Food-Safety – Reasons to Use Gloves When Handling Food

Ammonia (generally ammonium salts) is found in most naturally occurring foods, as is a product of growth and decay

Ammonia gas is used in some food processing line machines to ensure cleanliness of the machines and the food passing through it. The naturally occurring level of Ammonia in many foods is in the 10 or 100's of ppm, so the trace amounts left behind from the processing line would not be noticeable in most cases

Ammonia dissolved in water (Ammonium Hydroxide) is used in some food processing plants (ice makers, milk and beer bottling etc) to clean the rooms, machines, and handling equipment. There will always be trace amounts left over from this process but it should be below 1 ppm

Salamis and fatty cheeses often have the Ammonia level around 1000 ppm; these sorts of foods are often labelled by government food agencies as a "sometimes" food

Some wild game meats may also have Ammonia levels around 1000 ppm, this is one of the reasons some people cannot eat game meats (taste/smell)

Some cultures use Ammonia salts in their food. e.g Ammonium Carbonate as a heat activated raising agent (Greece, Germany etc.), or Ammonium Chloride in salty liquorice (Netherlands, Nordic, Baltic areas etc.). But that is not really adding Ammonia, just adding a salt of it

The recommendations (in the US at least) are based on a risk model, which takes into account a number of factors:

• frequency of outbreaks and occurrence of illnesses
• severity of illness, taking into account illness duration, hospitalization and mortality
• likelihood of contamination
• growth potential/shelf life
• manufacturing process contamination probability/intervention
• consumption
• economic impact

Some of these factors are statistical (frequency, economic, for example), and some are measured (growth, aspects of severity). For the measured aspects, a large number of methods are employed, including animal testing, human histories, and toxicology reports (including LD measures).

Primarily, most home cooks should follow the FDA guidelines as the recommendations take into account the supply chain and common outcomes for most pathogens (for a given food). It's important to note that live pathogens are not the only risk in food safety, also toxins (as produced by the pathogens) are an important factor depending on the specific life form. These toxins are not mitigated by cooking (generally), and some pathogens are not completely mitigated by heat or cold. The risk is related to the combined risks, time, and supply chain.

The FDA site contains the regulations, methods, and sampling guidelines for various stages of food production and food safety.

This is not my speciality, but I did teach food safety many years ago (please refer to the current guidelines and methods for current recommendations).

References:

1. Designating high risk foods
2. Home food safety cheatsheet
3. Example toxicity studies - I'm not certain these feed into these specific guidelines, but the methodology will be similar