1. Short title This Act may be cited as the Chemical Assessment Improvement Act . 2. Hazard Identification and Dose Response Assessments (a) In general Beginning on the date of the enactment of this Act, any covered assessments carried out with respect to a chemical substance through the Integrated Risk Information System program of the Environmental Protection Agency as of the day before such date of enactment shall, in lieu of being carried out through such program, be carried out by the relevant program office of the Environmental Protection Agency, so long as the relevant program office determines there is a need for such an assessment. Such an assessment shall be carried out using scientific standards specified in section 4 and be based on the weight of the scientific evidence. (b) Toxicity values In carrying out such an assessment with respect to a chemical substance under subsection (a), the relevant program office shall assign a toxicity value or values, when scientifically supported by the available data, for such chemical substance. With respect to that assignment, the following shall apply: (1) When supported by the available data, the toxicity value or values shall include a range of point estimates of risk as well as sources and magnitudes of uncertainty associated with the estimates. (2) When multiple point estimates can be developed, the relevant program office shall— (A) consider all datasets