This was their response:
I have a question about the history of an MSA product. It is my understanding through online research that back in the 1960s-70s, MSA produced a fire helmet under the Topguard or Topgard name. I understand that currently, MSA produces a safety (non-FF) helmet under the Topgard name. Is the name of the older fire helmet correctly spelled Topguard or Topgard? If it is Topgard, why was the design changed from a fire helmet to a safety helmet? On the other hand, if the old fire helmet is correctly spelled Topguard, was there also a Topgard safety helmet in production at the same time? When was the Topgard safety helmet first introduced?
At some point in the mid-1980s, NFPA-1971 changed significantly enough that we could no longer offer the Topgard as a structural firefighting helmet. We've continued to market its cap & hat versions, though, as our industrial Topgard helmet. Regardless of the model, each version was part of the Topgard "family." This model was launched in the 1960s.