An ALDI shopper has issued a warning after noticing this important fact about a popular cleaning buy.

Mum Anne shared the detail on Facebook, as she spotted the detail while reading the fine print on ALDI's Di San Pre Wash Stain Remover.

The $1.25 product has a cult following as many use it to transform oven doors, jewellery and shower screens.

But Anne has warned others to be careful when cleaning with the product after noticing that Di San’s back label reads “Do not mix with other chemicals”.

“Warning, don’t mix Di San with other chemicals,” wrote Anne on the Aldi Mums page.

“I used this mix to clean grout on floor. Yes it worked.

“But this mix of Di San and Mould Away gave me headaches and nausea and I did think about checking the labels!”

She gave the warning as many use it to clean the grout on their tiles as they've combined it with other products, such as anti-mould spray.

“Thanks for highlighting this,” said one. “It is so important to read labels. Ventilation is paramount too.”

“Thanks for sharing and warning other members, I didn’t know either,” said another.

Said a third: “A good general rule for all chemicals.”