Acceptable Error for Weights & Measures

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sleemanj

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#137984 16-Dec-2013 00:13

Does anybody know what the acceptable error would be for weights and measures in selling goods?

I have here a box of Tasti Mega Nuts Double Choc "6x Big 40g Bars", well, there were 6 but one got eaten already.

Anyway, I happened to grab one out of the box and thought "you know, I wonder, do these weigh 40g".

I have a set of precision digital scales for weighing leds and such (easier to weigh than count), so I took one and weighed it. And another. And another...

33.39g
35.77g
31.98g
32.92g
32.05g

Average weight of those 5 bars left in the pack, 33.22g, 17% less than advertised.

And that's Gross including the plastic wrap, which clearly has printed on it "40g Net".

So I thought, it seems unlikely but maybe my scales are up the wop. I checked on the kitchen (spring dial) scales by weighing the bars all together, about the same result, very under weight.

To compare with another product, I took a "Mother Earth Baked Oaty Slices" bar from it's box, it's also supposed to be 40g, and weighed it on my precision scales, 42g, indeed, it's noticeably heavier than the "40g" Tasti bar, by a lot more than 2g.

I'm seriously thinking that this should probably be forwarded onto whoever is the appropriate authority, surely a product being 17% less than the weight on the packet can't be within accepted tolerances, can it? I imagine if I just wrote to Tasti then they'd probably just put it in the round-filing-bin.

I guess it could be an isolated incident (although it they make being "Big 40g Bars" a big selling point you'd think they'd take more care), perhaps some other readers here have some Tasti snack bars and scales handy? Chime in with your findings!

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James Sleeman
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#952843 16-Dec-2013 06:25

Definitely underweight.

MikeB4

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#952845 16-Dec-2013 06:51

Would seem to be under weight. Does the product state net weight? Also how old was the product as ageing will cause weight loss from drying. That said I would firstly present your findings to the manufacturer and see what they have to say before taking it further.

Here is a crazy notion, lets give peace a chance.

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#952849 16-Dec-2013 07:36

Information here about standards and what you can do about it. I would contact trading standards, personally, they have a lot more power to ensure the company does what it should than an individual.

Byrned

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#952855 16-Dec-2013 08:07

I seem to recall (and this is going back 20 years, so I may not remember it correctly) but the weight of a food product is from the weight of the raw ingredients, that is, before processing. So with any cooking etc. there may be a loss in weight due to water content etc. being released, i.e. a 250g steak is not 250g after it is cooked.

Don't know how that works for bars or what processing may go into them for them to loose content.

Happy to be corrected on this!

Fred99

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#952868 16-Dec-2013 08:29

Product which might lose weight on storage should be marked net weight "when packed".
There could be an exclusion for a pack of six individual bars not for retail sale but average weight 40g / 240g per box. 17% down on the 240g outer packaging label net weight is pretty bad form.
But before dobbing them in (Tasti), drop them an email with your evidence, and see what happens.

bazzer

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#952871 16-Dec-2013 08:38

I'll check a bunch of mine on the digital scales when I get home. I think I have some Tasti.

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andrewNZ

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#952885 16-Dec-2013 09:03

For products like this, the manufacturer uses the "average quantity system" as outlined in this PDF

It states:
Rule 1
The actual contents of the packages in a lot must not be less, on average, than the stated quantity.
Rule 2
Not more than 2.5% of the packages in a lot may be non-standard. A package is non-standard if the quantity is less than the stated quantity on the package by more than a tolerable deficiency (T).
Rule 3
There must be no inadequate packages. A package is inadequate if the quantity of goods is less than the stated quantity on the package by more than twice the tolerable deficiency.

The tolerable deficiency for items under 50g is 9%, so a bar must be 18% under to be inadequate. So on the face of it you have 1 inadequate package, the rest of the packet is bad luck.

Sucks really, but that's how it is.

Edit: to clarify, I'm not an expert on this, I just read the info.

Bung

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#952940 16-Dec-2013 10:19

andrewNZ: The tolerable deficiency for items under 50g is 9%, so a bar must be 18% under to be inadequate. So on the face of it you have 1 inadequate package, the rest of the packet is bad luck.

With the average being 17% underweight is it bad luck or Tasti gaming the system?

"Packers who use the AQS criteria in their production processes as prescribed in the Weights and Measures legislation run the risk of packing under weight/measure product."

sleemanj

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#952945 16-Dec-2013 10:34

andrewNZ: For products like this, the manufacturer uses the "average quantity system" as outlined in this PDF

Interesting, seems to me that the standards are actually quite lax in this regard,

I might go buy another pack or two out of interest from different supermarkets in the next couple of days.

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ubergeeknz

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#952946 16-Dec-2013 10:35

andrewNZ: For products like this, the manufacturer uses the "average quantity system" as outlined in this PDF

It states:
Rule 1
The actual contents of the packages in a lot must not be less, on average, than the stated quantity.
Rule 2
Not more than 2.5% of the packages in a lot may be non-standard. A package is non-standard if the quantity is less than the stated quantity on the package by more than a tolerable deficiency (T).
Rule 3
There must be no inadequate packages. A package is inadequate if the quantity of goods is less than the stated quantity on the package by more than twice the tolerable deficiency.

The tolerable deficiency for items under 50g is 9%, so a bar must be 18% under to be inadequate. So on the face of it you have 1 inadequate package, the rest of the packet is bad luck.

Sucks really, but that's how it is.

Edit: to clarify, I'm not an expert on this, I just read the info.

Think you're ignoring rule 2 which states "not more than 2.5% of the packages in a lot may be non-standard" - all of his bars were non-standard. So unless this is just one box which "happens" to be non-standard where there are 50 more which are within 9%, then it's not up to scratch.

andrewNZ

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#952966 16-Dec-2013 10:58

I'd suggest every muslibar type product will have under and overweight items. This could be a form of scam by the manufacturer, but I doubt it. They all try to stay on the legal side of the line, but they usually do try to stay as close to the line as possible.

I've seen the Tasti production line (quite some time ago). You're looking at a near continuous flow of product, several feet wide. It's mixed in batches at the front end then poured, spread, and squished to a fairly uniform thickness (perfectly uniform is impossible).
The product is cut to a uniform size prior to flow wrapping. Cutting everything to the same sizes does mean that variations in thickness (and therefore weight) will occur.

The products do also pass over check weighers prior to packing, and the inadequate items *should* be ejected from the line.
The check weighers also typically calculate a running average weight to prevent the product average falling too low.

Although the inadequate bar should have been ejected, there are things that could prevent it, including mechanical failure, (deliberately) poor setup, or even plain old human error.
It could even be as simple as a nugget of muslibar getting stuck to the check weigher. At somewhere around 200 items/min, you can pack a lot of product before something like that is noticed.

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andrewNZ

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#952988 16-Dec-2013 11:29

ubergeeknz:
andrewNZ: For products like this, the manufacturer uses the "average quantity system" as outlined in this PDF

It states:
Rule 1
The actual contents of the packages in a lot must not be less, on average, than the stated quantity.
Rule 2
Not more than 2.5% of the packages in a lot may be non-standard. A package is non-standard if the quantity is less than the stated quantity on the package by more than a tolerable deficiency (T).
Rule 3
There must be no inadequate packages. A package is inadequate if the quantity of goods is less than the stated quantity on the package by more than twice the tolerable deficiency.

The tolerable deficiency for items under 50g is 9%, so a bar must be 18% under to be inadequate. So on the face of it you have 1 inadequate package, the rest of the packet is bad luck.

Sucks really, but that's how it is.

Edit: to clarify, I'm not an expert on this, I just read the info.

Think you're ignoring rule 2 which states "not more than 2.5% of the packages in a lot may be non-standard" - all of his bars were non-standard. So unless this is just one box which "happens" to be non-standard where there are 50 more which are within 9%, then it's not up to scratch.

Lot (of packages): A collection of packages containing goods that are
(a) of the same kind
(b) of the same stated weight, measure, or number
(c) available for inspection at the same time and place.
The size of a lot will be determined by the MAPSS Officer at the time of checking. As an example, a lot may be an hour's production run or it may be a stacked quantity of packages not exceeding 10,000.

Bung

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#953003 16-Dec-2013 11:55

A Consumer survey of snack bars concentrating on the health aspect showed competing brands had standard sizes ranging from 20 to 50gms. There's nothing magic about 40. Maybe Tasti's dimensions are more of a natural 30. They would then have kudos for genuine weight rather than threads like this.

sleemanj

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#953015 16-Dec-2013 12:15

Bung: There's nothing magic about 40. Maybe Tasti's dimensions are more of a natural 30. They would then have kudos for genuine weight rather than threads like this.

Oh I agree, there's nothing magic about 40g, I always thought it odd that they put "Big 40g Bars" as an apparent major selling point on the box's branding. But it was precisely because they did do that which led me to weigh them :-)

Mega Nuts makes a big deal of being 40g by bitsyboffin, on Flickr

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sleemanj

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#953190 16-Dec-2013 17:36

Ok, further analysis with a second box of the same Double Choc;
41.1
37.13
40.87
41.79
38.58
39.31
Average: 39.79g (Gross)
The wrapper itself is fairly consistently 1g (and yes my scales can measure down to 0.01g (but lets say 0.1g reliably to be fair)), so we could guess a net weight of 38.79g average. Still less than the 40g advertised in big print.

And a box of "Nutty Crunch" (again Tasti 40g);
44.81
45.38
44.28
44.10
44.25
45.55
Average: 44.72g (Gross)

Conclusions;
a) The first box of Double Choc must have been very unlucky (yes, I re-weighed it along with the others, the bars are also clearly about 1cm shorter than the others which explains it)
b) Tasti's measuring equipment is really not very accurate! You wouldn't think it would be too hard to produce a product that was within a gram either side of a target :/
c) Don't trust advertised product weights further than you can throw them.
d) I shouldn't need to buy snack bars in a while

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James Sleeman
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