Sodium Selenite

Sodium Selenite (R1425) is considered a hazardous chemical – it has acute toxicity if inhaled or ingested, and leads to eye and skin irritation if contact occurs.

It’s listed under Hazard Class 6.1, which is the same class as arsenic, cyanide, lead and pesticides.

See the International Programme on Chemical Safety's page for more information.

If we use this ingredient, it needs to be kept essentially quarantined away from everything else.

When moving or using it, everything must be observed and signed off by Quality, and PPE such as filter respirator masks have to be worn.

It’s also quite toxic to the environment so we have to be extremely careful that it is stored and disposed of correctly.

While it is technically an approved form of selenium, the risks are far too high to use it.

The high selenium content is what makes it so toxic – Sodium Selenite is 45% selenium, whereas other forms in Access are 2% at most. This means there is also a risk of the Sodium Selenite not being mixed into powder blends properly – such a small amount gets used (e.g. 25g in an 80kg mix) that it’s hard to verify whether it’s dispersed evenly.

I would recommend R1159 L-Selenomethionine instead – this is selenium bonded to an amino acid so is more readily available. We tend to have this in stock all the time, and it’s much cheaper than the Sodium Selenite.