Thank you for your interest in using the resources created by PERC. Our goal is to create resources that are useful in advancing the protection of humans, communities, and ecosystems from the risk of pesticide poisonings, illness and injury. Further, we aim to help others implement activities and programs with the same objective(s).

We hope this information answers your questions about the use, distribution, and modification of PERC's works. If questions remain, please reach out to

Acceptable Use of PERC's Works:

  1. Linking to PERC Website and PERC's Works

    Anyone is welcome to post accurate information about PERC and links to PERC resources on websites, with appropriate attribution. No advanced permission is needed.


  2. Modifying PERC's Works

    PERC resources are intended to be used by others, and modification is acceptable within limits explained in 1-3 below.

    1. Some resources are required to be EPA-approved, and they carry an EPA Approval number that looks like this: EPA Worker PST 00017. Such resources may lose EPA approval if substantive modifications are made. See item (c) below.
    2. The PERC logo must be maintained on the modified material, and attribution given. For example, "This document/material is based on a publication that was developed by the Pesticide Educational Resources Collaborative (PERC), through cooperative agreement #X8-83616301 with the US EPA."
    3. Credits for photographs and illustrations must be maintained in their entirety.
    4. If the material is distributed, it must carry the same license that is described in Part d.


  3. Modifying PERC's Works that Require EPA Approval

    According to the newly revised Worker Protection Standard (WPS), some training materials must be EPA-approved. These are annual training materials for workers and/or handlers, and official training materials for instructors/trainers. Such materials are displayed with an EPA-approval number that looks like one of these examples:

    EPA approval W/H PST 00022
    EPA approval Worker PST 00010
    EPA approval Handler PST 00018
    EPA WPS TTT W/H 00026

    EPA's Office of Pesticide Programs offers the following preliminary guidance on modifications to EPA-approved training materials:

    • “Users of training materials MUST use the EPA-approved materials in their entirety and as they are provided, except as provided in the next paragraph. Changes to the content, the order of the information, or images in the presentation by a user may negate the approval for that specific use. However, users may present exercises, handouts, and additional images in their sessions to illustrate the points in the presentation (without adding these to the approved material). It is not necessary for EPA to review these additional materials, as EPA expects that they will not conflict with the original EPA-approved materials.
    • If a user determines that state- or region-specific information (such as crop specific images and information, or information about state/local regulations that modify those of the WPS) will enhance the presentation for their audiences, EPA prefers for those to be included separately, as described above. If it will be disruptive or impractical from a presentation standpoint (for example, to switch from one presentation to another), EPA agrees that slides — preferably as few as possible — may be added to the presentation. The added slides MUST have a statement that identifies the source, and the slide must look distinct from the EPA-approved materials. It is not necessary for EPA to review these slides, as EPA expects that they will not conflict with the original EPA-approved materials.”


  4. Distributing PERC's Works

    Most PERC publications carry the following copyright/license:

Commons License
    This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License by The Regents of the University of California, Davis campus, 2017. For information contact

    This license (see the license document for details) contains three main clauses that regulate the use of PERC's Works (Note: none of the following explanatory text may be construed as modifying the actual license whatsoever):

    1. Attribution:
      1. If you share or distribute a work, it must be properly attributed to PERC (see item "b." under "Acceptable Use" above, as well as "Section 3(a)" in the license for specifics and limitations.
    2. NonCommercial:
      1. NonCommercial means not primarily intended for or directed towards commercial advantage or monetary compensation.
      2. This clause does not rely on the "Non Profit" or "For Profit" status of the user of PERC's works, but instead relies on the use of the work itself. PERC generally considers a user's minimal monetary compensation to cover distribution and operating costs as allowable under this clause. Please note that a "For Profit" entity would need to strongly consider the ramifications of the "ShareAlike" clause as explained in item 3) below, before modifying or distributing PERC's Works.
      3. A more detailed (although not legally binding) interpretation of this clause is available here.
    3. ShareAlike:
      1. If you adapt PERC's Works into new material ("Adapted Material" — see "Section 1(a)" of the license), you must license that material under this same "Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License." See "Section 3(b)" in the license for details.


  5. Example Uses

    Examples of acceptable potential uses of PERC's Works under this license (Note: none of these examples may be construed as modifying the actual license whatsoever):

    Examples of what PERC typically considers acceptable use:

    • Printing and distributing a PERC document at minimal or no cost to the recipient(s).
    • Using a PERC presentation during a training event, where participants attend at little-to-no cost.
    • Adding PERC materials to mail-outs at no additional cost to the recipient.
    • Using a PERC presentation or document as the basis for a new presentation or document with proper attribution, as long as the adapted presentation is licensed under the CC-BY-NC-SA license.

    Examples of what PERC typically considers unacceptable use:

    • Using a PERC presentation or document as the basis for a new presentation or document where recipients are charged excessive fees, and/or the adapted presentation is not licensed under the CC-BY-NC-SA license.
    • Printing and distributing PERC document(s) in exchange for excessive fees/funds from recipient(s).
    • Showing a video that was produced by PERC at an event where participants are charged an excessive fee to attend.


  6. Additional Permissions to Use PERC's Works

    If your organization would like to use PERC's Works in a way that generates revenue, or are otherwise concerned that a potential use may infringe on any clauses of the license, please contact for more information.