What is the longest English word?

asked by Fred

otorhinolaryngological (22 letters),
immunoelectrophoretically (25 letters),
psychophysicotherapeutics (25 letters),
thyroparathyroidectomized (25 letters),
pneumoencephalographically (26 letters),
radioimmunoelectrophoresis (26 letters),
psychoneuroendocrinological (27 letters)
hepaticocholangiogastrostomy (28 letters),
spectrophotofluorometrically (28 letters),
pseudopseudohypoparathyroidism (30 letters).