Why is melamine not considered safe to use in the microwave? Melamine is an insulator and not a conductor of heat or cold. This means that when melamine is heated in the microwave, it will stay hotter longer than the food in most circumstances. The chemical properties of melamine promote thermal insulation and have low opportunities for transferring thermal energy. Insulation is an excellent quality to have in a buffet or cafeteria cold well, but it is not ideal when reheating food items.
The chemical properties of melamine allow temperatures as cold as -22 degrees Fahrenheit and as hot as 185 degrees Fahrenheit without breakage. According to the FDA website, melamine will not migrate or transfer into food unless it is heated above 180 degrees Fahrenheit. Melamine is known for its low acute toxicity and is not classifiable according to its carcinogenicity in humans. The FDA has concluded that under normal use conditions, melamine migration can be 10 parts per billion parts of the food item, which is well below the risk level.
Another reason behind melamine’s microwave restrictions stems from the degradation of the product when exposed to high heat for extended periods of time. Due to the material properties of melamine, the wood pulp being the base component, it is not recommended for use in the microwave. Wood pulp is porous, and the moisture content greatly affects the durability of each piece. When melamine is repeatedly exposed to temperatures above 185 degrees Fahrenheit, the pieces dry out and begin to weaken, which correlates to shorter service life.
Microwaves, heat lamps, and convection ovens are all extremely damaging to melamine long term and typically will void your warranty. Normal wear and tear can be kept low by maintaining enough stock to keep the recommended three dinnerware sets per daily guest count. This 3-to-1 rule keeps your guests from having to use wet plates or bowls and allows the pieces proper time for cleaning between use. If all manufacturer recommendations are followed closely, your replacement rate should only be 10%-20% of your melamine annually.