<TABLE> <S> <C>

<PAGE>
<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE
CONSOLIDATED BALANCE SHEET AS OF SEPTEMBER 30, 1999 AND DECEMBER 31, 1998 AND
THE STATEMENT OF OPERATIONS FOR THE THREE AND NINE MONTHS ENDED SEPTEMBER 30,
1999 AND SEPTEMBER 30, 1998 AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO
SUCH FINANCIAL STATEMENTS.
</LEGEND>
<CIK> 0000884269
<NAME> ALPHA PRO TECH LTD
<MULTIPLIER> 1,000

<S>                             <C>                     <C>
<PERIOD-TYPE>                   3-MOS                   9-MOS
<FISCAL-YEAR-END>                          DEC-31-1999             DEC-31-1999
<PERIOD-START>                             JUL-01-1999             JAN-01-1999
<PERIOD-END>                               SEP-30-1999             SEP-30-1999
<CASH>                                             630                     630
<SECURITIES>                                         0                       0
<RECEIVABLES>                                     3874                    3874
<ALLOWANCES>                                        48                      48
<INVENTORY>                                       3173                    3173
<CURRENT-ASSETS>                                  7844                    7844
<PP&E>                                            3956                    3956
<DEPRECIATION>                                    1738                    1738
<TOTAL-ASSETS>                                   10667                   10667
<CURRENT-LIABILITIES>                             3625                    3625
<BONDS>                                              0                       0
<PREFERRED-MANDATORY>                                0                       0
<PREFERRED>                                          0                       0
<COMMON>                                           241                     241
<OTHER-SE>                                       24342                   24342
<TOTAL-LIABILITY-AND-EQUITY>                     10667                   10667
<SALES>                                           5176                   14888
<TOTAL-REVENUES>                                  5176                   14888
<CGS>                                             3247                    9006
<TOTAL-COSTS>                                     1647                    4969
<OTHER-EXPENSES>                                     0                       0
<LOSS-PROVISION>                                     0                       0
<INTEREST-EXPENSE>                                  41                     121
<INCOME-PRETAX>                                    241                     792
<INCOME-TAX>                                         0                       0
<INCOME-CONTINUING>                                241                     792
<DISCONTINUED>                                       0                       0
<EXTRAORDINARY>                                      0                       0
<CHANGES>                                            0                       0
<NET-INCOME>                                       241                     792
<EPS-BASIC>                                       0.01                    0.03
<EPS-DILUTED>                                     0.01                    0.03


</TABLE>