This discussion regarding using Borax or Borax substitute, seems to be appearing again on posts so thought I would share my views. Notice I say, my views, I am not trying to tell you what to do before any of you get annoyed!
There is quite a difference between these two items, both of which can be used in frugal laundry detergent.
Borax Substitute (Sodium Sesquicarbonate)
Sodium Sesquicarbonate is included on the INCI list of cosmetic ingredients and is the industry standard builder for traditional bath salt formulations, treating hard water for a relaxing bath.
The product can also be incorporated safely into bath bombs and bath cubes. It is phosphate free and bio-degradable.
How does the above product compare to Borax itself, which seems to be a whole different animal, although you wouldn't think so on some of the sites I've visited this morning.
Borax (Sodium borate, Sodium tetraborate, or Disodium tetraborate)
Borax, whilst being a natural product, is non-biodegradable and can be used effectively as an herbicide and insecticide! Care should be taken whilst using it, as the powder can be toxic if ingested, gets into the eyes or through prolonged exposure on the skin.
None of the above risks mean that you shouldn't use borax, just don't use it around food, keep it out of reach of children and pets, and make sure you rinse borax out of clothes and off surfaces before use.
However, I do feel you need to know (and no on-line places that sell this product seem to mention it), is that Borax was added to the Substance of Very High Concern (SVHC) candidate list on 16 December 2010. Substances and mixtures imported into the EU which contain Borax are now required to be labelled with the warnings "May damage fertility" and "May damage the unborn child". It is for that reason that we can only generally buy Borax substitute in shops. On-line is a whole different ball game and the 'warning' label slapped on the front, is quite frankly, enough to put me off using it all the time.
I think it is really a case of 'you pays your money and makes your choice'!