Toilet Seat at Work Has Month/Year Chart on Underside -- What Is It?

November 14, 2004 8:53 PM

The toilet seat at my place of work has a chart like this embossed on the underside. Clearly months and years, with a period of them checked off with little bumps. What could it possibly mean? The chart is about 5cm x 5cm in size.
posted by Jimbob to Grab Bag (10 answers total)

A maintenance record? Or a spot to mark when it should be replaced?
posted by dual_action at 9:00 PM on November 14, 2004

Up to what date is it marked off? Could it be production date, to be able to trace back when defects arose? Seems a bit elaborate for a toilet seat though.
posted by fvw at 9:13 PM on November 14, 2004

Response by poster: The dots I've marked off are not the precise ones as on the toilet seat - although it is the approximate range (some time in '89 till some time in '97). The spots are actually raised bumps on the plastic, so I don't think it's something that's been added to over time, like a maintenance record, but more like something that's been moulded as part of the seat on manufacture.

Also, to my knowledge, the relevant bathroom was remodelled in about 2000, so the dates don't even appear very relevant.
posted by Jimbob at 9:53 PM on November 14, 2004

I bet it's the manufacturing date.

They've got one mold for the toilet seat, or a few copies of the same mold. Whenever the month changes, they cut out another divot in the mold. This causes a raised bump for the current month. Since it's hard to fill in the divots, they have raised bumps for every month prior to the current month too.

Like you say, the only problem with this theory is that the toilet seat would have had to have sat in inventory for three years.

"Would have had to have." Terrific!
posted by tss at 10:34 PM on November 14, 2004

I'm guessing it's a date of manufacture. The mold for the seat was probably created some time in 1989. For each month afterward, you would add a little divot in the mold, which would come out in reverse as a raised dot on each seat. Sort of like this method to mark book editions that works by removing something from the printing plate. But I'm just guessing.
posted by stopgap at 10:39 PM on November 14, 2004

Looks like I was beat to the punch. We both even used the word "divot."
posted by stopgap at 10:39 PM on November 14, 2004

It's clear to me that lots of plastic products are marked with their date of manufacture this way; I've never understood why, though.

My best guess is to make it easier to identify items with manufacturing defects - say the mold cracked in February 1995, and they caught on in August; they'd be able to identify the defectives more easily. Or if the CPSC took issue with a particular batch or something.
posted by ikkyu2 at 10:54 PM on November 14, 2004

Response by poster: The problem, as I see it tss + stopgap, is that the divots don't start at the first date...although I guess it's reasonable to assume that the mold might have been around for a while (ie. in 1988) before they started using it and marking off months.

Hmm, it's starting to make sense.
posted by Jimbob at 10:59 PM on November 14, 2004

The mold had to be *made*, then shipped to the facility that would be making the seats. Most plastic things have something like this. Some of them also have date, day, time of day...which is indicated by little dials.
posted by notsnot at 5:21 AM on November 15, 2004

Best answer: It's, as noted a manufacturing date. Most standards now require the traceability for products produced that have an impact of function or safety. If there was a defect that would require that it be replaced they would identify the product by those markings. For example most car parts are identified by year, month, day and in some cases shift and in critical components like airbags, sequence.
posted by mss at 11:32 AM on November 15, 2004