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                                                                     Exhibit 5.3

January 8, 1998

PCI Chemicals Canada Inc.
c/o Pioneer Americas Acquisition Corp.
4300 NationsBank Center
700 Louisiana Street
Houston, Texas 77002

Re: Registration Statement on Form S-4
    (File No. 333-41221)

Ladies and Gentlemen:

We are counsel to PCI Chemicals Canada Inc., a New Brunswick, Canada
corporation (the "Company" and, together with Pioneer Americas Acquisition
Corp., a Delaware corporation ("PAAC") and the other subsidiaries of PAAC, the
"Issuers"), and have acted as such in connection with various legal matters
relating to the filing of a Registration Statement on Form S-4 (File No.
333-41221) (the "Registration Statement") under the Securities Act of 1933, as
amended (the "Securities Act"), covering up to $175,000,000 in aggregate
principal amount of 9-1/4% Series B Senior Secured Notes due 2007 (the
"Exchange Notes") offered in exchange for up to $175,000,000 in aggregate
principal amount of outstanding 9-1/4% Series A Senior Secured Notes due 2007
originally issued and sold in reliance upon an exemption from registration
under the Securities Act (the "Original Notes"). The Original Notes were issued
under, and the Exchange Notes are to be issued under, an Indenture, dated as of
October 30, 1997 (the "Indenture"), by and among the Issuers and the United
States Trust Company of New York, as trustee. The exchange will be made
pursuant to an exchange offer (the "Exchange Offer") contemplated by the
Registration Statement.

In so acting, we have examined copies of such records of the Issuers and such
other certificates and documents as we have deemed relevant and necessary for
the opinions hereinafter set forth. In such examination, we have assumed the
genuineness of all signatures, the authenticity of all documents submitted to
us as originals and the conformity to authentic originals of all documents
submitted to us as certified or reproduced copies. We have also assumed the
legal capacity of all persons executing such documents and the truth and
correctness of any representations or warranties therein contained.  
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PCI Chemicals Canada Inc.
January 8, 1998
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We have relied upon certificates of officers of the Issuers and of public
officials with respect to the accuracy of all factual matters contained therein,
all of the contents of which we have assumed continue to be accurate as of the
date of this opinion letter.

Based upon the foregoing, we are of the opinion that:

1.       The Company is duly formed and validly existing under the laws of the
         province of New Brunswick, Canada.

2.       The Indenture has been duly authorized, executed and delivered by the
         Company.

3.       The Exchange Notes have been duly authorized by the Company.

This opinion is limited to the laws of the Province of New Brunswick, Canada of
the type typically applicable to transactions contemplated by the Exchange
Offer, and we do not express any opinion with respect to the laws of any other
country, state or jurisdiction.

This opinion letter is limited to the matters stated herein and no opinion is
implied or may be inferred beyond the matters expressly stated. This opinion
letter may be relied upon by Willkie Farr & Gallagher in connection with the
Exchange Offer.

This letter speaks only as of the date hereof and is limited to present
statutes, regulations and administrative and judicial interpretations. We
undertake no responsibility to update or supplement this letter after the date
hereof.

We consent to being named in the Registration Statement and related Prospectus
as counsel who are passing upon the legality of the Exchange Notes and the
Guarantees and to the reference to our name under the caption "Legal Matters"
in such Prospectus. We also consent to your filing copies of this opinion as an
exhibit to the Registration Statement or any amendment thereto.

Very truly yours,

/s/ Stewart McKelvey Stirling Scales