Exhibit
31.1




CERTIFICATION PURSUANT TO


18
U.S.C. SECTION 1350,


AS
ADOPTED PURSUANT TO


SECTION
302 OF THE SARBANES-OXLEY ACT OF 2002





I, WALTER
C. JOHNSEN, certify that:




I have
reviewed this Quarterly Report on Form 10-Q of Acme United
Corporation;




Based on
my knowledge, this report does not contain any untrue statement of a material
fact or omit to state a material fact necessary to make the statements made, in
light of the circumstances under which such statements were made, not misleading
with respect to the period covered by this report;




Based on
my knowledge, the financial statements, and other financial information included
in this report, fairly present in all material respects the financial condition,
results of operations and cash flows of the registrant as of, and for, the
periods presented in this report;




The
registrant's other certifying officer(s) and I are responsible for establishing
and maintaining disclosure controls and procedures (as defined in Exchange Act
Rules 13a-15(e) and 15d-15(e)) and internal control over
financial reporting (as defined in Exchange Act Rules 13a-15(f) and 15d-15(f))for the registrant and have:




(a)
Designed such disclosure controls and procedures, or caused such disclosure
controls and procedures to be designed under our supervision, to ensure that
material information relating to the registrant, including its consolidated
subsidiaries, is made known to us by others within those entities, particularly
during the period in which this report is being prepared;




(b)Designed such
internal control over financial reporting, or caused such internal control over
financial reporting to be designed under our supervision, to provide reasonable
assurance regarding the reliability of financial reporting and the preparation
of financial statements for external purposes in accordance with generally
accepted accounting principles;




(c)
Evaluated the effectiveness of the registrant's disclosure controls and
procedures and presented in this report our conclusions about the effectiveness
of the disclosure controls and procedures, as of the end of the period covered
by this report based on such evaluation; and




(d)
Disclosed in this report any change in the registrant's internal control over
financial reporting that occurred during the registrant's most recent fiscal
quarter that has materially affected, or is reasonably likely to materially
affect, the registrant's internal control over financial reporting;
and




The
registrant's other certifying officer(s) and I have disclosed, based on our most
recent evaluation of internal control over financial reporting, to the
registrant's auditors and the audit committee of the registrant's board of
directors (or persons performing the equivalent functions):




(a) All
significant deficiencies and material weaknesses in the design or operation of
internal control over financial reporting which are reasonably likely to
adversely affect the registrant's ability to record, process, summarize and
report financial information; and




(b) Any
fraud, whether or not material, that involves management or other employees who
have a significant role in the registrant's internal control over financial
reporting.




By
                  /s/  Walter C.
      JohnsenWalter C.
      JohnsenChairman
      of the Board andChief
      Executive Officer




Dated:  May
10, 2010