MACO limit from ALD

Hi Guys
I have to determine MACO carryover limits for a multi product facility.
For one API, I have NOEL and LOAEL toxicity values,
For the second API, I have an ALD (approx lethal dose) tox value.
Does anyone know how to use the ALD value to generate a MACO limit?

APIC guideline for cleaning will provide required information

Unfortunately APIC does not cover this, been down that avenue

Ok than calculate with tdd or based on toxicity or 10 ppm criteria and cosider lowest value as MACO


We have developed a MACO calculation software ( that addresses requirements of multi-product facilities. Just feed in the equipment and the product data and the application spits out a report. I can do a quick online demo, if this would be of interest to you.

Hi Cleman,

We do not support direct advertising on the forum…if you would like to take out an advert with us please contact me directly.


Its my mistake. Not cleman’s. Will keep that in mind from now onwards.

No problem @rmoorthy1 all good.

Using NOEL or ALD in no longer acceptable. It must be ADE (acceptable daily exposure, a function of toxicity). See Chapters 3 and 5 of the Eudralex.

In both cases you should use the ADE (a measure of toxicity derived from the NOAEL). Perform a ‘risk analysis’ and select the lowest ADE. Remember, it is your ‘cleaning procedures’ which are being evaluated using the MSC (maximum safe concentration, the new MACO) as a yardstick. See chapters 3 and 5 of the Eudralex.

1 Like