT TO LOAN AND SECURITY AGREEMENT


         THIS FIFTH AMENDMENT TO LOAN AND SECURITY AGREEMENT (hereinafter
referred to as the "Amendment") is made and entered into as of the 1st day of
July, 2003, between and among, on the one hand, the lenders identified on the
signature pages hereof (such lenders, together with their respective successors
and assigns, are referred to hereinafter each individually as a "Lender" and
collectively as the "Lenders"), WELLS FARGO FOOTHILL, INC., a California
corporation (f/k/a Foothill Capital Corporation), as the arranger and
administrative agent for the Lenders ("Agent"), and, on the other hand, PCI
CHEMICALS CANADA COMPANY, a Nova Scotia unlimited liability company, and PIONEER
AMERICAS LLC, a Delaware limited liability company (hereinafter each
individually is referred to as a "Borrower" and collectively as the
"Borrowers").

                                    RECITALS

         A. Agent, the Lenders and the Borrowers have entered into that certain
Loan and Security Agreement, dated as of December 31, 2001 (as amended by that
certain (i) First Amendment to Loan and Security Agreement dated as of April 15,
2002, (ii) Second Amendment to Loan and Security Agreement dated as of June 3,
2002, but effective as of May 31, 2002, (iii) Third Amendment to Loan and
Security Agreement dated as of July 29, 2002, and (iv) Fourth Amendment to Loan
and Security Agreement dated as of December 10, 2002, herein the "Agreement").

         B. Agent, the Lenders and the Borrowers desire to amend the Agreement
as hereinafter set forth.

         NOW, THEREFORE, in consideration of the premises herein contained and
other good and valuable consideration, the receipt and sufficiency of which are
hereby acknowledged, the parties, intending to be legally bound, hereby agree as
follows:

                                    ARTICLE I
                                   DEFINITIONS

         Section 1.01. Definitions. Capitalized terms used in this Amendment, to
the extent not otherwise defined herein, shall have the same meaning as in the
Agreement, as amended hereby.

                                   ARTICLE II
                                   AMENDMENTS

         Section 2.01. Amendment to Definition of Eligible Finished Goods
Inventory. The definition of "Eligible Finished Goods Inventory" in Section 1.1
of the Agreement is hereby amended by deleting "or" at the end of subparagraph
(e); deleting the period at the end of subparagraph (f) and inserting, in lieu
thereof, "; or"; and adding a subparagraph (g) thereto to read as follows:

         "(g) it consists of goods in transit to or stored at storage facilities
         pursuant to a Terminal Agreement."

         Section 2.02. Amendment to Definition of Eligible Raw Materials
Inventory. The definition of "Eligible Raw Materials Inventory" in Section 1.1
of the Agreement is hereby amended by deleting "or" at the end of subparagraph
(d); deleting the period at the end of subparagraph (e) and inserting, in lieu
thereof, "; or"; and adding a subparagraph (f) thereto to read as follows:

         "(f) it consists of goods in transit to or stored at storage facilities
         pursuant to a Terminal Agreement."


FIFTH AMENDMENT TO LOAN AND SECURITY AGREEMENT - PAGE 1

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         Section 2.03. Amendment to Definition of Foothill. The definition of
"Foothill" in Section 1.1 of the Agreement is hereby amended and restated in its
entirety to read as follows:

                  "'Foothill' means Wells Fargo Foothill, a California
         corporation (f/k/a Foothill Capital Corporation)."

         Section 2.04. Amendment to Definition of Offsite Eligible Inventory.
The definition of "Offsite Eligible Inventory" in Section 1.1 of the Agreement
is hereby amended and restated in its entirety to read as follows:

                  "'Offsite Eligible Inventory' means, as to each Borrower,
         Inventory of such Borrower which would not be excluded from the
         definition of Eligible Inventory but for the fact that it is not
         located as a location specified in Schedule E-1; provided, that an item
         shall not be included in Offsite Eligible Inventory if it consists of
         goods in transit to or stored at storage facilities pursuant to a
         Terminal Agreement."

         Section 2.05. New Definition of Terminal Agreement. The definition of
"Terminal Agreement" is hereby added to Section 1.1 of the Agreement and made a
part thereof which shall read in its entirety as follows:

                  "'Terminal Agreement' means an agreement or contract between a
         Borrower and a third party providing for the storage and handling of
         Inventory of the Borrower at a site located in the continental United
         States or in Canada."

         Section 2.06. Amendment to Section 5.5. Section 5.5 of the Agreement is
hereby amended and restated in its entirety to read as follows:

                  "5.5 LOCATION OF INVENTORY. The Inventory is not stored with a
         bailee, warehouseman, or similar party and is located only at the
         locations identified on Schedule 5.5 (other than Inventory in transit
         between locations specified in Schedule 5.5 and Inventory in transit to
         or stored at storage facilities pursuant to a Terminal Agreement)."

         Section 2.07. Amendment to Section 6.9. Section 6.9 of the Agreement is
hereby amended and restated in its entirety to read as follows:

                  "6.9 LOCATION OF INVENTORY. Keep the Inventory (other than
         Inventory in transit between locations specified on Schedule 5.5 and
         Inventory in transit to or stored at storage facilities pursuant to a
         Terminal Agreement) only at the locations identified on Schedule 5.5;
         provided, however, that Borrowers may amend Schedule 5.5 so long as
         such amendment occurs by written notice to Agent not less than 30 days
         prior to the date on which the Inventory is moved to such new location,
         so long as such new location is within the continental United States or
         Canada, and so long as, at the time of such written notification, the
         applicable Borrower provides any UCC-1 financing statements, fixture
         filings, PPSA financing statements, or any other equivalent form of
         registration necessary to perfect and continue perfected the Agent's
         Liens on such assets and also provides to Agent a Collateral Access
         Agreement."

         Section 2.08. New Section 6.20. A new Section 6.20 is hereby added to
the Agreement and made a part thereof which reads as follows:

                  "6.20 TERMINAL AGREEMENTS. Upon entering into and executing a
         Terminal Agreement, the Borrower will immediately notify the Agent
         thereof specifying the third party party to such Terminal Agreement,
         the location of the site subject to the Terminal



FIFTH AMENDMENT TO LOAN AND SECURITY AGREEMENT - PAGE 2

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         Agreement, and the amount of Inventory proposed to be stored pursuant
         to the terms of the Terminal Agreement, and will accompany such notice
         with an executed copy of the Terminal Agreement. The Borrower will use
         its best efforts to obtain a terminal access agreement in form, scope
         and substance acceptable to Agent in connection with each such Terminal
         Agreement."

         Section 2.09. Amendment to Section 7.18. Section 7.18 of the Agreement
is hereby amended and restated in its entirety to read as follows:

                  "7.18 CHANGE IN LOCATION OF CHIEF EXECUTIVE OFFICE; INVENTORY
         WITH BAILEES. Relocate its chief executive office to a new location
         from the location specified in Schedule 5.7; provided, however, that
         Borrowers may amend Schedule 5.7 so long as such amendment occurs by
         written notice to Agent not less than 30 days prior to the date the
         chief executive office is to be relocated, so long as such location is
         within the continental United States or Canada, and so long as, at the
         time of such written notification, the applicable Borrower provides any
         UCC-1 financing statements or fixture filings or PPSA financing
         statements or any other equivalent form of registration necessary to
         perfect and continue perfected the Agent's Liens and also provides to
         Agent a Collateral Access Agreement with respect to such new location.
         The Inventory shall not at any time now or hereafter be stored with a
         bailee, warehouseman, or similar party without Agent's prior written
         consent (other than Inventory in transit to or stored at storage
         facilities pursuant to a Terminal Agreement)."

                                  ARTICLE III
                              CONDITIONS PRECEDENT

         Section 3.01. Conditions. The effectiveness of this Amendment is
subject to the satisfaction of the following conditions precedent, unless
specifically waived by Agent:

                  (a) Agent shall have received the following documents, each in
         form and substance satisfactory to Agent:

                           (i) This Amendment, duly executed by Borrowers,
                  together with the Consent and Ratification (the
                  "Ratification") hereto, duly executed by the Guarantors; and

                           (ii) Company General Certificates dated as of the
                  date of this Amendment, in form and substance satisfactory to
                  Agent, certified by the Secretary of the Borrowers and the
                  Guarantors certifying among other things, that the Borrowers'
                  and Guarantors Board of Directors have met and have adopted,
                  approved, consented to and ratified resolutions which
                  authorize the execution, delivery and performance by Borrowers
                  of this Amendment, and the Guarantors of the Ratification, and
                  each other document, instrument and agreement executed in
                  connection with or relating to the Agreement, this Amendment
                  or the Ratification (hereinafter individually referred to as a
                  "Loan Document" and collectively referred to as the "Loan
                  Documents");

                  (b) The representations and warranties contained herein, in
         the Agreement, as amended hereby, and/or in each other Loan Document
         shall be true and correct as of the date hereof, as if made on the date
         hereof;

                  (c) No Event of Default shall have occurred and be continuing
         and no Default shall exist, unless such Event of Default or Default has
         been specifically waived in writing by Agent; and


FIFTH AMENDMENT TO LOAN AND SECURITY AGREEMENT - PAGE 3

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                  (d) All corporate proceedings taken in connection with the
         transactions contemplated by this Amendment and all documents,
         instruments and other legal matters incident thereto, shall be
         satisfactory to Agent.

                                   ARTICLE IV
                  RATIFICATIONS, REPRESENTATIONS AND WARRANTIES

         Section 4.01. Ratifications. The terms and provisions set forth in this
Amendment shall modify and supersede all inconsistent terms and provisions set
forth in the Agreement and except as expressly modified and superseded by this
Amendment, the terms and provisions of the Agreement and the other Loan
Documents are ratified and confirmed and shall continue in full force and
effect. Borrowers and the Agent agree that the Agreement, as amended hereby, and
the other Loan Documents shall continue to be legal, valid, binding and
enforceable in accordance with their respective terms.

         Section 4.02. Representations and Warranties. Borrowers hereby
represent and warrant to Agent as follows:

                  (a) the execution, delivery and performance of this Amendment
         and any and all other Loan Documents executed and/or delivered in
         connection herewith have been authorized by all requisite corporate
         action on the part of Borrowers and do not and will not conflict with
         or violate any provision of any Applicable Law, the Articles of
         Incorporation/Organization or Bylaws/Operating Agreement of Borrower or
         any agreement, document, judgment, license, order or permit applicable
         to or binding upon any of the Borrowers or their respective Property;
         no consent, approval, authorization or order of and no notice to or
         filing with, any court or governmental authority or third person is
         required in connection with the execution, delivery or performance of
         this Amendment or to consummate the transactions contemplated hereby;

                  (b) the representations and warranties contained in the
         Agreement, as amended hereby, and any other Loan Document are true and
         correct on and as of the date hereof as though made on and as of the
         date hereof, except to the extent such representations and warranties
         relate to an earlier date;

                  (c) Borrowers are in full compliance with all covenants and
         agreements contained in the Agreement, as amended hereby, and the other
         Loan Documents; and

                  (d) Borrowers have not amended their respective Articles of
         Incorporation/Organization or Bylaws/Operating Agreement or other
         organizational documents since the date of the execution of the
         Agreement.

                                   ARTICLE V
                                  MISCELLANEOUS

         Section 5.01. Survival of Representations and Warranties. All
representations and warranties made in the Agreement or any other document or
documents relating thereto, including, without limitation, any Loan Document
furnished in connection with this Amendment, shall survive the execution and
delivery of this Amendment and the other Loan Documents, and no investigation by
Agent or any closing shall affect the representations and warranties or the
right of Agent to rely upon them.

         Section 5.02. Reference to Agreement. Each of the Loan Documents,
including the Agreement and any and all other agreements, documents or
instruments now or hereafter executed and delivered pursuant to the terms hereof
or pursuant to the terms of the Agreement, as amended hereby, are hereby amended
so that any reference in such Loan Documents to the Agreement shall mean a
reference to the Agreement, as amended hereby.


FIFTH AMENDMENT TO LOAN AND SECURITY AGREEMENT - PAGE 4

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         Section 5.03. Expenses of Agent. As provided in the Agreement, each
Borrower agrees to pay on demand all reasonable costs and expenses incurred by
Agent in connection with the preparation, negotiation and execution of this
Amendment and the other Loan Documents executed pursuant hereto and any and all
amendments, modifications, and supplements hereto, including, without
limitation, the reasonable costs and fees of Agent's legal counsel, and all
reasonable costs and expenses incurred by Agent in connection with the
enforcement or preservation of any rights under the Agreement, as amended
hereby, or any other Loan Document, including, without limitation, the
reasonable costs and fees of Agent's legal counsel.

         Section 5.04. RELEASE. EACH BORROWER HEREBY ACKNOWLEDGES THAT IT HAS NO
DEFENSE, COUNTERCLAIM, OFFSET, CROSS-COMPLAINT, CLAIM OR DEMAND OF ANY KIND OR
NATURE WHATSOEVER THAT CAN BE ASSERTED TO REDUCE OR ELIMINATE ALL OR ANY PART OF
ITS LIABILITY TO REPAY THE OBLIGATIONS OR TO SEEK AFFIRMATIVE RELIEF OR DAMAGES
OF ANY KIND OR NATURE FROM THE AGENT OR THE LENDERS. EACH BORROWER HEREBY
VOLUNTARILY AND KNOWINGLY RELEASES AND FOREVER DISCHARGES THE AGENT AND THE
LENDERS, THEIR PREDECESSORS, AGENTS, EMPLOYEES, SUCCESSORS AND ASSIGNS, FROM ALL
POSSIBLE CLAIMS, DEMANDS, ACTIONS, CAUSES OF ACTION, DAMAGES, COSTS, EXPENSES,
AND LIABILITIES WHATSOEVER, KNOWN OR UNKNOWN, ANTICIPATED OR UNANTICIPATED,
SUSPECTED OR UNSUSPECTED, FIXED, CONTINGENT, OR CONDITIONAL, AT LAW OR IN
EQUITY, ORIGINATING IN WHOLE OR IN PART ON OR BEFORE THE DATE THIS AMENDMENT IS
EXECUTED, WHICH THE BORROWER MAY NOW OR HEREAFTER HAVE AGAINST THE AGENT AND THE
LENDERS, THEIR PREDECESSORS, AGENTS, EMPLOYEES, SUCCESSORS AND ASSIGNS, IF ANY,
AND IRRESPECTIVE OF WHETHER ANY SUCH CLAIMS ARISE OUT OF CONTRACT, TORT,
VIOLATION OF LAW OR REGULATIONS, OR OTHERWISE, AND ARISING FROM ANY OF THE
OBLIGATIONS, INCLUDING, WITHOUT LIMITATION, ANY CONTRACTING FOR, CHARGING,
TAKING, RESERVING, COLLECTING OR RECEIVING INTEREST IN EXCESS OF THE HIGHEST
LAWFUL RATE APPLICABLE, THE EXERCISE OF ANY RIGHTS AND REMEDIES UNDER THE
AGREEMENT OR OTHER LOAN DOCUMENTS, AND NEGOTIATION FOR AND EXECUTION OF THIS
AMENDMENT.

         Section 5.05. Severability. Any provision of this Amendment held by a
court of competent jurisdiction to be invalid or unenforceable shall not impair
or invalidate the remainder of this Amendment and the effect thereof shall be
confined to the provision so held to be invalid or unenforceable.

         Section 5.06. APPLICABLE LAW. THIS AMENDMENT AND ALL OTHER LOAN
DOCUMENTS EXECUTED PURSUANT HERETO SHALL BE DEEMED TO HAVE BEEN MADE AND TO BE
PERFORMABLE IN DALLAS, TEXAS, AND SHALL BE GOVERNED BY AND CONSTRUED IN
ACCORDANCE WITH THE LAWS OF THE STATE OF TEXAS.

         Section 5.07. Successors and Assigns. This Amendment is binding upon
and shall inure to the benefit of Agent, the Lenders and the Borrowers and their
respective successors and assigns, except the Borrowers may not assign or
transfer any of their rights or obligations hereunder without the prior written
consent of Agent.

         Section 5.08. Counterparts. This Amendment may be executed in one or
more counterparts, each of which when so executed shall be deemed to be an
original, but all of which when taken together shall constitute one and the same
instrument.

         Section 5.09. Effect of Waiver. No consent or waiver, express or
implied, by Agent to or for any breach of or deviation from any covenant or
condition of the Agreement shall be deemed a consent or waiver to or of any
other breach of the same or any other covenant, condition or duty.


FIFTH AMENDMENT TO LOAN AND SECURITY AGREEMENT - PAGE 5

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         Section 5.10. Headings. The headings, captions, and arrangements used
in this Amendment are for convenience only and shall not affect the
interpretation of this Amendment.

         Section 5.11. FINAL AGREEMENT. THE AGREEMENT, AS AMENDED HEREBY AND THE
OTHER LOAN DOCUMENTS REPRESENT THE FINAL AGREEMENT BETWEEN THE PARTIES RELATED
TO THE SUBJECT MATTER HEREOF AND MAY NOT BE CONTRADICTED BY EVIDENCE OF PRIOR,
CONTEMPORANEOUS OR SUBSEQUENT ORAL AGREEMENTS OF THE PARTIES. THERE ARE NO
UNWRITTEN ORAL AGREEMENTS BETWEEN THE PARTIES.

         IN WITNESS WHEREOF, the Borrowers, Agent and the Lenders have caused
this Amendment to be executed on the date first written above by their duly
authorized officers.


                                      PCI CHEMICALS CANADA COMPANY
                                      a Nova Scotia unlimited liability company

                                      By:
                                         --------------------------------------
                                      Name:
                                           ------------------------------------
                                      Title:
                                            -----------------------------------

                                      PIONEER AMERICAS LLC
                                      a Delaware limited liability company

                                      By:
                                         --------------------------------------
                                      Name:
                                           ------------------------------------
                                      Title:
                                            -----------------------------------

                                      WELLS FARGO FOOTHILL, INC.,
                                      a California corporation (f/k/a Foothill
                                      Capital Corporation), as Agent and
                                      as a Lender

                                      By:
                                         --------------------------------------
                                      Name:
                                           ------------------------------------
                                      Title:
                                            -----------------------------------




FIFTH AMENDMENT TO LOAN AND SECURITY AGREEMENT - PAGE 6

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                            CONSENT AND RATIFICATION


         The undersigned, Pioneer Companies, Inc., Pioneer (East), Inc., Pioneer
Licensing, Inc., Imperial West Chemical Co., KNA California, Inc., Pioneer Water
Technologies, Inc., and KWT, Inc. (each a "Guarantor" and collectively the
"Guarantors") have executed that certain continuing general guaranty dated as of
December 31, 2001 (the "Guaranty"), in favor of WELLS FARGO FOOTHILL, INC., a
California corporation (f/k/a Foothill Capital Corporation), as the arranger and
administrative agent for the Lenders (as defined in the Guaranty). The
Guarantors hereby consent and agree to the terms of the Fifth Amendment to Loan
and Security Agreement dated as of July 1, 2003 (the "Amendment"), executed by
PCI CHEMICALS CANADA COMPANY, a Nova Scotia unlimited liability company, and
PIONEER AMERICAS LLC, a Delaware limited liability company (hereinafter each
individually is referred to as a "Borrower" and collectively as the
"Borrowers"), the Lenders and Agent, a copy of which is attached hereto, and the
undersigned agree that the Guaranty shall remain in full force and effect and
shall continue to be the legal, valid and binding obligation of the Guarantors
in enforceable against the Guarantors in accordance with its terms. Furthermore,
each Guarantor hereby agrees and acknowledges that (a) the Guaranty is a "Loan
Document" as such term is defined in the Amendment and as such term is defined
in the Agreement, (b) the Guaranty is not subject to any claims, defenses or
offsets, (c) nothing contained in this Amendment or any other Loan Document
shall adversely affect any right or remedy of Agent under the Guaranty, (d) the
execution and delivery of the Amendment shall in no way reduce, impair or
discharge any obligations of the undersigned as guarantors pursuant to the
Guaranty and shall not constitute a waiver by Agent of any of Agent's rights
against the undersigned, (e) by virtue hereof and by virtue of the Guaranty,
each Guarantor hereby guarantees to Agent the prompt and full payment and full
and faithful performance by the Borrowers of the entirety of the Obligations (as
defined in the Agreement) on the terms and conditions set forth in the Agreement
as amended by the Amendment and any time further modified or amended, (f) the
Guarantors' consent is not required to the effectiveness of the Amendment, and
(g) no consent by the Guarantors is required for the effectiveness of any future
amendment, modification, forbearance or other action with respect to the
Agreement or any present or future Loan Document.

                                      Pioneer Companies, Inc.


                                      By:
                                         --------------------------------------
                                      Name:   Kent R. Stephenson
                                      Title:  Vice President


                                      Pioneer (East), Inc.


                                      By:
                                         --------------------------------------
                                      Name:   Kent R. Stephenson
                                      Title:  President


CONSENT AND RATIFICATION OF FIFTH AMENDMENT TO LOAN AND SECURITY AGREEMENT -
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                                      Pioneer Licensing, Inc.


                                      By:
                                         --------------------------------------
                                      Name:   Kent R. Stephenson
                                      Title:  President

                                      Imperial West Chemical Co.


                                      By:
                                         --------------------------------------
                                      Name:   Kent R. Stephenson
                                      Title:  Vice President


                                      KNA California, Inc.


                                      By:
                                         --------------------------------------
                                      Name:   Kent R. Stephenson
                                      Title:  Vice President


                                      Pioneer Water Technologies, Inc.


                                      By:
                                         --------------------------------------
                                      Name:   Kent R. Stephenson
                                      Title:  Vice President


                                      KWT, Inc.


                                      By:
                                         --------------------------------------
                                      Name:   Kent R. Stephenson
                                      Title:  Vice President



CONSENT AND RATIFICATION OF FIFTH AMENDMENT TO LOAN AND SECURITY AGREEMENT -
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