US EPA

In April 2018, EPA released the draft IRIS Assessment Plan for Ammonia and Ammonium Salts Noncancer Oral. An IRIS Assessment Plan (IAP) communicates to the public the plan for assessing each individual chemical and includes summary information on the IRIS Program’s scoping and initial problem formulation; objectives and specific aims for the assessment; the PECO (Populations, Exposures, Comparators, and Outcomes) criteria that outlines the evidence considered most pertinent to the assessment; and identification of key areas of scientific complexity. The PECO provides the framework for developing literature search strategies and inclusion/exclusion criteria, particularly with respect to evidence stream (i.e., human, animal, mechanistic), exposure measures and outcome measures.

Ammonia occurs naturally in air, soil, and water. Ammonia is also produced by humans and other animals as part of normal biological processes. Ammonia is used as an agricultural fertilizer and in many cleaning products. Exposure to ammonia occurs primarily through breathing air containing ammonia gas, and may also occur via diet, drinking water, or direct skin contact.

The IAP communicates to the public the plan for assessing each individual chemical and includes summary information on the IRIS Program’s scoping and initial problem formulation, objectives and specific aims for the assessment, and a PECO framework that outlines the evidence considered most pertinent to the assessment; and identification of key areas of scientific complexity.

U.S. EPA. IRIS Assessment Plan for Ammonia and Ammonium Salts Noncancer Oral (Scoping and Problem Formulation Materials, Suspended). U.S. Environmental Protection Agency, Washington, DC, EPA/635/R-18/041, 2018.