With the recent spate of acid attacks becoming a very real threat in London, it would be prudent to try and protect yourself in whatever way you can. If you work with hydrofluoric acid, you should be well aware of the risks posed by it. If you are not, you need to familiarise yourself — and quickly. Despite its resemblance to water visually (both are colourless liquids) the two couldn’t be more diametrically opposed when it comes to risk to human health. As a corrosive acid, hydrofluoric acid is dangerous in all guises and a great deal of care and caution is required to handle it safely.
What are the consequences of contact with hydrofluoric acid?
Exposure to a high dose of hydrofluoric acid for a period of just five minutes can be fatal. Because of its corrosive properties, contact between hydrofluoric acid and the skin can cause deceptively deep-seated burns. Depending on the concentration of the solution used, the victim may not even be aware of the injuries they have sustained until hours later. When the hydrofluoric acid dissociates, fluoride ions cause the destruction of soft tissues and decalcification of the bones, way beneath the affected area of skin.
The eyes are of particular concern, as exposure to hydrofluoric acid in its liquid or gaseous state can, at worst, cause blindness, and at best, mere irritation.
Personal Protective Equipment
So how can you limit the threat posed by hydrofluoric acid before you even begin working with it? The first preventative measure you should take is to ensure you are kitted out in protective equipment. If you had any doubt over the gravity of the risk posed by hydrofluoric acid up to this point, the extent of the Personal Protective Equipment required to handle it is as clear an indication as any of the potential perils.
To protect the eyes, chemical goggles that incorporate a face shield are recommended. To protect the skin, neoprene or nitrile gloves and an acid resistant suit or apron are recommended — a fastened lab coat is considered the bare minimum.
Safety and handling procedures
It almost goes without saying that all work with hydrofluoric acid should be conducted within the confines of a fume cupboard. An operational safety shower should also reside within reasonable distance of where hydrofluoric acid is in use and be easily accessible.
Personnel who are trained in first aid in close proximity
At least one other person, who is privy to the dangers associated with hydrofluoric acid and is capable of providing specific assistance, needs to be present while work with hydrofluoric acid is carried out.
Medical supplies need to be available at all times
Any surfaces that are inadvertently contaminated with hydrofluoric acid should be absorbed, and then neutralised using calcium carbonate or calcium hydroxide.
Exposure to hydrofluoric acid: what next?
The affected area of skin should be positioned under a source of cool running water for a minimum of five minutes before further action is taken. While this takes place, the emergency services should be called and a Material Safety Data Sheet should be acquired ready to pass over to them upon their arrival. All clothes, jewellery and shoes (anything that could have come into contact with hydrofluoric acid) should be removed. Then, 2.5% calcium gluconate gel should be (self-administered if possible) and massaged into the affected area.
If the eyes are affected, they should be flushed out for five minutes with cool, running water. Medical personnel may apply sterile 1% calcium gluconate solution to the victim’s eyes after they have been irrigated.