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Posted By Topic: Spray Booths

Aug 27 2017 16:31

Hi People.

I recently visited a place that sprays metal housings. They dont do this in a booth, but in a large warehouse.
They have an extract fan (non EXD rated) and leads, lights etc all non EXD rated. I feel that I need to advise them to look at the way they do this, as in general the levels of vapour could be on the limits of a risk.

Q: What defines an activity such as painting that requires, by law, a proper booth?


Aug 27 2017 19:39

It needs a suitable qualified person to define the zones for the tasks been undertaken and from there suitable electrical equipment can be installed

Aug 28 2017 08:20

There's nothing that 3will trigger a particular requirement for a {proper booth"
what matters is whether there is an explosive atmosphere present in "sufficient quantity as to require special precautions" as defined in ESR 4.
That's a yes / no question, but it's also a judgement call.

An answer of "yes" means compliance of electrical stuff with AS/NZS 60079.14 is required [ESR 60], plus inspection of any installation PEW [ESRs 6A & 70], plus regular periodic assessment [ESR 75].

The precaution options will include setting up a booth, but that's by way of cost saving by reducing the area that is subject to all those extra rules and the associated costs; and not a requirement to install a booth.

Aug 28 2017 21:16

We have a whole room inside a purpose built factory with some sort of fire rated walls and doors. The print operators mix powdered ink with solvents at one end of the room and use the resulting liquid inks on screen printing presses at the other end. It contains no particular rating on the equipment (including lots of contactors and heating elements for drying the prints) inside the room. Only thing of note is the 15 amp single phase wall sockets at the mixing end are all wash-down rated.

However, the ventilation (both supply and extraction) is substantial. Supply comes in at both ends and the extraction goes out at multiple levels at the middle of the room. The extraction is such that the air pressure in that room is lower than the rest of the factory.

The building was designed in 1995. I wasn't employed here back then so don't know how much effort went into it.


Aug 29 2017 16:18

Actually there is something that triggers the need for a proper Spray booth or designated spray area and that is the Spray coating regulations 1962.

In general spray coating must be preformed in a booth or designated area , there are some exceptions but they are not extensive .
See below :

Spray coating shall be performed in such a manner and under such conditions as will provide effective protection of the operator and other persons from injurious substances and from other hazards created by the process.

(2) Without prejudice to the generality of subclause (1), spray coating shall be performed in a booth:

provided that—

(a) a booth shall not be required where the process of spray coating is performed in the open air where there is free air movement and the article being spray coated is not less than 6 m from any building or erection:

(b) boilers and heavy articles usually made in boilermaking and engineering works may be spray coated in the workroom in which they are assembled:

(c) complete aircraft or large parts thereof may be spray coated in a hangar:

(d) spray coating of small areas of articles which have been damaged and repaired may be performed in a workroom if the process of spray coating takes place for not more than 10 minutes at a time with an interval of not less than 50 minutes between each application of the substance being sprayed.

Regulation 4(2) proviso paragraph (a): amended, on 29 August 1975, by regulation 2(1) of the Spray Coating Regulations 1962, Amendment No 1 (SR 1975/221).

Aug 29 2017 17:20

Thats very interesting guys. im reading through the lines to say "it's ok". Thanks to The DON, thats some sensible stuff there. Sort of common sense as usual with these undefined things.
my main issue was with leads etc in the spray area, not so much the accumulation of vapour as its a huge building.
I did go to once, a place that spray paints coffins. All exd gear, booths etc, with purge valve timers etc, and the sprayer had a multi box dragged in, door chocked open, and a radio plugged in for music!!

Aug 29 2017 17:38

Thanks, The Don
Perhaps I should have said "nothing in electrical rules"

people keep wanting to "go back to when there was just one simple regs book"; but there never was such a time, there have always been other, non-electrical, regulations etc that we've had to comply with.

Aug 29 2017 17:43

Thats very interesting guys. im reading through the lines to say "it's ok

I wouldn't assume that from what information you originally provided .
There is raft of things that come into play when it comes to spray areas and its not just about the electrical aspect. That said the spray coating for example reg 6 states the following

Where, in accordance with the proviso to subclause (2) of regulation 4, spray coating is performed in any place other than a booth or in accordance with a certificate of exemption issued by the Chief Inspector, the occupier shall:

(a) provide every person engaged in spray coating with such protective clothing, including face masks and respirators, as will afford those persons adequate protection from the substance used in the process:

(b) if any other person is employed or working within 6 m of the spray coating process, so screen the process as to afford adequate protection to that person from the substance used in the process, or provide that person with such protective clothing, including face masks and respirators, as will give him equivalent protection:

(c) cause the air in that place to be changed at a rate equal to not less than 20 times an hour for the period commencing with the beginning of the process and ending 15 minutes after the end of the process:

provided that this provision shall not apply where spray coating is performed in accordance with paragraph (a) of subclause (2) of regulation 4 or in accordance with a certificate of exemption issued by the Chief Inspector.

Regulation 6(b): amended, on 29 August 1975, by regulation 2(1) of the Spray Coating Regulations 1962, Amendment No 1 (SR 1975/221).

So are they complying with that ? from what you described I would suspect not .
Go check out the regs yourself , you will find even more intresting stuff :)( web link attached )
Sadly these regs are pretty old but still law
so in your example it would depend on the size of the bits being painted , the lenght of time painting is taking place etc and of course is the paint flammable.
Once again maybe not enough info to say for sure but from what you described I suspect they should be using a booth .

Aug 29 2017 18:25

I got my inspectors ticket for SHELL OIL and hazardous areas. (BP, MOBIL etc etc). You are quite right in that here are more than electrical considerations involved.
To be honest, most people duck for cover on hazardous areas work, unless it is a gas works, or big player.
Sometimes, common sense rules, and in my case of the spray painters, i'm going to suggest a review of the GEAR they use in the area, and of the requirement to check codes for ventilation.
I would also suggest they look at OSH requirements for the work they do.
im sure there must be standards for the accumulation of vapour (explosive) in the work area. Ill look that up now.

Aug 30 2017 11:06

Hi Again , All it comes down to is what type of paint are they using ? if it not Acrylic then there is most likely a hazardous vapour in the area around the gun when spraying is taking place.The Zonal area around the object being sprayed is defined in AS/NZS60079:10, if you do work for Z etc as you have said then you should be familiar with that standard . You can also find more information in AS/NZS4114.1 and 4114.2

Aug 30 2017 11:26

I wouldn't count on even acrylic paint being non-explosive for spraying. Once fine particles are suspended in air, lots of normally non-flammable stuff can be explosive.

But even if the process & materials used don't create a "hazardous area", and despite any exemptions in the spray-coating Regs; HSW Act & Regs require potentially harmful substances to be adequately controlled to prevent risk.