Updated 1st September 2020

Several weeks ago we issued guidance to help Early Years and Primary as well as secondary school Science and Technology departments prepare and be as ready as they can be to keep learners and all others safe now schools are back. The new guidance from the Scottish Government has rendered much of our original guidance on distancing obsolete. But the advice on hygiene and much of the advice about adapting practical work is still relevant.

We will address further issues by means of an FAQ section. (In the document but also replicated at the bottom of this page.)

The documents can be downloaded from the following links

Early Years & Primary

Secondary science and technology

We realise that there will be wide variation between schools across the country in terms of: pupil rolls, number and size of classrooms, etc. The advice here is necessarily general. If you have specific advice, please contact us at SSERC.

For guidance on other aspects of returning to school, you should consult the advice from the Scottish Government which can be found here (https://www.gov.scot/publications/coronavirus-covid-19-guidance-preparing-start-new-school-term-august-2020/)

These (above) are versions 2.0 of the Early Years and Primary guidance and 3.o of the secondary guidance. Future additions, will be in the form of FAQs added at the end of the documents.

Frequently Asked Questions

New FAQs will be added at the top of this list 

Are alcohol-based sanitisers permitted in laboratories?

We have heard suggestions that alcohol-based sanitisers should not ever be used in science labs because of their flammability.  We disagree.

As long as they are not used next to a source of ignition and time is allowed for the alcohol to evaporate from hands, we think the risk is not significant. Experiments at SSERC with alcohol-based gel soaked into paper tissue showed that it was very difficult to get it to light without it being extremely close to the flame. Caution should be observed but, used sensibly, we see no significant risk. Once the stock has been exhausted, it would perhaps be prudent to make the next purchase an alcohol-free formula but there is no reason to withdraw your current stock from use.

Regarding alcohol -free formulations – there are now several on the market that seem to be active against coronaviruses: mostly ones based on quaternary ammonium compounds. When assessing the overall risk, it is worth bearing in mind that though these are not flammable, research suggests they need at least two minutes on the hand to provide the same level of protection you get from alcohol gels in 20-30 seconds.

Disinfectant concentration

There have been numerous questions about this:


Milton have changed their guidance on dilution when their products are being used for disinfecting Covid-19. Rather than the general figures stated on the packet/bottle, you would use the following.

  • Fluid: 60ml fluid per litre of cold water
  • Tablets: 2 tablets per litre of cold water.

Milton on their website suggest a contact time of 15 minutes.


The WHO recommends a 1:100 dilution of bleach that is 5%. Research published in the Lancet Microbe suggest that this concentration will ‘kill’ the virus in under 5 minutes. (The revised figures for Milton’s fluid, which is chemically similar, are about this concentration as well) However, it seems that many bleaches sold in the UK are a lower concentration, 1-1.5%.

So in order to get to the 0.05% dilution that is suitable you will need to dilute as follows

  • 1 part 5% bleach + 99 parts cold water* OR
  • 1 part 1% bleach + 19 parts cold water
  • (for other concentrations, calculate as appropriate)

Contact time

Milton suggest 15 minutes for their product but the lancet paper suggests that a similar dilution of bleach will be effective in under 5. If there is time, it is probably prudent to leave for 15 but the evidence suggests that a shorter exposure will not be a problem.

Thick v Thin bleaches

There is no difference in effectiveness as far as the ingredients are concerned but the thick bleaches tend to be higher in sodium Hypochlorite.

  • Thin Bleach £0.19 per litre (Tesco) – 1%
  • Thick Bleach £0.52 per litre (Tesco) – 4.6%

* To be absolutely certain of having the right level of available chlorine, you should dilute a 4.5% bleach 1+89 rather than 1+99 but given that this will be a concentration of 0.046% rather than 0.05, very close, then leaving it for, say, 10 minutes rather than 5 should guarantee effectiveness.

Thick bleach has various additives, the main function of which is to help it stick to vertical surfaces like lavatory pans, for long enough to be effective This is not relevant for our purposes.

The thick bleach will work out more economical but be careful diluting it – as it contains surfactants, it is best to add the bleach to the water and stir gently rather than the other way round – that will result in less foam being produced.


  • Do not mix bleach (or Milton’s) with other products as toxic chlorine can be produced.
  • Be careful of using these, or any other chlorine-based disinfectants on coloured items, especially cloth as it can get bleached.
  • Bleach can also corrode metals, even stainless steel over time so be careful with any metal items.


Both Miltons and bleach at these concentrations are dilute enough that they can simply be washed to waste.


Current guidance is to make a fresh solution of either bleach or Miltons each day. We are currently looking to see if there is a simple way of testing your soaking bath to see if this is needed. Until and unless we do, then you will need to replace the solutuions on a daily basis.

How can we manage to sanitise eye protection? A full disinfection between each use would be incredibly difficult and time-consuming.

There are two approaches to be taken here: try to reduce sharing and try to sanitise where possible.

More details on ways you can keep your eye protection sanitised can be found in a separate document here: https://www.sserc.org.uk/wp-content/uploads/2020/08/Disinfecting-Eye-Protection.docx

Lab Coats and Microbiology

In the first version(s) of this guidance, we overlooked that, unlike in many areas, lab coats are a requirement for carrying out microbiology.

If each learner has their own lab coat, this is not a problem: no extra laundry is required.

If they need to be shared then procedures need to be put in place for disinfection. The virus does not survive for as long on fabric as on hard surfaces so leaving them for 24h before being used by a second individual should be fine. One issue is that of buttons or other fastenings of metal and plastic. The virus can last longer on these so they should be sprayed with ethanol, Milton’s/dilute bleach, hydrogen peroxide or a commercial antiviral product. (or they could be wiped but that will be more time consuming). Alternatively, the coat can simply be left for 72h between uses.

In Technology departments, most (if not all) schools have each workshop arranged with 5 work benches, each with 4 vices. 4 pupils are seated at each bench facing each other. Your guidance states that pupils should not face each other: what do we do?

In the guidance we say it is “important to arrange as far as possible that learners are not seated across from each other but side by side.”

There are many situations where tables and/or seating can be moved to facilitate this. Clearly though, in the situation described, it isn’t possible so you just carry on as normal – in that way at least.

The seating arrangement is just one approach: enhanced, sanitising, restrictions of students moving round, fixed groups if possible, keeping distances where possible etc will all contribute, along with the seating arrangements. So just do what you can, and don’t worry too much about what you can’t do. It is, after all, guidance, not instruction from the Government.

Most of the schools in our area have been issued with huge quantities of hand sanitiser – 1750 litres in my school! What are your recommendations for where we should be storing this?

We are currently (7the August) investigating further but unless there has been an exemption put in place (possible but we are not aware of one) then if the hand sanitiser is alcohol based then it is a flammable liquid and thus, under the requirements of DSEAR, need to be stored as such. These quantities obviously create probelms for a school.

A better option would be for the council to see about storing it centrally – as they will be able to find suitable storage more easily – and send it out in smaller quantities.

Even so, there will still need to be suitable storage on site. So either a room will need to be converted to a flammable store (possible a little used toilet could be adapted as it already has ventilation) or one or more flammable cabinets will need to be purchased and positioned in a suitable place. The details will depend on how much is stored on the premises at any one time.

This is, however, like all Health and Safety issues, a matter for the employer. So the school should contact ther Local Authority and raise the issue with them.