Question 1

How much nitrite is lethal?

Accepted Answer

Published figures for an adult swallowing pure sodium nitrite range from about 0.7 g to 6 g; a drug-safety datasheet gives about 1 g as the average lethal dose without treatment, and a forensic review estimates about 2.6 g. People react differently and treatment changes the outcome, so there is no sharp line.In curing salt that means: 1 g of sodium nitrite is in about 16 g of Cure #1 — the amount you would weigh for six or seven kilos of meat. In European nitrite salt at 0.6%, the same 1 g is in about 170 g of salt, which is why that weaker mix is what shops in Europe sell.

Question 2

What does nitrite poisoning look like?

Accepted Answer

Nitrite turns haemoglobin into methaemoglobin, which cannot carry oxygen. Signs come within minutes to a few hours: bluish lips and fingertips, headache, dizziness, breathlessness, a racing heart, nausea; then confusion and loss of consciousness. There is an antidote (methylene blue), but it has to be given in hospital. If anyone may have swallowed curing salt, call emergency services immediately — do not wait for symptoms.Accidental cases are usually mix-ups: curing salt or pure nitrite used as table salt or sugar in cooking.

Question 3

What dose goes into the meat?

Accepted Answer

Doses in meat are counted in ppm — milligrams per kilogram. The usual dose is 156 ppm: 156 mg of sodium nitrite per kilo of meat, which is about 2.5 g of Cure #1 (0.25% of the meat’s weight). US limits for meat plants are 120 ppm for bacon in brine, 200 ppm for dry-cured bacon, 156 ppm for ground meat, and 625 ppm going into a dry-cured whole piece with no more than 200 ppm left in the finished product. Part of the nitrite breaks down during curing and cooking, so the finished product contains less than went in; how much less depends on the product.

Question 4

Then what dose is acceptable to eat?

Accepted Answer

The European Food Safety Authority set the acceptable daily intake at 0.07 mg of nitrite per kilo of body weight per day (EFSA, 2017; the international expert committee JECFA uses the same figure). For a 70 kg adult that is about 5 mg of nitrite, or about 7 mg of sodium nitrite, every day for a lifetime. It is a long-term average, not a toxic threshold: going over it once is not poisoning. EFSA found that nitrite added to food keeps most people under this level, with a slight excess only in the most exposed children.

Question 5

What about cancer?

Accepted Answer

Two separate findings by the WHO cancer agency (IARC):Processed meat — cured, salted, smoked or with added nitrite — is classed as carcinogenic to humans (Group 1), mainly for bowel cancer. That is about eating it regularly over years, not about one ham sandwich.Nitrite eaten under conditions that lead to nitrosamines forming in the body is classed as probably carcinogenic (Group 2A). Nitrosamines form from nitrite and protein breakdown products, faster with high heat — frying bacon crisp — and more slowly when vitamin C is present. That is why US rules require 550 ppm of sodium ascorbate or erythorbate in injected bacon.The practical side for a home cook: weigh the dose, do not go over the recommended amount — above it there is no extra protection, only more nitrite — and do not burn bacon.

Question 6

Is it more dangerous for children?

Accepted Answer

Yes. Babies are more sensitive to methaemoglobin, and EFSA found that the most exposed children are the only group that slightly exceeds the acceptable intake from food additives. Keep curing salt out of reach, and do not give cured meat to infants.

Is curing salt dangerous? Which doses are toxic?