It's here that those items which are deemed up to scratch are awarded the coveted BSI Kitemark, found on goods ranging from double glazing and plugs to contraceptives. And there's almost nothing they won't test - often to destruction.
Once through reception, I'm taken into a building like a giant university physics lab. I'm introduced to one of the three lab managers, Mark Mayo, and away we go. Our first stop is the crash helmets testing station, a place full of creepy-looking aluminium crania known as 'headforms'. The helmet is put on a headform and then dropped from a tower onto surfaces that simulate impacts with roads, curbstones and pointy objects; various stress and deceleration readouts appear on a screen. It's interesting to watch, if rather gruesome - you can't help imagining the flesh-and-bone reality that the tests represent.
They used to test cricket balls here, says Mayo. Occasionally, they still do for the English Cricket Board, but it's not terribly economic. BSI may be a not-for-profit organisation, but it is independent and has to pay its own way. Someone makes a remark about counting the stitches on the balls. It's not a joke: they really used to do that. I'm also told that, as standards go, the BSI's Kitemark is a superior breed; the EU CE mark often isn't as rigorous.
We leave one lab and enter another, and another. Here, fire extinguishers are tested for use on ships by having corrosive brine sprayed at them for 20 days; there, smoke alarms are put through their paces (software bugs are a common problem); over there, sensor circuits are shaken for hours in ovens and freezers.
The biggest objects they test are motorway signs. Test rigs are everywhere, many of them made in BSI's own workshop - insulated smoke tunnels capable of sub-zero temperatures are not the kind of thing you can buy on Amazon.
We head into the lighting lab - a black dungeon-like room equipped with a giant, perfect mirror which reflects light down a 20m tunnel; car lamps and traffic lights are tested here.
I ask if I can go up to the latex lab where gloves - and, yes, condoms - are tested. I know, I know, it's all a bit obvious. But you wouldn't visit Paris without seeing the Eiffel Tower, would you? In the lab, there's a row of Perspex-fronted cupboards, each with, well, plastic prongs for the condoms to go on. Our guide puts on a set of gloves (the condoms are covered with lubricant) and rolls the condoms down the plastic protuberances - a bit like a high-tech sex-ed class.
The cupboards are closed and the condoms inflated. Gratifyingly, they blow up to Hindenburg proportions before they pop. We look at the graph of their failure. All have comfortably exceeded spec. An acceptable failure rate is something like two in a batch of 315, which presumably is why condoms are said to be 99% effective. Every single batch of Kitemarked condoms is tested - this means most brands are checked at least once a month.
Finally, I get down to doing a little testing myself. First, we fire ball bearings at a pair of plastic safety goggles at speeds of up to 195 m/s. The battered goggles have clearly been hit dozens of times before, but, to their credit, shrug off this latest salvo. I'm impressed.
Next, I test a dust mask of the sort builders use. I put it on and walk on a treadmill in a kind of Perspex phone box while a fine saline mist is sprayed into it.
A pretty eccentric job then - and one that pays between £20,000 and £40,000 p.a. It's not uncommon for staff to stay at BSI for 20 years. In some ways, this is hardly surprising. If you have the frame of mind that enjoys fiddling with radios and building gadgets and taking things apart, it would be a dream job - in fact, it would hardly seem like work at all.