Is thermalite building blocks harmful to fish?

Thermalite building blocks are generally not considered harmful to fish when used in construction, as they are primarily made from lightweight aggregates and do not leach toxic substances into the water. However, if they are used in aquatic environments or if they contain additives that could potentially leach harmful chemicals, there could be a risk. It's essential to ensure that any materials used in or near water bodies are safe and suitable for aquatic life. Proper assessment and adherence to environmental regulations can help mitigate any potential risks.