'Washing soda' and 'caustic soda'?

[luckyeight]

Are these two products the same? I know that caustic soda is sodium hydroxide, so what is washing soda?
In a previous AB question someone recommended washing soda as being useful to clean washing machines. Can I use caustic soda for this purpose too as it was the only thing I could find in the shops!
Any help much appreciated.

[theprof]

No, they are not the same.

Washing soda is Sodium Carbonate. The domestic product is an impure or "technical" grade of sodium carbonate and comes in the form of very large white crystals.

You should be able to find washing soda in most corner shops such as Spar etc. I called in a Co-Op branch on my way home from work last night and it was on the bottom shelf in the household section. Tesco, Asda stock it around the same place. It's sold in boxes of 1Kg which look like small washing powder boxes.

Sodium Hydroxide is extremely caustic and is not something I'd recommend for use in washing machines as it will damage the washing machine because of it's corrosive properties.

[luckyeight]

Thanks so much for your answer. I will keep an eye out for washing soda and use that. Thanks again, theprof.

[winny]

Wilkos do washing soda or soda crystals i think are the same but caustic soda is a big no no it is nasty stuff.

[Peter Pedant]

Yikes !

Certainly not, caustic soda is well caustic, you k now like the blood of the alien in ALien

keep awayt from it !