As a research chemist I would very much doubt that the materials were made in a "standard lab". While the chemistry involved is relatively low tech, the difficulty is in making the stuff without killing yourself at the same time. This would require a high integrity lab of the sort used in manufacturing highly cytotoxic anti cancer drugs or very strong anaesthetics. This would require airlocks, decontamination areas, using glove boxes and wearing rubber suits with an airhood or BA system. Certainly not what you would find in a standard lab.

In addition, the person applying the nerve agent would have to be trained and using protective clothing. I did note that some Novichok agents were developed so that the final two precursors could be stored separately and only mixed prior to use. The assassin could for instance have put one part of the reagent on the front door and the other part on the door handles of the car, thus the material would only be active when both surfaces were touched in quick succession.

I think Porton Down probably cross referenced samples from the crime scene against their own internally produced standards. They would have made these when the Russian insider whistle blew on the project in order to test their toxicity and potential treatments. They (PD) could only link the material to Russia if they could compare the impurity profile to that of a sample of authentic Russian made material, which I doubt they have access to.

I find the Russian claims that the material used in the assassination attempt came from PD laughable bearing in mind the security at the place and that all scientific staff are vetted prior to employment.

FWIW I do think that the Russian government was probably responsible as they have enough expertise and the motive to carry out such an attack. Proving beyond reasonable doubt that they did it is an entirely different matter.

As a research chemist I would very much doubt that the materials were made in a "standard lab". While the chemistry involved is relatively low tech, the difficulty is in making the stuff without killing yourself at the same time. This would require a high integrity lab of the sort used in manufacturing highly cytotoxic anti cancer drugs or very strong anaesthetics. This would require airlocks, decontamination areas, using glove boxes and wearing rubber suits with an airhood or BA system. Certainly not what you would find in a standard lab.

In addition, the person applying the nerve agent would have to be trained and using protective clothing. I did note that some Novichok agents were developed so that the final two precursors could be stored separately and only mixed prior to use. The assassin could for instance have put one part of the reagent on the front door and the other part on the door handles of the car, thus the material would only be active when both surfaces were touched in quick succession.

I think Porton Down probably cross referenced samples from the crime scene against their own internally produced standards. They would have made these when the Russian insider whistle blew on the project in order to test their toxicity and potential treatments. They (PD) could only link the material to Russia if they could compare the impurity profile to that of a sample of authentic Russian made material, which I doubt they have access to.

I find the Russian claims that the material used in the assassination attempt came from PD laughable bearing in mind the security at the place and that all scientific staff are vetted prior to employment.

FWIW I do think that the Russian government was probably responsible as they have enough expertise and the motive to carry out such an attack. Proving beyond reasonable doubt that they did it is an entirely different matter.