That was Porton Down. The British chemical warfare laboratory. Lavrov is quoting Spiez, an independent Swiss lab, one of five used by OPCW. They said that BZ was the toxin used, but they were puzzled at the presence in the sample of A234, which is a novichok, as they are highly volatile and presumably would be expected to have evaporated by the time they received the sample.
If the toxin was BZ, that would explain why Porton Down were weasel worded. Because it wasn’t a novichok.
