What ho all self isolators and bubble groups,

This is kind of a grumpy old man rant, but I don't understand why so many of the plastic items that are used in the home, are just rubbish. I don't mean the item itself, usually just the plastic case.

They come out of the box, white; within a few years, they have discoloured to beige. I know the excuse is UV light, but I would counter that argument by saying that light switches, 13A sockets and white plastic toilet seats do not discolour.

My Firex alarms smoke and heat alarms, started white, more or less matching the ceiling, now beige. The alarm RKP, again, white from the box, now a tone of yellow. The supply and extract MVHR ceiling vents are factory painted, but some are now a nice tone of beige. As for the expensive Ideal Standard, vac formed bath panel, the only white section is where the bath mat drapes. It is so beige, it really shows against the white bath and tiles.

None of these items are in direct sunlight but obviously UV reflects around.

However, I still question why these items are not designed with a better formulated plastic?

I have complained to the manufacturers and not surprisingly, their response is 'tough luck kid, buy another.'

As it happens, I have 'solved' the issue by spraying white. And for the smoke alarms, I did dismantle rather than spray the smoke sensor and tested when re-installed.

Toodle pip

Different types of plastic, I expect.

You are correct about the casings being made in China. But I cannot see them even being made in the UK. I just don't understand why, if light switches can be so resistant to UV, etc, why not these other items for which we pay and arm and a leg?

In our kitchen, bathrooms and utility, I did not want tiles so have one piece vinyl. If noting else, figure in 'wet' areas, I would rather have a continuous covering to protect the timber below. And that vinyl goes under the kitchen cabinets, into the pantry and into the cupboard with the boiler and cylinder. They never get any UV whatsoever. And for whatever reason, the vinyl is now a noticeable shade of 'yellowish' when compared with the normal, regularly walked on vinyl.

I have an external grade PIR for the garage 'welcome' lights. The dome has more or less collapsed due to UV. Called the manufacturer and was told that the item only has a 5 year design life!!!!!

But the uPVC facias, of which I have too much (but it does mean that I don't have to paint,) they are still white after 10 years in the direct sun.

I'm no expert in the field of thermoplastic polymers but I'm guessing there are dozens, if not hundreds of types and formulations each with their own particular desirable and undesirable properties.
Take white light switches for example I think they are generally a Melamine formulation, also used for plastic picnic/party/dinnerware. It's quite tough and seems to retain its colour well and moulds to a nice clean finish, but if, for instance, you're trying to knock a cable entry into a patress box you have to be carful not to break it. The toughness comes with a certain degree of brittleness. I imagine if you then introduce some flexibility into the mix you may loose the colour retention and /or the injection moulding properties.