This is a new one on me. The usual term for what you have in mind is, I think, 'scientism', which can be chaacterised roughly as follows :
... there are no real limits to the competence of science, no limits to what
can be achieved in the name of science. Or, if there are limits to the scientific
enterprise, the idea is that science, at least, sets the boundaries for what we
humans can ever achieve or know about reality. There is nothing outside the
domain of science, nor is there any area of human life to which science cannot
successfully be applied. (Mikael Stenmark, 'What Is Scientism?', Religious Studies, Vol. 33, No. 1 (Mar., 1997), pp. 15-32 : 15.
Since this is a claim, and not an arguments with premises and conclusion, it can't be a fallacy though it can of course be false.
A circularity in the defence of scientism
Epistemology... shapes the constraints of science only in light of the acknowledged ends
and purposes of science. The touchstone of correct epistemology is the better achievement
of scientific goals based on the changes in scientific method. The traditional epistemologist
looks for guidance- for standards of justification - elsewhere than in the practice of science.
The Quinean epistemologist looks to science ... [W]e hold science (and epistemology)
liable to no other standard than what smooths the way for ongoing [scientific] research... ( Roth, P.: 1987, Meaning and Method in the Social Sciences, Cornell University Press,
Ithaca, New York : 33.)
Criticising this position, James Maffie argues as follows :
Epistemology becomes "science self-applied" by being reduced to epistemology of science which in turn is reduced to the self-critical offices
of science itself. The epistemology of science is all the epistemology we
need. Epistemic rationality is equated with scientific rationality. Cognition
is epistemically liable to no other norms than scientific norms; and these
are epistemically liable to no other goals than scientific goals. Identicists
interpret claims about the absence of standpoints independent of science,
etc., as saying that epistemic goals, norms and concepts are identical to the
evidential goals, norms and concepts of science. So, rather than eliminate
epistemic value, warrant and norms, identicists equate them with scientific
value, warrant and norms. General epistemic questions about evidence,
rationality and knowledge, for example, become scientific questions about
scientific evidence, rationality and knowledge. (James Maffie, 'Naturalism, Scientism and the Independence of Epistemology', Erkenntnis (1975-), Vol. 43, No. 1 (Jul., 1995), pp. 1-27 : 3.)
In other words, there can be no knowledge or epistemology independent of science, since science defines or is the criterion of what counts as knowledge or epistemology. But as stated this is merely a claim; and a circular one : all knowledge or epistemology is science since what isn't science isn't knowledge or epistemology. This is, or is meant to be, an impenetrable circle. And indeed the circle is impenetrable if we allow a proponent of scientism to stipulate the use or meaning of terms in this way. But short of argument for it, we have no reason to accept the stipulation.
A different response to scientism is offered by social constructionist positions. Such positions seek to undermine the independent status of science as the arbiter of knowledge and epistemology by the rug-pull of arguing that what counts as science is itself a decision made by social actors. Science is a social reality but social realities are framed by social actors and have no autonomous existence.
I am not so much opposed to social constructionism as uncertain what, if accepted, it proves. But it seems to me to contain an important element of truth. It is a matter of social determination or decision what counts, for instance, as the activity of being a historian, or that of an archaeologist, or that of a politician. Not necessarily of easy or clear-cut decision, but still of social decision. I don't see why the same should not be true of the activity of being a scientist. In which case, not all knowledge is scientific knowledge since the knowledge that someone is a scientist or that some inquiry or activity is scientific is not itself scientific but embodies a social decision : and a decision is not knowledge.
On social constructionism see :
Steve Fuller, Science (Concepts in Social Thought), ISBN 10: 0816631247 / ISBN 13: 9780816631247. Published by University of Minnesota Press, 1997
Ian Hacking, The Social Construction of What?, ISBN 10: 0674004124 / ISBN 13: 9780674004122. Published by Harvard University Press, 1999.