How to search for information with eChemPortal

 

Overview

To access information in eChemPortal you can search on:

  • A substance.
  • A substance and then on specific property criteria.
  • Property criteria.
  • Property criteria and then on a specific substance.

To access data for a specific substance, a search by number is recommended. Nevertheless, eChemPortal allows you to search by chemical names and synonyms in several of languages and even trade names (see “Substance searches”). The search engine of eChemPortal permits searches of partial names using a wildcard (*).

 

Not all data sources can be searched through the property search. (see list).

 

Some participating data sources have submitted to eChemPortal only information on substance identification and web links to information/documents on their local systems. Some data sources have submitted searchable property data in addition to substance identification and web links. See how not to limit your search.

Below is guidance on how to efficiently use the search facilities of eChemPortal.

 

Note: The number of chemicals referenced in eChemPortal is limited to those chemicals for which information exists in the participating databases. If you search for a chemical for which no information exists in the participating databases, you will receive the message "The search returned no results".

Substance Search

Number searches

To access data for a specific substance, you can enter a CAS, EC, IUBMB, MITI, UN or NA Number in the “Number” search field. Search by CAS Registry Number is recommended. Every record does not have every kind of number associated with it.

Partial number searches or searches using the character "*" as a wildcard, are not permitted when searching by number. 

Full name searches

You can enter the full name of a chemical in the “Chemical name or synonym” search field, e.g. "Glutaric acid" and the search engine will retrieve the link for the entries of "Glutaric acid".

This search is not case sensitive, i.e. the search string "glutaric acid" will also retrieve "Glutaric acid".

eChemPortal also recognises chemical names or synonyms in several languages. For example searching for the Japanese name of "Carbon tetrachloride" i.e. "四塩化炭素" will retrieve the link for the entries of "Carbon tetrachloride". Every record does not have name in different languages and trade names associated with it. See more information on the synonyms, names in different languages, and trade names stored in eChemPortal.

Partial name searches

In case you only have an incomplete name or want to find several substances which share parts of a name, you can enter partial names.

The character "*" is used as a wildcard. For example the search string "*tert-butylphenol*" will retrieve all chemicals that have a name or synonym containing the characters "tert-butylphenol", e.g. "2,2'-Methylenebis(4-methyl-6-tert-butylphenol)monoacrylate", "2,4,6-tri-tert-butylphenol",  etc. Or the search string "*tert-butylphenol" will retrieve all chemicals that have a name or synonym finishing with the characters "tert-butylphenol" e.g. "2,4,6-tri-tert-butylphenol", "2,4-di-tert-butylphenol",  etc. The search string "*tert-butyl*methylbenzene*" will find 1-tert-butyl-4-methylbenzene, etc.

The minimum length of a search string for names is at least two subsequent characters (non-wildcards).

Synonyms, names in different languages, trade names

In addition to a substance name, participating data sources can submit to eChemPortal synonyms, trade names and names in foreign languages associated with specific chemical names. In a search by “Name”, eChemPortal searches through these names in addition to the name the data source indicates as the substance name.

As well, in order to improve substance searches the eChemPortal contains an index of synonyms and trade names that have not been directly submitted by participant data sources.

Every record does not necessarily have associated names in different languages, i.e., because some substances are associated with a Japanese name, it does not mean that all substances stored in eChemPortal are associated with a Japanese name. It is recommended to search in English. However, in a search on substance, the search mechanism finds substances potentially related to your search criteria in records not containing associated synonyms by searching for the association in other records. (See how the substance search mechanism works below.)

Filter by type of information

You may filter your substance search down to results linking to specific databases by clicking on the "Filter by type of information" on the Substance Search page. You can then either choose a specific type of information, for example "Property information", "Exposure and use information", or "GHS classifications", or choose specific databases.

The types of information that can potentially be found in participating databases reflect those information types that can be found in across the entire database. It does not mean that every record in the participating databse includes infromation on all types listed.

How the substance search mechanism works

 

Progressive searches

The search engine in eChemPortal performs a progressive three level search for chemical substances.

In order to help the user find the desired chemical, this progressive search is always performed. The reliability of the three levels depends on the search criteria that the user enters; this means that the first level results should not be considered better than the second level or third level results.

Below is an explanation of the three levels of subsequent searches:

 

1. First level results:

In the first level, the search criteria specified by the user is used to search in eChemPortal.

 

2. Second level results:

In the second level, the results from the first level are used as the starting point to perform this second step of the search. This means that the first level results are used as subsequent search criteria.

 

3. Third level results:

In the third level, the results from second level search are used as search criteria.
The figure below illustrates the mechanism for a search using a Criteria 1 (eg. CAS number)

 

Note: If the search criteria finds a chemical name (A) which is considered a synonym of a chemical name (B), then, in the search results, only the chemical name (B) will be displayed in the search results and not the synonym (A).

In order to improve substance searches eChemPortal also contains an index of synonyms and trade names that have not been directly submitted by participant data sources. Though these names are used to perform the progressive search, they will never be displayed in the results area.

If name and number are searched on at the same time, no progressive three level searches for chemical substances are performed.

 

Displayed results

 

Search Result Step 1

The results for each level are indicated with the following symbols: first level , second level , third level.

The following figure explains what is displayed in the result table and how results can be selected to be carried over to the next result page.

 

 

Search Result Step 2

The subsequent result screen allows you to click a link in the "Result" column to see the information related to that substance in the participating data source.

You can also select one or several substances in the "Check" column and click “Continue with a Property Search” in order to search on specific property data for those substances.

 

 

Note: If eChemPortal does not contain any queriable property data for a particular participating data source, the check box is deactivated for that source.

Property Search

Specifying search criteria

After choosing results in a substance search, you can search specific property criteria of the substances selected.  You can also skip the substance search and go straight to the property search without specifying substances. You may then also choose to limit the property search to particular Participating Databases.

 

Note: Not all data sources can be searched through the property search (see list). Substances in the substance result list from a data source that did not submit property data to eChemPortal cannot be chosen for a property search (no checkbox is displayed). If you go straight to the property search without specifying substances, only data from data sources that submitted property data to eChemPortal will be searched.

 

Select Query Block Type

In the property tree, choose a property and then define the search criteria for this property in its query block screen.

You can add up to 10 further “basic query blocks” to the initial query by clicking .

Delete query blocks by clicking on  next to the block name.

The query blocks can be combined with the operators “AND”, “OR”, and “NOT”.

You can change the execution order by clicking on to reorder query blocks and increase or decrease the level of the blocks by clicking on . Increasing or decreasing the level of the blocks influences the conjunction logic. The conjunction logic is performed between the blocks that are decreased together before they are executed against the other query blocks.

 

Define search criteria

You can define search criteria by choosing values from pop-up lists, entering a date, or entering a numerical value.

 

Note: If no search criterion is chosen for a query block, all substances records containing that endpoint will be displayed.

Pop-up list fields

Click on  to the right of the field to see the list of values you can select. For list fields it is possible to choose multiple values. A separator an “|” automatically separates the values. The maximum number of characters (2000) which can be entered into a single search value field limits the multiple selection searches. If you select “Other” in a list field, you can then enter in the field for that property a search value not included in the list.

Date fields

For data fields, you can specify a search operator and a search value.

Numerical fields

For numerical fields, the value, the search operator and the unit can be specified. See Querying in numeric ranges for an explanation on querying in ranges. See Unit conversion rules for an explanation on how units are searched. If you choose “Other” in a unit field, you can enter a unit that is not in the list in the field to the right of the unit field.

 

Note: The query logic for the search criteria skips fields for which no value was entered. All fields within a single query block are combined with an AND-operator. All multiple selection fields will be combined with the OR-operator.

 

Execute the Query

Finally when you have defined all of your query blocks, clicking  displays the result screen. Before you click the “Execute Query” button, you can view the criteria selected by clicking on  on the right of the property query block.

 

Save / Load Query

You can also save the entered query parameters on your local system for later re-use by clicking on  or load previously saved query parameters by clicking on .

Unit conversion rules

eChemPortal stores the original value and unit of endpoint property data submitted by a Participant Database. In addition, in order to simplify query and retrieval procedures, eChemPortal also stores numerical units in a standard unit where possible, thus allowing a search on one unit to find the equivalent value in another unit. For example a search on a value in Celsius can retrieve results in Fahrenheit. The original value and unit submitted by a Participant Database is always displayed in the search results.

The following table lists the standard unit and unit conversion rules used in eChemPortal.

 

Description

Formula

C ==> K

X+273.15

F ==> K

(X+459.67)/1.8

 

 

ng/kg sediment dw  ==>  mg/kg sediment dw

X/1000000

µg/kg sediment dw  ==>  mg/kg sediment dw

X/1000

ng/L ==>  mg/L

X/1000000

µg/L ==>  mg/L

X/1000

 

 

min ==> h

X/60

d ==> h

X*24

wk ==> h

X*7*24

 

 

ng/L ==> mg/L

X/1000000

µg/L ==> mg/L

X/1000

g/L ==> mg/L

X*1000

µmol/L ==>  mol/L

X/1000000

mmol/L ==>  mol/L

X/1000

 

 

g/kg soil d.w. ==> mg/kg soil d.w.

X*1000

kg/ha ==> g/ha

X*1000

lbs/acre (international acre) ==> g/ha

X*1120.85115619

 

 

min ==> h

X/60

d ==> h

X*24

wk ==> h

X*7*24

mo ==> h

X*30*24

 

 

min ==> h

X/60

d ==> h

X*24

 

 

d ==> h

X*24

wk ==> h

X*7*24

mo ==> h

X*30*24

 

 

g/ha ==> mg/cm²

X/100000

 

 

g/ha ==> mg/cm²

X/100000

 

 

min ==> h

X/60

d ==> h

X*24

wk ==> h

X*7*24

mo ==> h

X*30*24

yr ==> h

X*365*24

 

 

s-1 ==> h-1

X*60*60

min-1 ==> h-1

X*60

d-1 ==> h-1

X/24

a-1 ==> h-1

X/365/24

 

 

hPa ==> Pa

X*100

kPa ==> Pa

X*1000

atm ==> Pa

X*101325

Bar ==> Pa

X*100000

mBar ==> Pa

X*100

mmHg (= Torr) ==> Pa

X*101325/760

PSI ==> Pa

X*6894.75729316836

Torr (=mmHg) ==> Pa

X*101325/760

 

 

µg/L ==> mg/L

X/1000

g/L ==> mg/L

X*1000

g/cm³ ==> mg/L

X*1000000

kg/m³ ==> mg/L

X*1000

 

 

atm m³/mol ==> Pa m³/mol

X*101325

 

 

µg/L ==> mg/L

X/1000

g/L ==> mg/L

X*1000

g/cm³ ==> mg/L

X*1000000

kg/m³ ==> mg/L

X*1000

g/kg solvent ==> mg/100 g solvent

X*100

 

 

kg/m³ ==> g/cm³

X/1000

g/L ==> g/cm³

X/1000

 

 

N/m ==> mN/m

X*1000

 

 

µm ==> mm

X/1000

 

 

µg/L ==> mg/L

X/1000

g/L ==> mg/L

X*1000

mmol/L ==> mol/L

X/1000

µmol/L ==> mol/L

X/1000000

pg/m³ air ==> pg/L air

X/1000

µg/m³ air ==> µg/L air

X/1000

mg/L air ==> µg/L air

X*1000

mg/m³ air ==> µg/L air

X

 

 

µg/kg bw d.w. ==> mg/kg bw d.w.

X/1000

µg/kg bw w.w. ==> mg/kg bw w.w.

X/1000

 

Querying in numeric ranges

In the OECD harmonised templates numeric values are often entered as ranges. When querying for numeric values you have to specify an upper and a lower values. Your specification controls how two numerical intervals are compared with each other.

 

 
entered data
graphical illustration
Search for
10 .. 20
0 ---------xxxxxxxxxxx---------- 30
 
10 .. [  ]
0 ---------xxxxxxxxxxxxxxxxxxxxx 30
 
[  ] .. 20
0 xxxxxxxxxxxxxxxxxxxxx--------- 30
 
20 .. 20
0 --------------------x--------- 30
 
 
 
Sample: Ranges overlapping
 
 
Search for
10 .. 20
0 ---------xxxxxxxxxxx---------- 30
Finds
20 .. 20
0 -------------------x---------- 30
 
5 .. 15
0 ----xxxxxxxxxxx--------------- 30
 
15 .. 20
0 --------------xxxxxx---------- 30
 
18 .. [  ]
0 ------------------xxxxxxxxxxxx 30
 
[  ] .. 12
0 xxxxxxxxxxxx------------------ 30
 
 
 
Sample: Ranges fully including
 
 
Search for
10 .. 20
0 ---------xxxxxxxxxxx---------- 30
Finds
20 .. 20
0 -------------------x---------- 30
 
5 .. 15
0 --------------xxxxxx---------- 30
But does not find
15 .. 20
0 ----xxxxxxxxxxx--------------- 30
 
18 .. [  ]
0 ------------------xxxxxxxxxxxx 30
 
[  ] .. 12
0 xxxxxxxxxxxx------------------ 30
 
 
 
Sample: Ranges only exact match
 
 
Search for
10 .. 20
0 ---------xxxxxxxxxxx---------- 30
Finds
10 .. 20
0 ---------xxxxxxxxxxx---------- 30
But does not find
20 .. 20
0 -------------------x---------- 30
 
5 .. 15
0 --------------xxxxxx---------- 30
 
15 .. 20
0 ----xxxxxxxxxxx--------------- 30
 
18 .. [  ]
0 ------------------xxxxxxxxxxxx 30
 
[  ] .. 12
0 xxxxxxxxxxxx------------------ 30

How not to limit your search

 

Do not search on name and number at the same time.

When you search on name and number at the same time, no progressive three level searches for chemical substances are performed. See How the substance search mechanism works.

 

Do not deselect data sources.

You may want to see results only from particular data sources, in which case you can deselect the other data sources in the search window. Please keep in mind however, that in a search on substance, the search mechanism finds substances potentially related to your search criteria in records not containing associated synonyms by searching for the association in other records. The search mechanism will not search for name, synonym or number associations in records of data sources that you have deselected.

 

Check to see which databases contain queriable property data.

Not all data sources can be searched through the property search. Some participating data sources have submitted to eChemPortal only information on substance identification and web links to information/documents on their local systems because they did not have the capacity to provide property data (For example, their information exists in a PDF document and not in a database format.)

If you are interested in property data for a specific chemical, do a substance search on that chemical to obtain all the information on that chemical available through eChemPortal.

 

Do not enter a search criteria after "other:".

Some “other:” fields in the property search do not take search criteria. It is best to also try searching on "other:" fields without entering search criteria after the text "other:".

 

Do a substance search from the property results.

If you are interested in a specific property value, do a property search. You may then want to do a search by substance on the substances found through the property search, by clicking on the substance name in the results lists. The substance searches may lead to information of interest such as other datasets (in a non-database format) on those substances.

 

GHS search

The GHS search allows users, for an individual chemical, to view GHS classifications which have undergone a review by a regulatory body or intergovernmental organisation and offers direct links to the full information in the participating data sources.

In order to find harmonised classification information, you may proceed two ways: search harmonised classification and labelling for a specfic substance or perform a search directly on the GHS search page.

GHS search for a specific substance 

From the substance search page

First, in order to access GHS information on a specific substance, you may search by substance number (or name), then, click on the overall query results to view the below table:

 

 

From the GHS search page

 

On the “Classification and labelling search” page you may provide either a substance number or a substance name and click search. Then by clicking on the overall query results link, you will access directly all the harmonised/reviewed classification and labelling information available for that substance. 

In the table "Other classification and labelling information", you can access data sources that may contain C&L information for a substance, whether harmonised or self-classified.

 

Finally you may access additional information in the database by clicking on the result icon.

 

Search directly on classification on the GHS search page

The second possibility is to search directly by classification. For this you don't specify any substance but you will select the classification of your interest in the query block.

 

Then you click add to create your query block. You may combine several query blocks to find multiple classifications.

 

 

 

In the results page you will have all the classifications and labelling relevant to your search, and in this example, that have at least dermal and oral acute toxicity harmonised classification.

 

Structure search

In order to find information via eChemPortal for a chemical substance whose chemical name is unknown or to find information on chemical substances with a similar structure to a specific chemical, the OECD QSAR Toolbox may used.

 

Video tutorials

This tutorial explains how to perform a property search on a specific chemical in eChemPortal.
This tutorial explains how to find GHS classification information on a specific chemical in eChemPortal.
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