LONG-TERM INCENTIVE PLAN

Exhibit 10.4

ZEP INC.

LONG-TERM INCENTIVE PLAN

(Effective as of October 31, 2007)

The purposes of the Zep Inc. Long-Term Incentive Plan (the “Plan”) are to provide additional incentives to those officers, key executives and directors of Zep Inc. (the “Company”) and key employees of its Subsidiaries (as hereinafter defined) whose substantial contributions are essential to the continued growth and profitability of the Company’s businesses, to strengthen their commitment to the Company and its Subsidiaries, to further motivate those officers, other executives and directors to perform their assigned responsibilities diligently and skillfully, and to attract and retain competent and dedicated individuals whose efforts will result in the long term growth and profitability of the Company and, over time, appreciation in the market value of its stock. To accomplish these purposes, the Plan provides that the Company may grant to Eligible Employees, Incentive Stock Options, Nonqualified Stock Options, Stock Appreciation Rights, Restricted Stock, Restricted Stock Units, Performance Units and Performance Shares (as each term is hereinafter defined) and to eligible Directors, Nonqualified Stock Options, Stock Appreciation Rights, Restricted Stock and Restricted Stock Units.

In connection with the spin-off (the “Spin-off”) of the Company by Acuity Brands, Inc. (“Acuity Brands”), effective October 31, 2007, Options and Awards will be granted under this Plan as Conversion Awards to former employees of Acuity Brands and its Subsidiaries who remain or become employees of the Company and its Subsidiaries.

(a) “Acuity Brands” means Acuity Brands, Inc., a Delaware corporation, or any successor corporation.

(b) “Acuity Brands Conversion Awards” means Options or Awards that are issued in substitution of, or in connection with, stock options or grants of restricted stock or restricted stock units that were granted under the Acuity Brands Long-Term Incentive Plan to employees of Acuity Brands and its Subsidiaries who became employees of the Company and its Subsidiaries (or who were otherwise considered Transferred Individuals under the Employee Benefits Agreement) as of the date of the Spin-off of the Company to the stockholders of Acuity Brands. As provided in Sections 6(j) and 7(c), the Acuity Brands Conversion Awards shall have the same material terms and conditions under the Plan as such awards had under the Acuity Brands Long-Term Incentive Plan.

(c) “Acuity Brands Long-Term Incentive Plan” means the long-term incentive plan sponsored by Acuity Brands, known as the Acuity Brands, Inc. Long-Term Incentive Plan.

(d) “Adjusted Fair Market Value” means in the event of a Change in Control, the

greater of (i) the highest price per share paid to holders of the Shares in any transaction (or series of transactions) constituting or resulting in a Change in Control or (ii) the highest Fair Market Value of a Share during the ninety (90) day period ending on the date of a Change in Control.

(e) “Agreement” means the written agreement between the Company and an Optionee or Grantee evidencing the grant of an Option or Award and setting forth the terms and conditions thereof. The Committee may, but need not, require that the Participant execute a copy of the Agreement before the Agreement becomes effective.

(f) “Award” means a grant of a Stock Appreciation Right, Restricted Stock, Restricted Stock Units, Performance Awards, or any or all of them.

(g) “Board” means the Board of Directors of the Company.

(h) “Business Unit” means any of the operating units of the Company, or its Subsidiaries, designated as a Business Unit by the Committee.

(i) “Change in Capitalization” means any increase or reduction in the number of Shares, or any change (including, but not limited to, a change in value) or exchange of Shares for a different number or kind of shares or other securities of the Company, by reason of a reclassification, recapitalization, merger, consolidation, reorganization, spin-off, split-up, issuance of warrants or rights or debentures, stock dividend, stock split or reverse stock split, extraordinary cash dividend, property dividend, combination or exchange of shares, repurchase of shares, public offering, private placement, change in corporate structure or otherwise.

(j) “Change in Control” means any of the following events:

(i) The acquisition (other than from the Company) by any “Person” (as the term is used for purposes of Sections 13(d) or 14(d) of the Exchange Act) of beneficial ownership (within the meaning of Rule 13d-3 promulgated under the Exchange Act) of twenty percent (20%) or more of the combined voting power of the Company’s then outstanding voting securities; or

(ii) The individuals who, as of October 31, 2007, are members of the Board (the “Incumbent Board”), cease for any reason to constitute at least two-thirds of the Board; provided, however, that if the election, or nomination for election by the Company’s stockholders, of any new director was approved by a vote of at least two-thirds of the Incumbent Board, such new director shall, for purposes of this Agreement, be considered as a member of the Incumbent Board; or

(iii) Consummation of a merger or consolidation involving the Company if the stockholders of the Company, immediately before such merger or consolidation do not, as a result of such merger or consolidation, own, directly or indirectly, more than sixty percent (60%) of the combined voting power of the then outstanding voting securities of the corporation resulting from such merger or consolidation in substantially the same proportion as their ownership of the combined voting power of the voting securities of the Company outstanding immediately before such merger or consolidation; or

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(iv) Consummation of a complete liquidation or dissolution of the Company or an agreement for the sale or other disposition of all or substantially all of the assets of the Company.

Notwithstanding the foregoing, a Change in Control shall not be deemed to occur pursuant to Section 2(j)(i), solely because twenty percent (20%) or more of the combined voting power of the Company’s then outstanding securities is acquired by (i) a trustee or other fiduciary holding securities, under one or more employee benefit plans maintained by the Company or any of its subsidiaries or (ii) any corporation which, immediately prior to such acquisition, is owned directly or indirectly by the stockholders of the Company in the same proportion as their ownership of stock in the Company immediately prior to such acquisition.

(k) “Code” means the Internal Revenue Code of 1986, as amended.

(l) “Committee” means a committee consisting of two or more non-employee members of the Board who are appointed by the Board to administer the Plan and to perform the functions set forth herein. The Board or the Committee may designate a subcommittee of members of the Committee to act on certain matters where such designation is necessary or desirable.

(m) “Company” means Zep Inc., a Delaware corporation, or any successor corporation.

(n) “Director” means any individual who is a member of the Board of Directors of the Company; provided, however, that any Director who is employed by the Company or any Employer shall not be considered a Director, but instead shall be considered an employee for purposes of the Plan.

(o) “Disability” means a physical or mental incapacity which impairs the Optionee’s or Grantee’s ability to substantially perform his duties for a period of one hundred eighty (180) consecutive days. The determination of Disability shall be made by the Committee based upon the information provided to it.

(p) “Eligible Employee” means any officer or other employee of the Company or a Subsidiary designated by the Committee as eligible to receive Options or Awards, subject to the conditions set forth herein.

(q) “Employee Benefits Agreement” means the Employee Benefits Agreement between Acuity Brands and the Company, dated as of October 31, 2007, which provides for the treatment of the employee plans in connection with the Spin-off of the Company from Acuity Brands.

(r) “Employment Agreement” means with respect to a Participant who is an employee, the written agreement between the Company or a Subsidiary and the employee providing for the terms of such employee’s employment with the Company or a Subsidiary, as it may be amended from time to time.

(s) “Exchange Act” means the Securities Exchange Act of 1934, as amended.

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(t) “Fair Market Value” means the fair market value of the Shares as determined in good faith by the Committee; provided, however, that (A) if the Shares are admitted to trading on a national securities exchange, Fair Market Value on any date shall be the last sale price reported for the Shares on such exchange on such date or, if no sale was reported on such date, on the last date preceding such date on which a sale was reported, and (B) if the Shares are not listed on any securities exchange, but nevertheless are publicly traded and reported (through the OTC Bulletin Board or otherwise), Fair Market Value on such date shall be the closing sales price on such date (or, if there are no sales on such date, on the next preceding day).

For purposes of subsection (A), if the Shares are traded on more than one securities exchange then the largest U.S. exchange on which the Shares are traded shall be referenced to determine Fair Market Value.

(u) “Grantee” means a person to whom an Award has been granted under the Plan.

(v) “Incentive Stock Option” means an Option within the meaning of Section 422 of the Code.

(w) “Named Executive Officer” means an Eligible Employee who as of the date of grant, vesting and/or payout of an Award or Option is deemed by the Committee to be a “covered employee” as defined in Code Section 162(m) and the regulations and rulings thereunder.

(x) “Nonqualified Stock Option” means an Option which is not an Incentive Stock Option.

(y) “Option” means an Incentive Stock Option, a Nonqualified Stock Option, or either or both of them.

(z) “Optionee” means a person to whom an Option has been granted under the Plan.

(aa) “Participant” means an Eligible Employee or Director who has an outstanding Award or Option under the Plan.

(bb) “Performance Awards” means Performance Units, Performance Shares or either or both of them.

(cc) “Performance Cycle” means the time period specified by the Committee at the time a Performance Award is granted during which the performance of the Company, a Subsidiary or a Business Unit will be measured.

(dd) “Performance Shares” means Restricted Stock granted under Section 8 of the Plan.

(ee) “Performance Unit” means Performance Units granted under Section 8 of the Plan.

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(ff) “Restricted Stock” means Shares issued or transferred to a Participant which are subject to restrictions. Restricted Stock may be awarded subject to restrictions which lapse over time without regard to the performance of the Company, a Subsidiary or a Business Unit, pursuant to Section 7 hereof, or may be awarded as Performance Shares pursuant to Section 8 hereof.

(gg) “Restricted Stock Units (or RSUs)” means a right granted under Section 7 of the Plan to receive a number of Shares, or a cash payment for each such Share equal to the Fair Market Value of a Share, on a specified date.

(hh) “Retirement” means the voluntary termination of employment by the Grantee or Optionee at any time on or after the Grantee or Optionee attains age 65.

(ii) “Shares” means the common stock, par value $.01 per share, of the Company (including any new, additional or different stock or securities resulting from a Change in Capitalization).

(jj) “Stock Appreciation Right” (or “SAR”) means a right granted under Section 9 of the Plan to receive for each Share subject to an Award a cash payment or Shares equal to the excess, if any, of (i) the Fair Market Value of a Share on the exercise date, over (ii) the exercise price of the SAR.

(kk) “Subsidiary” means any corporation in an unbroken chain of corporations, beginning with the Company (or Acuity Brands, in the case of Acuity Brands Conversion Awards), if each of the corporations other than the last corporation in the unbroken chain owns stock possessing 50% or more of the total combined voting power of all classes of stock in one of the other corporations in such chain. The term “Subsidiary” shall also include a partnership in which the Company or a Subsidiary owns 50% or more of the profits interest or capital interest in the partnership.

(ll) “Successor Corporation” means a corporation, or a parent or subsidiary thereof within the meaning of Section 424(a) of the Code, which issues or assumes an Option in a transaction to which Section 424(a) of the Code applies.

(mm) “Ten-Percent Stockholder” means an Eligible Employee who, at the time an Incentive Stock Option is to be granted to him, owns (within the meaning of Section 422(b)(6) of the Code) stock possessing more than ten percent (10%) of the total combined voting power of all classes of stock of the Company.

(nn) “Termination for Cause” means the Optionee or Grantee has terminated employment and has been found by the Committee to be guilty of theft, embezzlement, fraud or misappropriation of the Company’s property or any action which, if the individual were an officer of the Company, would constitute a breach of fiduciary duty, provided that if an Optionee or Grantee has an Employment Agreement, “Cause” shall mean Cause as defined in such Agreement.

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(a) The Plan shall be administered by the Committee, which shall hold such meetings as may be necessary for the proper administration of the Plan. No member of the Committee shall be personally liable for any action, determination or interpretation made in good faith with respect to the Plan, or any Agreements, Options or Awards under the Plan, and all members of the Committee shall be fully indemnified by the Company with respect to any such action, determination or interpretation.

(b) Subject to the express terms and conditions set forth herein, the Committee shall have the power from time to time:

(i) to determine those Eligible Employees and Directors to whom Options shall be granted under the Plan and the number of Incentive Stock Options and/or Nonqualified Stock Options to be granted to each Eligible Employee or Director and to prescribe the terms and conditions (which need not be identical) of each Option, including the purchase price per Share subject to each Option, and to make any amendment or modification to any Agreement consistent with the terms of the Plan;

(ii) to select those Eligible Employees and Directors to whom Awards shall be granted under the Plan and to determine the amount of Shares payable, the number of SARs, Performance Units, Performance Shares, RSUs, and/or shares of Restricted Stock, to be granted pursuant to each Award, the terms and conditions of each Award, including the restrictions or performance criteria relating to such Award, the maximum value of each Award, and to make any amendment or modification to any Agreement consistent with the terms of the Plan;

(iii) to delegate to the Chief Executive Officer the authority to grant Options or Awards with respect to Shares to employees of the Company from a pool of Shares established by the Committee, provided that such grants are made in accordance with applicable law.

Provided, however, that the Board can exercise any of the powers set forth in this Section 3(b), subject to any limitations imposed by Code Section 162(m) or Rule 16b-3 under the Exchange Act.

(c) Subject to the express terms and conditions set forth herein, the Committee shall have the power from time to time:

(i) to construe and interpret the Plan and the Options and Awards granted thereunder and to establish, amend and revoke rules and regulations for the administration of the Plan, including, but not limited to, correcting any defect or supplying any omission, or reconciling any inconsistency in the Plan or in any Agreement, in the manner and to the extent it shall deem necessary or advisable to make the Plan fully effective, and all decisions and determinations by the Committee in the exercise of this power shall be final, binding and conclusive upon the Company, a Subsidiary, and the Optionees and Grantees, as the case may be;

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(ii) to determine the duration and purposes for leaves of absence which may be granted to an Optionee or Grantee on an individual basis without constituting a termination of employment or service for purposes of the Plan;

(iii) to exercise its discretion with respect to the powers and rights granted to it as set forth in the Plan; and

(iv) generally, to exercise such powers and to perform such acts as are deemed necessary or advisable to promote the best interests of the Company with respect to the Plan.

(a) Subject to adjustment as provided in (d) below, the aggregate number of Shares which are available for issuance pursuant to Options or Awards under the Plan is Four Million Three Hundred Thousand (4,300,000) Shares. Except for Awards of Options or SARs, or Awards that must be settled in cash, the number of Shares reserved under the Plan that may be granted in the form of other Awards (“Full Value Grants”) will be counted against the 4,300,000 Plan maximum so that the maximum is reduced by one and one-half (1.5) Shares for each Share subject to the Full Value Grants . The number of Incentive Stock Options that may be issued under the Plan is up to 2,000,000. Shares to be issued under the Plan shall be made available from Shares currently authorized but unissued or Shares currently held (or subsequently acquired) by the Company as treasury shares, including Shares purchased in the open market or in private transactions.

(b) The following rules shall apply for purposes of the determination of the number of Shares available for grant under the Plan:

(i) If, for any reason, any Shares awarded or subject to purchase under the Plan are not delivered or purchased, or are reacquired by the Company, for reasons including, but not limited to, a forfeiture of Restricted Stock or termination, expiration or cancellation of an Option, Stock Appreciation Right, Restricted Stock Units, or Performance Shares (“Returned Shares”), such Returned Shares shall not be charged against the aggregate number of Shares available for issuance pursuant to Options or Awards under the Plan and shall again be available for issuance pursuant to an Option or Award under the Plan (with Returned Shares relating to Full Value Grants counting as 1.5 shares).

(ii) Each Performance Share awarded that may be settled in Shares shall be counted as one and one-half Shares subject to an Award. Performance Shares that may not be settled in Shares (or that may be settled in Shares but are not) shall not result in a charge against the aggregate number of Shares available for issuance. Each Stock Appreciation Right to be settled in Shares shall be counted as one Share subject to an Award, regardless of the number of Shares that are actually issued upon exercise and settlement of the Stock Appreciation Right. Stock Appreciation Rights that may only be settled in cash and may not be settled in Shares shall not result in a charge against the aggregate number of Shares available for issuance. In addition, if a Stock Appreciation Right is granted in connection with an Option and the exercise of the Stock Appreciation Right results in the loss of the Option right, the Shares that otherwise would

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have been issued upon the exercise of such related Option shall not result in a charge against the aggregate number of Shares available for issuance.

(iii) Each Restricted Stock Unit that may be settled in Shares shall be counted as one and one-half Shares subject to an award. Restricted Stock Units that may only be settled in cash and may not be settled in Shares shall not result in a charge against the aggregate number of Shares available for issuance.

(c) For purposes of Options or Awards to an individual who is a Named Executive Officer, the following rules shall apply to Options or Awards under the Plan:

(i) The maximum number of Options and Stock Appreciation Rights that, in the aggregate, may be granted pursuant to Awards in any one fiscal year of the Company to any one Participant shall be five hundred thousand (500,000).

(ii) The maximum aggregate number of Shares of Restricted Stock, number of Restricted Stock Units and Performance Shares or Units that may be granted pursuant to Awards in any one fiscal year of the Company to any one Participant shall be one hundred fifty thousand (150,000) Shares.

(d) In the event of any Change in Capitalization, the Committee shall make such adjustment in the number and class of Shares which may be delivered under the Plan, and in the number and class of and/or price of Shares subject to outstanding Options or Awards granted under the Plan, as may be determined to be appropriate and equitable by the Committee to prevent dilution or enlargement of rights; provided, however, that the number of Shares subject to any Option or Award shall always be a whole number and the Committee shall make such adjustments as are necessary to insure Options or Awards of whole Shares. Equitable adjustments shall be made by the Committee, as it determines are necessary and appropriate, in:

(i) the limitation on the aggregate number of Shares that may be awarded as set forth in Section 4(a), including, without limitation, with respect to Incentive Stock Options;

(ii) the limitations on the aggregate number of Shares that may be awarded to any one single Participant as set forth in Section 4(c);

(iii) the number and class of Shares that may be subject to an Option or Award, and which have not been issued or transferred under an outstanding Option or Award;

(iv) the Option Price under outstanding Options and Stock Appreciation Rights and the number of Shares to be transferred in settlement of outstanding Options or Stock Appreciation Rights; and

(v) the terms, conditions or restrictions of any Option or Award or Agreement, including the price payable for the acquisition of Shares; provided, however, that all such adjustments made in respect of each ISO shall be accomplished so that such Option shall continue to be an incentive stock option within the meaning of Code Section 422.

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Subject to the provisions of the Plan, the Committee shall have full and final authority to select those Eligible Employees and Directors who will receive Options and/or Awards; provided, however, that no Eligible Employee shall receive any Incentive Stock Options unless he is an employee of the Company or a Subsidiary (other than a Subsidiary that is a partnership) at the time the Incentive Stock Option is granted.

The Committee may grant Options in accordance with the Plan and the terms and conditions of the Option shall be set forth in an Agreement. Options may be granted based upon the achievement of such Performance Measures (as listed on Appendix A) as the Committee may determine and subject to such other terms and conditions as the Committee may specify. The Committee shall have sole discretion in determining the number of Shares underlying each Option to grant a Participant; provided, however, that in the case of any Incentive Stock Option granted under the Plan, the aggregate Fair Market Value (determined at the time such Option is granted) of the Shares to which Incentive Stock Options are exercisable for the first time by the Participant during any calendar year (under the Plan and all other incentive stock option plans of the Company and any Subsidiary) shall not exceed $100,000. Each Option and Agreement shall be subject to the following conditions:

(a) Purchase Price. The purchase price or the manner in which the purchase price is to be determined for Shares under each Option shall be set forth in the Agreement, provided, that the purchase price per Share under each Option (other than Acuity Brands Conversion Awards) shall not be less than 100% of the Fair Market Value of a Share on the date the Option is granted (110% in the case of an Incentive Stock Option granted to a Ten-Percent Stockholder).

(b) Duration. Options granted hereunder shall be for such term as the Committee shall determine, provided that no Option shall be exercisable after the expiration of ten (10) years from the date it is granted (five (5) years in the case of an Incentive Stock Option granted to a Ten-Percent Stockholder). The Committee may, subsequent to the granting of any Option, extend the term thereof, but in no event shall the term as so extended exceed the maximum term provided for in the preceding sentence.

(c) Non-Transferability. Unless the Committee otherwise provides for transferability in the Agreement, no Option granted hereunder shall be transferable by the Optionee, otherwise than by will or the laws of descent and distribution, and an Option may be exercised during the lifetime of such Optionee only by the Optionee or his guardian or legal representative. The terms of such Option shall be final, binding and conclusive upon the beneficiaries, executors, administrators, heirs and successors of the Optionee.

(d) Vesting. Subject to Section 6(h) hereof, each Option shall be exercisable in such installments (which need not be equal or the same for each Optionee) and at such times (which may include performance requirements) as may be designated by the Committee, but not less than a year from the grant date except as otherwise provided in the last sentence in this Section 6(d), and set forth in the Agreement. To the extent not exercised, installments shall

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accumulate and be exercisable, in whole or in part, at any time after becoming exercisable, but not later than the date the Option expires. The Committee may accelerate the exercisability of any Option or portion thereof at any time.

(e) Method of Exercise. The exercise of an Option shall be made only by a written notice delivered in person or by mail to the Secretary of the Company at the Company’s principal executive office (or in such other manner and to such other person or address as may be designated by the Committee), specifying the number of Shares to be purchased and accompanied by payment therefor and otherwise in accordance with the Agreement pursuant to which the Option was granted. The purchase price for any Shares purchased pursuant to the exercise of an Option shall be paid in full upon such exercise, as determined by the Committee in its discretion or as provided in the Agreement, in cash, by check, or by transferring Shares to the Company or by attesting to the ownership of Shares upon such terms and conditions as determined by the Committee. The written notice pursuant to this Section 6(e) may also provide instructions from the Optionee to the Company that upon receipt of the purchase price in cash from the Optionee’s broker or dealer, designated as such on the written notice, in payment for any Shares purchased pursuant to the exercise of an Option, the Company shall issue such Shares directly to the designated broker or dealer. Any Shares the Optionee transfers to the Company or attests to owning as payment of the purchase price under an Option shall be valued at their Fair Market Value on the day preceding the date of exercise of such Option. If requested by the Committee, the Optionee shall deliver the Agreement evidencing the Option to the Secretary of the Company who shall endorse thereon a notation of such exercise and return such Agreement to the Optionee. No fractional Shares shall be issued upon exercise of an Option and the number of Shares that may be purchased upon exercise shall be rounded to the nearest number of whole Shares.

(f) Rights of Optionees. No Optionee shall be deemed for any purpose to be the owner of any Shares subject to any Option unless and until (i) the Option shall have been exercised pursuant to the terms thereof, (ii) the Company shall have issued and delivered the Shares to the Optionee and (iii) the Optionee’s name shall have been entered as a stockholder of record on the books of the Company. Thereupon, the Optionee shall have full voting, dividend and other ownership rights with respect to such Shares.

(g) Termination of Employment. The Agreement shall set forth the terms and conditions of the Option upon the termination of the Optionee’s employment with the Company, a Subsidiary or a Business Unit (including an Optionee’s ceasing to be employed by a Subsidiary or Business Unit as a result of the sale of such Subsidiary or Business Unit or an interest in such Subsidiary or Business Unit), as the Committee may, in its discretion, determine at the time the Option is granted or thereafter, provided, however no Option shall be exercisable beyond its maximum term as describ