Based on the provided reference materials, there is no specific information regarding the survival or denaturation of RNase or DNase in pure chloroform at a concentration greater than 99%. The references primarily discuss the properties and specifications of chloroform and other reagents used in molecular biology, but they do not explicitly address the effect of such high concentrations of chloroform on these enzymes. Therefore, I cannot definitively answer whether RNase or DNase can survive or will be denatured in pure chloroform at >99% concentration based on the available references.

Chloroform is cheap, experiments are expensive. Just get a small clean bottle and be safe.

It is likely that the DNase is denatured but RNase can readily refold when back in an aqueous environment, which is why it is hard to get rid of RNase. If it were me, I would not risk it.

Also 0.2um filter would remove cells but not most proteins. Even phages and viruses would pass through.

It's probably fine, but like Michael Benedik said it's better to just get a new bottle in case. For what it's worth, our chloroform just says "biotechnology grade" without specifying what that means and other organic solvents like ethanol and isopropanol that we use for extracting RNA for sequencing aren't anything more special than the normal reagent grade stuff marked with "RNA" so people are more careful when using it. But there are always potential issues when working with shared lab reagents of unknown provenance, especially when it comes to chloroform since it can dissolve so many plastics. Definitely had DNA preps end up with mysterious precipitants that I later figured out were probably from people using polystyrene pipettes in the chloroform.