Minnesota Administrative Rules

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 =

E C1 _ HRV C1

+

E C2 _ HRV C2

+ . +

E Cn _ HRV Cn

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 =

D C1 _ MHRV C1

+

D C2 _ MHRV C2

+ . +

D Cn _ MHRV Cn

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.

Statutory Authority:

MS s 144.12

History:

26 SR 1229

Published Electronically:

May 11, 2009