TOXMAP® is a mapping tool developed by the US National Library of Medicine (NLM) that uses maps of the United States and Canada to help users visually explore data primarily from the US EPA's Toxics Release Inventory (TRI) and Superfund Program.

There are two versions of TOXMAP: the beta (or pre-release) of an Adobe® Flash-based version, and TOXMAP classic. This FAQ will help you decide which version of TOXMAP to use.

TOXMAP lets you:

  • Browse TOXMAP data, including zooming and panning the map and clicking on points on the map for details;
  • Zoom the map to specific locations including city/state/ZIP or named places;
  • Search TOXMAP TRI and Superfund data, including by chemical;
  • Overlay demographic data including from the US Census;
  • Obtain chemical information from authoritative sources, including NLM; and
  • Get Help.

Read more about TOXMAP, its data sources, accessibility, or check out the TOXMAP Fact Sheet.

  • This Help pertains to the beta (or pre-release) of a new version of NLM's TOXMAP. The beta continues to evolve, so in some cases what you see and read here may not exactly match what you find when you use TOXMAP.
  • TOXMAP lets you explore toxic chemicals released into the environment by certain industries and present in hazardous waste sites. The US EPA collects and maintains this data (see more about TOXMAP data).
  • You can browse all TOXMAP facilities, zoom the map to a particular location, or search for facilities or chemicals in a city, state, or ZIP code. You can get information on chemicals, including effects on human health and exposure to chemicals in the workplace. You can also see demographic data color-coded at the county level.
  • Explore the map by clicking and dragging the mouse, by using the mouse wheel, by using the Zoom Control in the upper left corner, or by holding down the Shift key and drawing a rectangle on the map.
  • After you've completed a Search, switch between viewing search results and browsing all facilities via the Map Contents side panel.
  • You can collapse the Map Contents and Search Results side panels with the arrow icons (leftward facing arrow icons) in the corner--this leaves more room for your map.
  • TOXMAP works best at higher screen resolutions, with your web browser set to fill the entire screen. It is not recommended for small screens, very slow computers, or slow or unreliable Internet connections. In these cases, try TOXMAP classic.
  • For more information, see other areas of this Help, or try these other help resources for TOXMAP.
  • We value your feedback! Please contact us and tell us what you think of the new TOXMAP.

TOXMAP has a rich user interface that takes some time to become familiar with. The most prominent area of TOXMAP is the map itself. The map contains the following elements that are always present:

  • Background map data called a base map (which includes roads, landmarks, political boundaries, etc.),
  • The Zoom Control in the upper-left corner for zooming and panning your map,
  • The map scale in the lower-left corner that updates as you zoom the map, and
  • The base map selector (see image) that switches the base map between Streets, Aerial (satellite), and Topographic (terrain).
base map selector
For more information on these elements, see using the map. The map also shows TOXMAP data including map layers listed in the Map Contents side panel, search results obtained from using the Search window, and overlays of demographic data layers.

The toolbar occupies the top of the TOXMAP user interface. It contains icons (see image) to display TOXMAP windows (Search, Bookmarks, etc.), an icon to return to the TOXMAP home page, and an icon to bring up the Welcome window.

TOXMAP toolbar icons

Most windows in TOXMAP can be moved by clicking and dragging the window. They can also be minimized into icons via the minimize icon in the upper-right of the window, next to the close icon. Windows and their icons can be positioned almost anywhere on the screen (see image). Side panels can be collapsed to allow a larger view of the map or search results.

moveable window icons

The Welcome window is TOXMAP's starting point. It contains key information on TOXMAP datasets (with links to the Glossary and FAQ), and basic instructions. If you are unfamiliar with TOXMAP and its data, be sure to review this information. The Welcome window then invites you to choose what you want to do with TOXMAP. The choices it presents roughly correspond to the toolbar icons along the top center of the screen. If you don't understand all of the choices, just click the Go button and start browsing TOXMAP data.


                       welcome icon          What do you want to do with TOXMAP?

You can always get back to the Welcome window by clicking on the Welcome icon in the upper right corner of TOXMAP.

The easiest way to use the map it to click on it and drag it with the mouse:

  • Left-clicking and dragging the map will pan the map in any direction;
  • Scrolling the mouse wheel will zoom the map in and out, anchoring it at the location of the mouse pointer;
  • Holding down the Shift key and drawing a rectangle on the map will zoom to the area of this rectangle.

As you use TOXMAP, keep in mind that the Start Over button begins a new TOXMAP session and clears all searches. The Welcome icon in the upper right of the screen returns you to the Welcome window but keeps your current map intact.

TOXMAP works best at higher screen resolutions, with your web browser set to fill the entire screen. If you need more space for your map, collapse the Map Contents and/or Search Results side panels.

The Zoom Control (see image) provides alternative ways to manipulate the map.  As you move the map, it always remains located in the upper-left corner of the map.  The Zoom Control has the following functions:

  • Pan the map in increments in any of the eight cardinal directions;
  • Zoom to the lower 48 (contiguous) United States;
  • Zoom the map in increments with the plus and minus icons;
  • Zoom the map to a specific level by clicking and dragging the zoom slider--the current map scale will appear as you click and drag the slider; and
  • Cycle through your map history--each time you pan or zoom the map, the location is added to your map history; with the Previous Map and Next Map buttons, you can zoom the map to previous locations.
annotated zoom control widget

The Zoom to Location window zooms the map to a specified address, place, or map coordinate. It is available from both the Welcome window and the toolbar. It can be used when browsing TOXMAP data or after performing a search. The Address tab at the top of the Zoom to Location window allows text entry of street address, place, city, state/province, ZIP code, and country (US and Canada only). A "place" is a common name of a location, such as the name of a county, school, hospital, Indian reservation, or other landmark. To find a place only in a given state, enter a place name and a state. In general, providing more information gives fewer results, but is more likely to contain what you're looking for. The Coordinates tab allows entry of precise x-y geographical coordinates (latitude/longitude).

When you click the Zoom to button, the window will switch to the Results tab which displays a scrollable list of results (or matches). The map zooms to the first item in the list (if any), and indicates its location on the map. Click items in the list to zoom to other results, or delete them with the red "x". Closing the Zoom to Location window will remove the location indicator, but will preserve your most recent results for the next time you bring up the window. Select one of the other items in the list to zoom to a different location.

From the Welcome window, select Browse TOXMAP to view TRI, Superfund, and other data layers. These layers can be toggled on and off via checkboxes in the Map Contents side panel. Pan and zoom the map with the mouse or with the Zoom Control in the upper left corner of the map, or select Zoom to Location from the toolbar. Click points on the map to pop up details, then click more... to see chemical release amounts and other details.

When a user is browsing, search results are unavailable. To restore search results, click the Show Search Results radio button in the Map Contents side panel. To return to browsing data, click the Browse TOXMAP radio button (see image).


browse and search radio buttons

The Map Contents side panel provides several important user interface elements. The most prominent section of Map Contents is the expandable list of checkboxes often called the "Table of Contents". The checkboxes toggle individual layers of TOXMAP data on and off--including TRI facilities, Superfund sites, and other layers like commercial nuclear power plants. Note that there are two separate TRI layers--one which shows all facilities for all TRI years, and another which shows only those facilities that reported to EPA in the most recent TRI year. Some layers can be expanded and collapsed with the [+] and [-] icons (plus and minus).

Once you have initiated a search, the Table of Contents disappears, and another radio button appears in Map Contents labeled Show Search Results. This radio button, along with the Browse TOXMAP radio button, switch the user between browsing TOXMAP data and searching it (including viewing search results). You can also switch between browsing and searching by making selections on the Welcome window.

Once you have overlaid demographic data (such as from the US census), an additional checkbox appears at the top of the Map Contents side panel labeled Show Demographic Data. This checkbox toggles on and off the most recently displayed demographic layer and its legend in Map Contents. Mouse over colored rectangles in the legend to see the numeric range for that color on the map--lighter green ranges indicate lower values; darker blue ranges indicate higher values.

To gain more map area, Map Contents can be collapsed with the Hide icon in the upper right of the panel (The Hide icon ), and restored by clicking on the resulting narrow, vertical collapsed panel.

The Map Contents side panel with Hide icon

In TOXMAP, "Search" refers to searching the TRI and/or Superfund dataset(s), which brings up the Search Results side panel. This is in contrast to Browse in which you turn map layers on and off via the Map Contents side panel. In both cases, you can move the map, zoom to a location, or click on any of the other toolbar icons.

If you prefer a video to text and images, a YouTube tutorial entitled "Searching TOXMAP by chemical" shows you how to use the TOXMAP chemical search feature.

When a user is entering a search or viewing search results, browsing TOXMAP data is unavailable-- that is, the list of checkboxes (often called the "Table of Contents") on the Map Contents side panel is hidden so that layers cannot be toggled on and off. To return to browsing data, click the Browse TOXMAP radio button in the Map Contents side panel. To restore search results, click the Show Search Results radio button.

Browse and Search radio buttons

The Search window searches TRI and/or Superfund data based on your search criteria. It is available from both the Welcome window and the toolbar. Enter your search criteria (for example, chemical name, city, and state), then click the Search button to submit your search.

If there are results, they will be displayed as icons on the map and as a list on the Search Results side panel. Click icons on the map or entries in the list to pop up details, then click more... to see chemical release amounts and other details. Some searches will be cut off at 1,000 results. If you enter a state or ZIP code, then only results in that state will be shown. If you selected the TRI dataset and entered a chemical name, then on-site releases of the specified chemical and selected year (or years) are shown. Otherwise, all facilities that reported to TRI are shown. For Superfund searches, hazardous waste sites containing the specified contaminant (if any) are displayed.

Results of a search are listed in a table on the Search Results side panel. To gain more map area, the entire panel can be collapsed with the Hide icon in the upper right of the panel (see image), and restored by clicking on the resulting narrow, vertical collapsed panel. Tabs along the top of the panel select results from different datasets (for example, TRI or Superfund). A short description of the map displays the following:

  • The number of displayed search results
  • The number of search results that are visible on the current map-- pan and zoom the map to see more results
  • The number of facilities that matched your search criteria (if not all results are displayed)
  • The number of on-site chemical releases represented by the facilities in your search results. If a search included more than one year, or if any facilities submitted more than one report per year for a given chemical, then the number of chemical releases will exceed the number of reporting facilities.
  • The chemical name, if one was selected on the search window. Clicking on the name will bring up the Chemical Information window with links to authoritative sources about the chemical.

part of Search Results side panel

Below the map description, a legend displays icons that correspond to the search result icons on the map. The list of displayed search results currently on the map appears in a scrollable table ordered by release amount (for TRI) or alphabetically (for Superfund). Click on table headers to reverse the order of entries in the list. Mouse over entries to highlight them on the map, or click on the entry to pop up details, then click more... to see chemical release amounts and other details.

The US Census & Health Data window overlays county-level color-coded demographic layers on the map. It is available from both the Welcome window and the toolbar. The window is divided into several tabs each of which corresponds to a category of demographic data--for instance, population or race data from the US Census. Each of these tabs contains one or more lists of selectable layers. Some tabs (e.g., Race) contain subtabs that further subdivide the demographic category. In all cases, select a layer name to display it on the map along with a colored legend in the Map Contents side panel. The layer (and its legend) can be toggled on and off via the Hide Demographic Data button or via the Show Demographic Data checkbox in Map Contents. Mouse over colored rectangles in the legend to see the numeric range for that color on the map--lighter green ranges indicate lower values, whereas darker blue ranges indicate higher values.

Please note:

  • You can view only one demographic layer at a time.
  • Sometimes TOXMAP data (such as TRI facilities) are hard to see when a demographic layer is displayed. Toggle the demographic layer on and off with the Show Demographic Data checkbox in Map Contents.
  • For the most part, these are county-level nationwide layers. You may need to zoom out to see more than one county.
  • US Census layers from 2000 and 2010 are displayed at the census tract level when sufficiently zoomed in.

The Chemical Information window provides links to authoritative sources about the chemicals found in TOXMAP. It is available from the Welcome window, the toolbar, and the Search Results side panel (if a chemical was searched). The window is divided into three tabs:

Bookmarks zoom the map to a pre-set location. You can also save and name your current map area as a bookmark so that you can zoom to it later. Only the map area is preserved, not the data on the map such as TRI facilities and search results. Bookmarks are saved only on your local computer and will appear in the list the next time you bring up TOXMAP with the same web browser. The bookmarks can only be accessed from within TOXMAP and are not the same as web browser bookmarks in Firefox or Chrome (called "favorites" in Internet Explorer).

The Bookmarks icon on the toolbar brings up the Bookmarks window. Click an entry in the Bookmarks List to zoom the map to a pre-defined or user-defined geographical area. The exact area shown on your map will depend on the size and shape of the map (as determined by your browser window and presence of side panels).

To create your own bookmark, first zoom the map to the area you wish to save, then click the Add Bookmark tab at the top of the Bookmarks window. Name the bookmark in the text area, then click the Add Bookmark button. Now it is available in the Bookmarks List and can be used like any other TOXMAP bookmark. To delete the bookmark, click on the red "x" next to the bookmark's name in the list.

The Print icon on the toolbar brings up a simple print window for printing your TOXMAP maps. Optionally enter a title, then decide if you want to print the entire screen (with all windows, side panels, etc.), or just the map itself, including the pop-up details window. Clicking the Print button will bring up a standard Print dialog for your computer where you can select a printer and change printer-specific settings.

There are several other ways to learn about TOXMAP, its data, and environmental health: