Minn. R. agency 144, ch. 4717, CANCER INDEX AND HAZARD INDEX, pt. 4717.8550

Current through Register Vol. 49, No. 24, December 9, 2024

Part 4717.8550 - PROCEDURE FOR DETERMINING CANCER INDEX FOR SIMULTANEOUS EXPOSURE TO MULTIPLE CARCINOGENS

Subpart 1.Cancer index.

To evaluate simultaneous exposure for multiple carcinogens, a cancer index must be calculated using the procedure in this part.

Subp. 2.Carcinogenic HRVs.

For health risk values (HRVs) that have cancer endpoints, items A to C apply.

A. A cancer index is determined for chemicals or defined mixtures of chemicals with an inhalation endpoint of cancer using the following equation:

Cancer index =

EC1 _____ HRVC1

+

EC2 _____ HRVC2

+ +

ECn _____ HRVCn

Where:

(1) E_Cn represents the measured or modeled ambient air concentration as expressed in units of micrograms per cubic meter ( µg/m³) of the first, second, through the n^th carcinogen; and

(2) HRV_Cn represents the chronic HRV of the first, second, through n^th carcinogen as expressed in units of micrograms per cubic meter ( µg/m³).

B. A cancer index of one is equivalent to a cumulative HRV. A cancer index greater than one exceeds the cumulative HRV.

Subp. 3.Carcinogenic MHRVs.

For mixtures of multimedia health risk values (MHRVs) that have cancer endpoints, items A to C apply.

A. A cancer index is determined for chemicals or defined mixtures of chemicals with an endpoint of cancer using the following equation:

Cancer index =

DC1 _____ MHRVC1

+

DC2 _____ MHRVC2

+ +

DCn _____ MHRVCn

Where:

(1) D_Cn represents the calculated lifetime averaged daily dose of the first, second, through the n^th carcinogen as expressed in units of micrograms per kilogram of body weight per day ( µg/kg-d); and

(2) MHRV_Cn represents the MHRV of the first, second, through the n^th carcinogen as expressed in units of micrograms per kilogram of body weight per day ( µg/kg-d).

B. A cancer index of one is equivalent to a cumulative MHRV. A cancer index greater than one exceeds the cumulative MHRV.

Minn. R. agency 144, ch. 4717, CANCER INDEX AND HAZARD INDEX, pt. 4717.8550

26 SR 1229

Statutory Authority: MS s 144.12