What chemicals react with aluminum foil?

We frequently use aluminum foil or aluminum foil containers. Please note that certain substances should not come into contact with aluminum foil. The surface of aluminum foil contains active metallic aluminum and a dense protective film of aluminum oxide (Al₂O₃), which can react with acids, alkalis, and other specific reagents.

Therefore, aluminum foil containers are not suitable for storing acidic, alkaline, or high-salt foods and chemicals, because aluminum is an amphoteric metal, and the aluminum oxide film on its surface and the aluminum metal itself are prone to react with these substances, causing the container to corrode and potentially releasing harmful substances.

I. Types of Substances That Should Not Be Stored

1. Acidic Substances Common Examples:

Vinegar, plum juice, lemon juice, ketchup, carbonated drinks, etc. Reason: Weak acids such as acetic acid can react with aluminum to produce aluminum acetate and hydrogen gas. This not only corrodes the container but may also cause aluminum to dissolve, which is detrimental to health with long-term ingestion. Reaction Formula: 2Al + 6CH₃COOH → 2Al(CH₃COO)₃ + 3H₂↑.

2. Alkaline Substances Common Examples:

Alkaline solutions (such as sodium hydroxide solutions used for cleaning), concentrated baking soda solutions, certain cleaning agents. Reason: Aluminum and its oxide film can react with strong alkalis to produce aluminates and hydrogen gas, damaging the container structure. Reaction formula: 2Al + 2NaOH + 6H₂O → 2Na[Al(OH)₄] + 3H₂↑

3. High-salt foods Common examples:

Pickled foods (such as salted vegetables, cured meat), braised foods, sauces, etc. Reason: Chloride ions in salt (NaCl) solutions can damage the oxide film on the aluminum surface, accelerating the corrosion process and increasing the risk of aluminum migration.

4. Solutions containing heavy metal ions Common examples:

Laboratory reagents such as copper sulfate and silver nitrate. Reason: Aluminum will displace metals such as copper and silver, while simultaneously being oxidized. The reaction is vigorous and may be accompanied by the release of hydrogen gas.

II. Recommended Safe Alternatives Short-term Refrigeration for above substances:

Use glass food storage containers or food-grade plastic airtight containers. Baking/Heating: If food needs to be wrapped in aluminum foil, avoid direct contact with acidic ingredients (such as lemons and tomatoes), and first isolate it with parchment paper. 

Shanghai Mengjiang Aluminum has specialized in producing aluminum foil(jumbo roll and small roll) for 18 years. Pls feel free to contact us for any questions via email: inquiry@cnaluminiumfoil.com or wechat/whats'app: 8613661547963.