How to remove varnish<br>Create good ventilation. Whether your sanding or using a chemical solvent, it's a good idea to have ventilation. Open windows and use fans to create cross-ventilation if you're inside.
It is healthier to remove varnish in a ventilated area.
It is healthier to remove varnish in a ventilated area as opposed to an area that contains the fumes.  They system was likely confused by the comparison.
( z1 have-degree :ARG1 ( z2 remove :ARG1 ( z3 varnish ) :location ( z4 area :ARG1-of ( z5 vent ) ) ) :ARG2 ( z6 healthy ) :ARG3 ( z7 more ) )