Risk assessment of nitrate and nitrite in feed

Nitrate, Nitrite, methaemoglobin, occurrence, exposure, feed, animals
First published in the EFSA Journal
4 novembre 2020
Adopted
24 settembre 2020
Type
Scientific Opinion

Abstract

The European Commission asked EFSA for a scientific opinion on the risks to animal health related to nitrite and nitrate in feed. For nitrate ion, the EFSA Panel on Contaminants in the Food Chain (CONTAM Panel) identified a BMDL10 of 64 mg nitrate/kg body weight (bw) per day for adult cattle, based on methaemoglobin (MetHb) levels in animal's blood that would not induce clinical signs of hypoxia. The BMDL10 is applicable to all bovines, except for pregnant cows in which reproductive effects were not clearly associated with MetHb formation. Since the data available suggested that ovines and caprines are not more sensitive than bovines, the BMDL10 could also be applied to these species. Highest mean exposure estimates of 53 and 60 mg nitrate/kg bw per day in grass silage‐based diets for beef cattle and fattening goats, respectively, may raise a health concern for ruminants when compared with the BMDL10 of 64 mg nitrate/kg bw per day. The concern may be higher because other forages might contain higher levels of nitrate. Highest mean exposure estimates of 2.0 mg nitrate/kg bw per day in pigs’ feeds indicate a low risk for adverse health effects, when compared with an identified no observed adverse effect level (NOAEL) of 410 mg nitrate/kg bw per day, although the levels of exposure might be underestimated due to the absence of data on certain key ingredients in the diets of this species. Due to the limitations of the data available, the CONTAM Panel could not characterise the health risk in species other than ruminants and pigs from nitrate and in all livestock and companion animals from nitrite. Based on a limited data set, both the transfer of nitrate and nitrite from feed to food products of animal origin and the nitrate‐ and nitrite‐mediated formation of N‐nitrosamines and their transfer into these products are likely to be negligible.

This publication is linked to the following EFSA Supporting Publications article: http://onlinelibrary.wiley.com/doi/10.2903/sp.efsa.2020.EN-1941/full

Panel members at the time of adoption

Margherita Bignami, Laurent Bodin, James Kevin Chipman, Jesús del Mazo, Bettina Grasl‐Kraupp, Christer Hogstrand, Laurentius (Ron) Hoogenboom, Jean‐Charles Leblanc, Carlo Stefano Nebbia, Elsa Nielsen, Evangelia Ntzani, Annette Petersen, Salomon Sand, Dieter Schrenk, Tanja Schwerdtle, Christiane Vleminckx and Heather Wallace.
Panel on Contaminants in the Food Chain
Contact
contam [at] efsa.europa.eu
doi
10.2903/j.efsa.2020.6290
EFSA Journal 2020;18(11):6290
Question Number
On request from
European Commission