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Temperature and Relative Humidity | Guidelines for Temperature and RH | Pollutants | Guidelines for Pollutant Levels | Light | Guidelines for Light Levels
Guidelines for Pollutant Levels
There are no formal standards for pollutant levels in collection storage areas, but generally accepted levels for particulate filtration are given in NISO's Environmental Guidelines for the Storage of Paper Records:
| Combined stack and user areas | 60-80% filtration (e.g., remove 60-80% of particulates 1 micron diameter or larger) |
| Stack areas, users excluded except for retrieval | 90-95% filtration |
| Optimum preservation areas | >95% filtration |
Generally accepted levels for sulphur dioxide, nitrous oxides, and ozone (the most common gaseous pollutants in collection storage areas) have been given in numerous publications and fall in the following ranges:
| Sulphur dioxide | 1-10 micrograms/cubic meter |
| Nitrous oxides | 5-10 micrograms/cubic meter |
| Ozone | 2-25 micrograms/cubic meter |
It is important to be aware that the upper limits for exposure of collections to pollutants are well below the acceptable levels for human exposure set by the Environmental Protection Agency. Thus, "safe" levels of pollutants for people are not considered "safe" for collections.
