Without seeing the mapping function I can’t be sure but nothing said so far suggests anything but a linear scaling.
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Did a bit more research. I don’t have access to the Standard or Draft Standard AU/NZS5328 so cannot read what it states, but in the introduction of the Draft Standard for public comment by the Water Services Association of Australia, it gives the following quote:
"DR AS/NZS 5328:2021, Flushable Products is a draft Standard for flushable products. It is currently available for public comment.
The draft Standard sets out a framework, test methods and criteria for determining if products are suitable for disposal by flushing them down a toilet. It also provides guidance and requirements for the labelling of products that are likely to be flushed down the toilet. It excludes toilet paper, liquids and soluble products."
The last sentence may be important: should the Standard be used in a test of toilet paper disintegration by Choice if the Standard apparently excludes toilet paper?
Thanks again.
The new standard, products now have 6 months to comply with labelling requirements.
The solution still relies on householders/consumers observing the requirements to only flush approved products. The greater hope is the standard puts an end to manufacturers make dubious product claims.
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So does the new standard apply to toilet paper? The topic of discussion was the dissolution time of toilet paper, and how that was measured, as in, did a 0% dissolution rating mean that nothing would be dissolved.
It is good to have a standard for all the other things that could go down a toilet, but if the standard does not apply to toilet paper, then why even bring the standard up in this discussion?
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Apparently not.
You are right, it is a bit tangential.
I was pleased to see that hippos are covered. However it seems to have omitted any mention of bats, we have a lot of bats 'round here in the summer.
Alternately.
Of course what is not flushable toilet paper to some is as flushable as toilet paper. Would you like the topic header updated to recognise the broader scope or is the ACCC action appropriate?
Wisdom is to offer a solution.
Where to next?
Should the standard apply to TP?
It seems the new Standard was never intended to apply to toilet paper, so I would leave its scope where it is. But given that, some of the basis for testing the dissolution/disintegration of materials may be worth taking on board for assessing toilet paper.
And I agree with an earlier comment that the rating of 0% dissolution at a time more than 3 minutes, and 100% at the minimum time observed may be improved by just providing dissolution times, however they are determined.
And perhaps a sensitive or crude comment: the toilet paper is not floating around on its own in the flushed water, there are the products of excrement, urine and toilet cleaner (maybe) in the mix. Turbulence, induced or natural, could also be considered to assist with mechanical breakdown in the piping.
I can’t recall where I read it but I think the Choice testing procedure applies a standard amount of agitation to the test apparatus but does not add any other substances. Perhaps @airedale can tell us if I recall correctly.
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Hi @syncretic you’re correct - here’s a video of the testing apparatus, comparing toilet paper dissolution time to the various quote-unquote flushable wipes… (and despite looking like a funky blender take it from me - worst. milkshake. ever.)
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Looks like a pretty straightforward yes/no outcome using these samples.
But back to the various brands/types of toilet paper, what or when is the point where a sample is considered “disintegrated”? Just visual, or something else?
It is passed through a mesh (can’t remember the sizing). Anything that doesn’t pass through is assessed for percentage of the original and this gives it a rating of disintergration.
Testing for wipes as an industry standard is different:
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I had a quick look at the IWSFG Standard (PAS3), and it, like the draft AS/NZS Standard 5328:2021, states clearly that it does not apply to toilet paper. Yes, it is at least something to go on, but for whatever reason the standards do not cover toilet paper. And the IWSFG tests seem to use either a 12.5mm or 25mm diameter sieve or perforated plate, both of which are tiny compared to toilet drains and piping in place pretty much everywhere. Strange. I guess you could extrapolate it up to the size pipes really in use.
There is no need for any extrapolation as any size sieve can be selected, extrapolation is only necessary if direct measurement isn’t possible and that is not the case.
The aim is to find a standard measure of the degree of disintegration not to assess if it will go down a standard household drain pipe. If you made the sieve that size, which is quite possible, it would not discriminate.
The problem is not that it won’t go down a standard pipe but if it doesn’t disintegrate enough it will tend to adhere to any blockage and make the blockage grow, ie make a fatberg. If it is close enough to a slurry it will not do that and keep flowing.
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I have reviewed the standards again, and none say they are applicable to toilet paper, and they don’t seem to involve products in glass containers being blended by a quickly rotating rod with something attached to the bottom of it.
So, from our discussions, we have an idea about where the disintegration %’s came from, not really ideal as we have seen, need them presented as data, I think. We have also discovered that the referenced standards do not apply and really should not be used here, but maybe some bits copied.
What we haven’t worked out yet is “at what point is toilet paper considered disintegrated?” Yes, a slurry is made, but quantifying “disintegrated” is not clear. Is a sieve or perforated plate used, or maybe a subjective visual, or something else?
Has been a great discussion, thanks to all, as we all may know a bit more about TP.
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There is a measure of disintegration speed. It is the time it takes to break down and pass through the selected plate of a specified size.
If you were thinking of measuring the size of all the individual particles that isn’t done and need not be done as all that is required is the upper bound of the size. It either passes through or does not, so the maximum size to pass the test is set by the holes in the plate. It is a judgement call based on what will flow or agglomerate to set the upper bound.
This is like abrasives, you know the grit will go though a specified mess size. So you know the upper bound but not the distribution of all the sizes of the grit in the sample.
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We don’t know if they use a perforated plate or not. They do in the flushability Standards, but those Standards specifically exclude them for use in the flushability of toilet paper. One requires a 30 second “pre-conditioning” period of soaking the stuff to be flushed. And if you used the perforated plate, at what point would you stop the flow-through and measure the weight of material that has not passed through? So stop at 30 seconds, shut down the flow through, gather the material on top of the perforated plate, dry it and then weigh it, comparing it to the weight of toilet paper initially inserted. If it doesn’t meet a standard for dissolution, and we don’t know what that is, then start another test, stop after, let’s say 60 seconds, do the same extraction and drying and weighing, and on you go. This protocol is unwieldy and unlikely.
What is more likely, and maybe Choice people can confirm, is to whack standard measures of toilet paper in a glass container, start agitating, and when it “looks dissolved”, call it good, reporting the time taken.
On blocking of the perforations, I have a fair knowledge of fluid flow in porous media, and fluid dynamics, and it is very likely that 2 or more particles that are smaller than the orifice could collect and block the orifice, thereby being leftover as “not dissolved.” Depends a lot on the pressure differential across the orifice and the flowrate and the material, but it likely happens with what we are talking about.
Have we beat this topic up enough? The correspondents simply do not know how Choice measured dissolution, and their input would be appreciated.
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I don’t care about the details of how conclusions are reached… I reckon any TP that starts to disintegrate as you are actually using it may be great for the environment but its a shocker in daily use.
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At least in Perth ‘flushable wipes’ might not be one of the bigger worries. One possible conclusion is flushable wipes use is reduced and another is there are more creative things being flushed and put in sewers these days.
’ A prosthetic limb, jewellery, mobile phones, children’s toys, tennis balls, clothing and even a whole bed sheet have been pulled out after being flushed.’ (another case of simplistic journalism whereby everything in the sewers must have been ‘flushed’)
No disintegration times posted.
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