Nitrate

Overview

In November 2023, EPA released the Protocol for the Nitrate and Nitrite IRIS Assessment (Oral) (Preliminary Assessment Materials) for a 30-day public review and comment period. As part of developing a draft IRIS assessment, EPA presents a protocol that describes the methodology for how the assessment will be conducted, including systematic review and dose-response. These could include strategies for literature searches, criteria for study inclusion or exclusion, considerations for evaluating study methods, information management for extracting data, approaches for synthesis within and across lines of evidence, and methods for derivation of toxicity values.

Background

Nitrate (NO3−) and nitrite (NO2−), naturally occurring anions in the environment, play an essential role in Earth’s nitrogen cycle. Since 1950, human sources of nitrogen have increased substantially, creating a global surplus of nitrate/nitrite that supersedes natural sources by about 30%. Nitrate salts are mainly used as nitrogen fertilizers and in industrial explosives, fireworks, and glass making, whereas nitrites are largely used as preservatives for meat and fish curing and as color fixatives.

History/Chronology

Date	Description
Sep 2017	EPA released the IRIS Assessment Plan (IAP) for Nitrate and Nitrite for public comment and review. [Federal Register Notice Sep 18, 2017]
Sep 2017	EPA's Science Advisory Board (SAB) Chemical Assessment Advisory Committee (CAAC) hosted a public meeting on September 27-28, 2017 to discuss the assessment. Information regarding the meeting can be found on the SAB website.
Apr 2019	EPA suspended the assessment in fiscal year 2019. It may be restarted as Agency priorities change.
Jun 2023	The assessment was unsuspended and announced in the June 2023 Outlook.
Nov 2023	EPA released the Protocol for the Nitrates and Nitrites IRIS Assessment (Preliminary Assessment Materials). The deadline for comments is December 11, 2023. [Federal Register Notice Nov 9, 2023]

Status

The IRIS Program will use the protocol to develop the draft assessment.

This download(s) is distributed solely for the purpose of pre-dissemination peer review under applicable information quality guidelines. It has not been formally disseminated by EPA. It does not represent and should not be construed to represent any Agency determination or policy.

• Protocol for the Nitrate and Nitrite IRIS Assessment (Oral) (Preliminary Assessment Materials) (PDF)  (151  pp, 2.2 MB, about PDF)

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Document Related Link(s)

• IRIS Assessment Plan for Nitrate and Nitrite (Scoping and Problem Formulation Materials, 2017)

HERO Project

• Literature Search References Sorted by Author (Nitrates and Nitrites)

Federal Register Notices

• FR Notice: Nov 9, 2023

Docket

Comments on the assessment may be submitted and reviewed using the Docket ID EPA-HQ-ORD-2017-0496