• Question: What is the most dangerous chemical you have ever worked an how did you handle it.

    Asked by edge134raw to Caroline on 23 Jun 2021.
    • Photo: Caroline Roche

      Caroline Roche answered on 23 Jun 2021:

      The most dangerous one was Hydrofluoric acid (HF). It started out as a gas and then was cooled to be a liquid.

      I worked along side the process engineers who have designed the chemical process to make sure no one could use the control system to do something dangerous.
      The system monitored the hardware (Valves, pumps) to make sure they were all working correctly before they could be used and monitored levels in tanks so if we transferred 100 litres but only 80 litres arrived, then the system would flag a leak.

      The control systems are always tested multiple times, first at my office to make sure the software worked and would work safely.
      Then when it was installed at site, it was tested again just with the equipment to prove the hardware and software worked together.
      Then we would test it using an inert gas and liquid (usually water) before slowly starting up the process and working with the chemicals.

Comments

  • Photo: Katie

    Katie commented on :

    The most dangerous chemical I work with is called Hydrofluoric acid (HF). This is a liquid, which we use to etch through glass. It’s dangerous because if it gets spilled onto you, it can attack your bones and you could end up with very serious injuries. Everyone is really careful when using this though, and I’ve never known of an accident in any of the labs I’ve worked in.

    To handle HF safely, we must be properly trained in our lab. We have a special antidote gel, ready for an accident. We also have an emergency shower which we must use to wash away any spills onto someone as soon as possible. These are as a last line of defence though, and we have to wear lots of PPE which using HF. We wear a safety apron to cover our body, thick acid-proof gloves which go up to our elbows, and a face visor. We also only use the HF inside a designated fume cabinet, which keeps the risk of it splashing onto our PPE very low.
    We also only use designated beakers for this work, so there is no contamination. The HF is also stored in a locked cabinet, so only trained users can get it.

  • Photo: Louise

    Louise commented on :

    There is a factory near us which makes rocket fuel. They have all sorts of dangerous chemicals, mainly Hypergolic propellants (rocket engine fuel). It’s so dangerous that only small amounts of the chemicals are kept. They are kept in individual brick built buildings, each chemical has its own building. They are highly volatile, flammable and explosive. Each factory has decent distance so that if an explosion was to happen, it will be contained to that building and not result in other buildings exploding. We had to provide the ventilation. We had to supply a system which is suitable for the fire and explosion risk. We had to source a centrifugal fan with anti-sparking features because otherwise the fan could be a source of ignition which could result in explosion. The fan impeller had to be made of brass. Motor was positioned outside and we used belts from the motor to turn the impeller. Friction of the air inside our ventilation system could result in static, static is a source of ignition too. So to prevent this, we earth our ductwork. We connected the green and yellow earth wire to several points of the ductwork and fan. This is then connected to the earthing boss for that buildings electricity. We had issues with some chemicals being very corrosive so we could only use PVC plastic parts on some systems.

  • Photo: Hannah

    Hannah commented on :

    I have used hydrochloric acid, sodium hydroxide (caustic) and sodium hypochlorite (bleach). THese were used as cleaning chemicals in the water treatment plant. We had to wear a chemical suit and respirator to handle these. Sometimes we would use sodium hypochlorite to clean the floors, and it was also used as part of the process to disinfect the water and make it clean.
    In any area where you might expect to be working near chemicals like this, there is a ‘safety shower’ that you can very quickly operate in an emergency to help wash the chemical off you, and lots of materials for stopping spills or for use as extra PPE if you need it