How to open Winsor & Newton impossible to open childproof bottles
These are the childproof plastic bottles for linseed oil, artist's painting mediums, varnishes etc that are manufactured by (or for) Winsor & Newton who make fine art materials. The bottles can just about be opened by hand when new—after that they are almost impossible to open by anyone. You are supposed to press the cap down then twist it open but it requires massive force and even then it may not work if there is any product residue on the bottle-top thread. The risk of physical injury seems high.
There is a solution. I put on some tough leather gloves and prise off the black plastic outer cap with a flathead screwdriver. This breaks the product but you can then twist off the transparent plastic inner cap in the normal fashion. Of course the bottle is no longer childproof but I suppose it might be possible to snap the black outer cap back on temporarily (I don't bother with this because no-one in my house is trying to drink linseed oil).
Winsor & Newton have failed here in my opinion. They should have tested the cap system properly and made sure it works before putting it on the market. Apparently they know about and have (supposedly) rectified the problem but this is not evident on the products I've bought this year (
and won't be buying again I have bought them again; other manufacturers use the same type of bottle).
I do not hold myself out as a child safety or packaging expert and I am not arguing against childproof packaging but I think it should be safe for adults as well—artists in this instance. The method above is what I've used as an adult and a child might then be able to open the bottle; it must obviously be kept in a safe place where it is not accessible to children (as is the case with, for example, tubes of paint which do not have childproof caps but contain pigments that may be more hazardous than oils, mediums, solvents etc).
Update: sometimes the inner cap gets stuck to the outer one (if the bottle contains drying oil or whatever). The screwdriver then brings them both off at once and they can't be separated. If that happens, I remove the sealing disc up inside the inner cap. After that the joined-up cap should unscrew more easily without too much force.