Hello All

1st post and new IOSH Member here. I have recently taken my 1st full time Health and Safety role at a new company. I have been assessment, amending and improving a huge amount of areas but I have one issue that Im slightly struggling with.

Before I started (before the company had a full time H&S advisor) we had a new off site test facility built. Since joining I have been up to the site and conducted an initial Risk Assessment before the site is handed over to operations.

The site is away from out "main site" about 1.5miles away. There is to be various testing going on. Quite a bit to do with large magnetic fields. There is also an area (seperate hut) where we have a large water bath, The bath is about 500mm above the gound but about 2M deep. There is going to be some lone working on the site (not in the water tub area as I have been incredibly insistant that there is not to be no lone working in this hut).

My question is, has any one had any experience with lone working deivces and magnetic fields?

Im looking into a comapny that provides a mobile app for lone working which might work but curious for other opinions and experiences.

Any advice would be much appreciated.

Have you ascertained there are no "not spots" for communications e.g. due to steel construction behaving like farraday cages blocking signals?

That these large magnetic fields themselves will not create issues with standard communication devices?

Hi inzsel

Welcome to the Forums and to IOSH.

I think you need technical advice on the viability of lone working devices for the reasons that Roundtuit sets out and not just the word of some company promising that their kit will work!

However, I also think you need to consider what risks a lone worker would face in this offsite location and to be honest I am a bit puzzled as to why you have specifically targeted NOT allowing lone working in a hut that contains a water bath......

.....as I wonder whether banning lone working is being used as a substitute for effective precautions to prevent someone falling into the bath AND a way of getting back out.

Of course, what you have described may well not be the full story, but as presented in your thread I envisage a hole in the ground potentially full of water with an upstand of 500mm above the surface on which a worker would be standing.

My immediate question would be why is that upstand (or equivalent) a MINIMUM of 1100mm?

It's not as if this bath is similar to a natural feature of the landscape, such as a lake, nor an artificial structure that looks similar to a natural feature, e.g. a reservoir - it's indoors!

....and it's presumably not a swimming pool!

In the scenario of the lake, reservoir or swimming pool there is plenty of guidance as to appropriate safety precautions. 

Which failing my immediate instinct is to go back to tried and tested standards reflected in legislative requirements dating back to e.g. Factories Act 1961 Sections 28 "Floors, passages and stairs") and 29 ("Safe means of access and safe place of employment") and Regulation 24 ("Prevention of Drowning") of the Construction (General Provisions) Regulations 1961.

You don't need to go and read this legislation which has been consolidated into current requirements including e.g. in the Workplace (HSW) Regs 1992 and Work at Height Regulations 2005. 

The great improvement with the newer legislation was that the opporutnity was taken to ditch the old "2m rule", in favour of requiring reasonably practicable precautions whatever the potential fall distance.

[I have personally investigated three fatal accidents involving falls of less than 2m].

I should also be a bit surprised [though to be honest I'm not] that this new facility has managed to get through "CDM" design and construction and end up with such a poorly protected edge, but perhaps the Designers and others made out that the bath was "plant" and not a "structure" - and the bath would probably have got past Building Control for similar reasons.

Unless there is a very cogent reason for NOT providing effective edge protection around this bath, I think you might start with putting that in place and THEN considering the lone working risks of the bath alongside the line working risks of working anywhere else on this off site location,  i.e. such that the bath is no longer to be treated as a special case before a risk assesssment is even started.

Edited by user 01 July 2025 13:35:52(UTC)  | Reason: Tweak

Thank you for the replies.

So it is a test facility. The bath is not for humans but for underwater testing. I have enforced no lone working to ensure we can have a way of rescue incase someone falls in as items do need to be lowered into the water.

the magnetic field will be a various ranges.

I have a demo meeting planned with the same app company as what has been mentioned. they do seem quite good and maybe hit all lone working problems. obviously not fully known without future testing though. It could also help with all other lone working thats within the company.