Enter LC50 Values for Raw Materials

This is a brief guide to entering LC50 values for raw materials on to Formpak to facilitate mixture calculations for inhalation toxicity relating to GHS and Safety Data Sheets.

Background in GHS

GHS refers to different types of airborne ‘stuff’: gases, vapours, dusts/mists. The units in GHS for these different forms are gases ppmV, vapours mg/l and dusts/mists mg/l.

The calculation to estimate the ATE Inhalation requires the airborne form and the units are consistent with GHS.

The LC50 data available in literature and from suppliers can be presented in different units. So, when adding LC50 data into Formpak you need to know what type of airborne form the data relates to and check the units used. If required, you need to convert values to be consistent with the units used in GHS.

In the calculation of inhalation toxicity of a mixture:

if there are measured LC50’s available for raw materials in the mixture, these values are expected to be used.
if there is no measured LC50, but there is an assigned category, e.g. Acutely Toxic by Inhalation category 3 (ATI3), then an Assumed Toxicity Estimate ATE is assigned.

Note:The ATE is set around the 10th percentile in the range for the category, so conservatively low but not the worst case.

Enter LC50 Data for Raw Materials into Formpak

1. If you have LC50 data, check:

What airborne form does the LC50 data relate to? Gas, vapour or dust/mist?
Which units are used? Are they the same units as in GHS?

If needed, convert values to relate to the same units

2. In Formpak, for the raw material (at regulatory level*):

Enter the LC50 value into property ‘LC50 Inhalation’
Select the airborne form in property ‘LC50 Inhal Route’
In absence of LC50 value, but if you have a classification e.g. Acutely Toxic by Inhalation category 3, then add the property with a value of Yes for the appropriate property e.g. ATI 3 = Yes

Example Raw Material with an LC50 of 5.1 for Vapour route