<PAGE>


                     U.S. Securities and Exchange Commission
                             Washington, D.C. 20549
                                  Form 10-QSB

      [ X ] QUARTERLY REPORT UNDER SECTION 13 OR 15 (d) OF THE SECURITIES
                              EXCHANGE ACT OF 1934

                  For the quarterly period ended April 3, 1999
      [   ] TRANSITION REPORT UNDER SECTION 13 OR 15 (d) OF THE EXCHANGE ACT


                          Commission File Number 0-9478

                           SPECTRUM LABORATORIES, INC.
           Incorporated pursuant to the laws of the State of Delaware
                                                    -----------------

      Internal Revenue Service - Employer Identification Number 95-4718363

              23022 La Cadena Drive, Laguna Hills, California 92653
                     Address of principal executive offices

                    Issuer's Telephone Number (949) 581-3500

Check whether the issuer (1) filed all reports required to be filed by Section
13 or 15(d) of the Exchange Act during the past 12 months (or for such shorter
period that the registrant was required to file such reports), and (2) has been
subject to such filing requirements for the past 90 days.

                                Yes X    No
                                   ---     ---


  Number of shares of Common Stock outstanding as of April 30, 1999: 5,311,968


<PAGE>


Spectrum Laboratories, Inc.

<TABLE>
<CAPTION>

                                                                                      Page
                                                                                      ----
<S>                                                                                     <C>
Part I   - FINANCIAL INFORMATION

Item 1.    Financial Statements                                                
           Consolidated Balance Sheet as of April 3, 1999                                3
           Consolidated Statements of Income for the Three Months Ended         
              April 3, 1999 and April 4, 1998                                            4
           Consolidated Statements of Cash Flows for the Three Months Ended     
              April 3, 1999 and April 4, 1998                                            5
           Notes to Consolidated Statements                                              6
                                                                                
Item 2.    Management's Discussion and Analysis of Financial Condition                   7
                                                                                
                                                                                
Part II  - OTHER  INFORMATION                                                   
                                                                                
Item 1.    Legal Proceedings                                                             9
Item 2.    Changes in Securities                                                         9
Item 3.    Defaults Upon Senior Securities                                               9
Item 4.    Submission of Matters to a Vote of Security Holders                           9
Item 5.    Other Information                                                             9
Item 6.    Exhibits and Reports on Form 8-K                                              9
Signature                                                                               10
                                                                                
                                                                              
</TABLE>


                                       2
<PAGE>


Part I.  FINANCIAL INFORMATION

Item 1.  Financial Statements

<TABLE>

                                                   SPECTRUM LABORATORIES, INC.
                                                   CONSOLIDATED BALANCE SHEET
                                                       AS OF APRIL 3, 1999
                                            (DOLLARS IN THOUSANDS, EXCEPT PAR VALUE)
                                                           (UNAUDITED)
<CAPTION>

<S>                                                                                             <C>           
      ASSETS
      CURRENT ASSETS
           Cash and cash equivalents                                                            $        1,043
           Accounts receivable                                                                           1,554
           Inventories                                                                                   1,577
           Prepaid expenses                                                                                203
           Deferred taxes                                                                                  377
                                                                                                ---------------

           Total current assets                                                                          4,754

      Equipment and leasehold improvements                                                               2,154
      Goodwill                                                                                           2,658
      Other assets                                                                                         464
                                                                                                ---------------

           TOTAL ASSETS                                                                         $       10,030
                                                                                                ===============

      LIABILITIES AND SHAREHOLDERS' EQUITY
      CURRENT LIABILITIES
           Current portion of long-term debt                                                    $        1,021
           Accounts payable                                                                                722
           Accrued expenses and other current liabilities                                                1,001
                                                                                                ---------------

           Total current                                                                                           
           liabilities                                                                                   2,744     

      LONG-TERM DEBT, less current portion                                                               1,380

      MINORITY INTEREST                                                                                  2,000

      SHAREHOLDERS' EQUITY
           Common stock, par value $.01:  25,000,000 shares authorized;
              5,311,968 issued and outstanding                                                              53
           Preferred stock, par value $.01: 10,000,000 shares authorized;                                                  
              none issued or outstanding                                                                                   
           Additional paid in capital                                                                    8,026
           Accumulated deficit                                                                          (4,173)
                                                                                                ---------------

      TOTAL SHAREHOLDERS' EQUITY                                                                         3,906
                                                                                                ---------------

      TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY                                                $       10,030
                                                                                                ===============
</TABLE>


                                       3
<PAGE>

<TABLE>
                                 SPECTRUM LABORATORIES, INC.
                              CONSOLIDATED STATEMENTS OF INCOME
                      THREE MONTHS ENDED APRIL 3, 1999 AND APRIL 4, 1998
                         (IN THOUSANDS, EXCEPT FOR PER SHARE AMOUNTS)
                                         (UNAUDITED)

<CAPTION>

                                                                                     1999           1998
                                                                                   ----------    ----------

<S>                                                                                <C>           <C>     
NET SALES                                                                          $   3,297     $   3,200

COSTS AND EXPENSES
  Cost of sales                                                                        1,671         1,639
  Selling                                                                                340           461
  General and administrative                                                             731           789
  Research and development                                                               163           150
  Other expense, primarily interest                                                       48            79
                                                                                   ----------    ----------
                                                                                       2,953         3,118
  Total costs and expenses

Income before provision for income taxes                                                 344            82

Provision for income taxes                                                               141             9
                                                                                   ----------    ----------

Net income                                                                         $     203     $      73
                                                                                   ==========    ==========



Earnings per share
    Basic                                                                          $     .04     $     .02
                                                                                   ==========    ==========
    Diluted                                                                        $     .04     $     .02
                                                                                   ==========    ==========

Weighted average shares outstanding
    Basic                                                                              5,312         4,815
                                                                                   ==========    ==========
    Diluted                                                                            5,459         4,821
                                                                                   ==========    ==========
</TABLE>


                                       4
<PAGE>

<TABLE>
                                              SPECTRUM LABORATORIES, INC.
                                         CONSOLIDATED STATEMENTS OF CASH FLOWS
                                  THREE MONTHS ENDED APRIL 3, 1999 AND APRIL 4, 1998
                                                    (IN THOUSANDS)
                                                      (UNAUDITED)
<CAPTION>
                                                                                       1999                   1998
                                                                                 ----------------      ----------------

<S>                                                                              <C>                   <C>            
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income                                                                       $           203       $            73
Adjustments to reconcile net income to net cash provided by
    operating activities:
Depreciation and amortization                                                                175                   159
Minority interest in loss of subsidiary                                                                             (5)
Change in assets and liabilities:
(Increase) decrease in accounts receivables                                                  (35)                    5
Decrease in inventories                                                                      119                     1
(Increase) decrease in prepaid expenses                                                      (80)                   40
Increase in other assets                                                                     (28)                   (7)
Decrease in accounts payable                                                                 (45)                  (91)
Increase in accrued expenses and other current liabilities                                   220                    58
Other                                                                                         10
                                                                                 ----------------      ----------------

Net cash provided by operating activities                                                    539                   233
                                                                                 ----------------      ----------------

CASH FLOWS FROM INVESTING ACTIVITIES:
Acquisitions of equipment and leasehold improvements                                         (75)                 (113)
Increase in investments                                                                                           (483)
Advances to principal shareholder                                                            (39)                  (24)
Proceeds from the sale of equipment                                                           29
                                                                                 ----------------      ----------------

Net cash used in investing activities                                                        (85)                 (620)
                                                                                 -----------------     ----------------

CASH FLOWS FROM FINANCING ACTIVITIES:
Principal payments on debt                                                                  (266)                 (314)
Proceeds from issuance of debt                                                                                     275
                                                                                 ----------------      ----------------

Net cash used in financing activities                                                       (266)                  (39)
                                                                                 -----------------     ----------------


NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS                                         188                  (426)

CASH AND CASH EQUIVALENTS, beginning of period                                               855                 1,135
                                                                                 ----------------      ----------------

CASH AND CASH EQUIVALENTS, end of period                                         $         1,043       $           709
                                                                                 ================      ================
</TABLE>


                                       5
<PAGE>


NOTES TO CONSOLIDATED STATEMENTS

Note 1 - Basis of Presentation

The accompanying unaudited financial statements consolidate the accounts of
Spectrum Laboratories, Inc. and its subsidiaries, SLI Acquisition Corp.,
Spectrum Europe B.V. and Spectrum Chromatography (collectively, the Company).
All significant intercompany transactions have been eliminated in consolidation.
In the opinion of management, the accompanying unaudited interim consolidated
financial statements contain all adjustments (consisting only of normal
recurring accruals) necessary to present fairly the financial position of the
Company as of April 3, 1999 and the results of its operations and its cash flows
for the three months ended April 3, 1999 and April 4, 1998. Certain information
and footnote disclosures normally included in the financial statements have been
condensed or omitted pursuant to rules and regulations of the Securities and
Exchange Commission, although the Company believes that the disclosures in the
unaudited interim financial statements are adequate to make the information
presented not misleading.

Note 2 - Reorganization

On September 30, 1998, Spectrum Medical Industries, Inc. (SMI), which formerly
owned 79.9% of Spectrum Laboratories, Inc. merged with Spectrum Laboratories,
Inc. (SLI). The merger was a combination of two companies under common control
and has been accounted for in a manner similar to a pooling of interests. The
consolidated financial statements of Spectrum Laboratories, Inc. for the period
ended April 4, 1998 are those of Spectrum Medical Industries, Inc. and
subsidiaries and have been restated to reflect the effects of the merger with
Spectrum Laboratories, Inc. In connection with this reorganization, SMI
distributed its 79.9% ownership in SLI, 1,013,543 shares, to the stockholders of
SMI and the Company effected a one-for-ten reverse stock split and
reincorporated in Delaware. This reverse stock split has been accounted for as
if it occurred as of the beginning of the earliest period presented in these
consolidated financial statements. Accordingly, stock options and corresponding
exercise prices have been adjusted to reflect the reverse split.

Note 3 - Inventories

Inventories are stated at the lower of cost, determined using the first-in,
first-out method, or net realizable value and are composed of the following (in
thousands):

                   Raw materials                    $     939
                   Work in progress                        33
                   Finished goods                         605
                                                    ----------

                                                    $   1,577
                                                    ==========

Note 4 - Earnings per Share

Basic earnings per share is computed by dividing the net income attributable to
the common stockholders by the weighted average number of common shares
outstanding during the period. There is no adjustment in the net income
attributable to common stockholders. Diluted earnings per share reflects the
potential dilution that could occur from common shares issuable through stock
options (146,592 and 5,289 shares in the fiscal periods 1999 and 1998,
respectively).

Note 5 - Income Taxes

At January 2, 1999, the Company had net operating loss carryforwards for federal
income tax purposes available to offset future taxable income. Certain of these
loss carryforwards are available to offset separate taxable income of one of the
companies and are limited to approximately $298,000 of that entity's income
annually. Any unused net operating loss is carried forward. As a result of the
limitation, it is possible that more than $5,000,000 of the entity's net
operating loss may expire without utilization.

The income tax provision for 1998, as a percentage of income before the tax
provision, is lower than expected primarily because SMI, prior to its merger
into the Company, was an S corporation and, hence, paid no federal income taxes
and had a low state income tax rate. 


                                       6
<PAGE>


Note 6 - Product Group Information

The Company's product groups are based on specific product characteristics and
are grouped into laboratory products and operating room disposable products.
Laboratory products consist primarily of: (1) membranes used to concentrate,
separate and purify dissolved or suspended molecules that are sold primarily to
laboratories and (2) hollow fiber membrane devices that allow components
retained by a membrane to be concentrated including filters utilized for micro
and ultrafiltration separations that are sold to biotech and pharmaceutical
companies. Operating room disposable products consist of sterile plastic
surgical drapes and cloth bandages that are sold primarily to hospitals.

Revenue by product group is as follows (in thousands):

                                                   1999             1998 
                                                ---------        ---------

Laboratory products                             $  2,874         $  2,769
Operating room disposable products                   423              431
                                                ---------        ---------

                                                $  3,297         $  3,200
                                                =========        =========


Item 2.  Management's Discussion and Analysis of Financial Condition and Results
        of Operations

The following discussion should be read in conjunction with the Consolidated
Financial Statements and Notes thereto contained elsewhere within this Report on
Form 10-QSB. Except for the historical information contained herein, the
following discussion may contain forward-looking statements that involve risks
and uncertainties. The actual future results of the Company could differ
materially from those discussed here. Factors that could cause or contribute to
such differences include, but are not limited to, those discussed in this report
and those factors discussed in the Company's Form 10-KSB for the year ended
January 2, 1999, as filed with the Securities and Exchange Commission and, from
time to time, in the Company's other reports on file with the Commission.

In September 1998, Spectrum Medical Industries, Inc. (SMI), which formerly owned
approximately 79.9% of the Company, was merged into the Company. As a result,
the operating results of all periods presented include the operations of SMI and
those of Chromatography, which was formerly a subsidiary of SMI and is now a
subsidiary of the Company.

Results of Operations

Selling and general and administrative expenses for the first quarter of fiscal
1999 decreased 14% from the first quarter of fiscal 1998. The decrease was
primarily due to cost reduction measures implemented during the third quarter of
1998.

The income tax provision for 1998, as a percentage of income before the tax
provision, is lower than expected primarily because SMI, prior to its merger
into the Company, was an S corporation and, hence, paid no federal income taxes
and had a low state income tax rate.

Liquidity and Capital Resources

In the first quarter of 1999, $539,000 of cash was generated from operating
activities. Net income before the non-cash expenses of depreciation and
amortization was the primary source of the positive cash flow. The cash flow was
offset, to a large extent, by the purchase of equipment and payments on debt.

Significant non-operating outflows of cash during the remainder of fiscal 1999
may result from the relocations of the Company's California operations, from
three locations to one, and a bank loan of approximately $300,000 that becomes
due on June 1, 1999, although this due date may be extended.

Management of the Company believes that cash on hand and cash expected to be
generated from operations will be sufficient to meet cash requirements for the
remainder of fiscal 1999.


                                       7
<PAGE>


Year 2000 Matters

The Year 2000 issue is the result of computer programs being written using two
digits rather than four to define the applicable year. Any of the Company's
hardware or computer programs that have time-sensitive software may recognize a
date using "00" as the year 1900 rather than the Year 2000. The Company is in
the process of converting from existing hardware and accounting software to
hardware and software programs that are Year 2000 compliant.

The Company has had formal communications with substantially all of its
significant suppliers and large customers to determine the extent to which the
Company's interface systems are vulnerable to those third parties' failure to
remediate their own Year 2000 issue. Although the results of these
communications did not indicate that any problems were expected, there can be no
guarantee that the systems of other companies on which the Company's operations
rely will be timely converted and would not have an adverse effect on the
Company's ability to obtain products and services from vendors or collect
receivables from customers.

The Company will utilize both internal and external resources to reprogram, or
replace, and test the software and equipment for Year 2000 modifications and
anticipates completing these modifications no later than September 1999. The
total cost of the Year 2000 project is estimated at $50,000, is being funded
through operating cash flows, and the costs are being expensed as incurred.
Approximately $16,000 had been expended as of April 3, 1999.

The costs of the project and the date on which the Company believes it will
complete the Year 2000 modifications are based on management's best estimates,
which were derived from assumptions of future events, including the continued
availability of certain resources, third-party modification plans and other
factors. However, there can be no guarantee that these estimates will be
achieved and actual results could differ materially from those anticipated.
Specific factors that might cause such material differences include, but are not
limited to, the availability and cost of personnel trained in this area, the
ability to locate and correct all relevant computer codes and hardware, and
similar uncertainties.

Management is of the opinion that the year 2000 issue will not pose significant
operational problems for the Company. However, should these conversions by the
Company and by its significant suppliers and customers not be successfully
completed on a timely basis, a potential worst-case effect on the Company could
be a significant disruption of operations, including, among other things, an
inability to obtain materials from vendors, make timely shipments to customers,
a temporary inability to process transactions, send invoices to its customers,
or engage in similar normal business activities. The Company does not have a
contingency back-up plan in case such conversions are not completed on a timely
basis.


                                       8
<PAGE>


Part II.  OTHER INFORMATION

Item 1.  Legal Proceedings
         None

Item 2.  Change in Securities
         None

Item 3.  Defaults upon Senior Securities
         Not Applicable

Item 4.  Submission of Matters to a Vote of Security Holders
         None

Item 5.  Other Information
         None

Item 6.  Exhibits and reports on Form 8-K

         (a)  Exhibits

              Exhibit 10.20 - Sublease agreement dated January 19, 1999 between
              Millipore Corporation and Spectrum Laboratories, Inc.

         (b)  Reports on Form 8-K filed during the quarter ended April 3, 1999.

              Report, dated September 30, 1998, regarding the merger of
              Spectrum Medical Industries, Inc. into Spectrum Laboratories,
              Inc. Financial statements submitted with this Report were as
              follows:

              A.   Financial Statements of Spectrum Medical Industries, Inc.

                   1.   Audited Consolidated Financial Statements of Spectrum
                        Medical Industries, Inc. and Subsidiaries as of January
                        3, 1998 and December 31, 1996 and for each year then
                        ended

                   2.   Unaudited Consolidated Balance Sheet as of October 3,
                        1998

                   3.   Unaudited Consolidated Statements of Operations for the
                        nine months ended October 3, 1998 and September 30,
                        1997

                   4.   Unaudited Consolidated Statement of Shareholders'
                        Equity for the period January 4, 1998 through October
                        3, 1998

                   5.   Unaudited Consolidated Statements of Cash Flows for the
                        nine months ended October 3, 1998 and September 30,
                        1997

              B.   Pro Forma Financial Information of Spectrum Medical
                   Industries, Inc. and Spectrum Laboratories, Inc.

                   1.   Unaudited Pro Forma Consolidated Balance Sheets as of
                        October 3, 1998

                   2.   Unaudited Pro Forma Consolidated Statements of
                        Operations for the years ended January 3, 1998 and
                        December 31, 1996 and nine months ended October 3, 1998
                        and September 30, 1997


                                       9
<PAGE>


SIGNATURES

In accordance with the requirements of the Exchange Act, the registrant caused
this report to be signed on its behalf by the undersigned, thereunto duly
authorized.

SPECTRUM LABORATORIES, INC.
(Registrant)




/s/  F. Jesus Martinez
----------------------
Signature

F. Jesus Martinez
President

Date:  May 17, 1999




 /s/  Larry D. Womack
-----------------------
Signature

Larry D. Womack
Vice President Finance

Date:  May 17, 1999


                                       10