NIOSH ratings

The **NIOSH ratings** are a set of rules that NIOSH uses to check respirators. Today, the rules NIOSH uses is called **42 CFR 84**. NIOSH uses these rules to check N95 respirators. Before the N95, other rules have been used in the past, like 30 CFR 11. Also, some less-seen respirators can have filters that can be changed. These respirators are called elastomeric respirators. See the last chart for other less-seen respirators. NIOSH checks all these less-seen respirators too.

Under 42 CFR 84, rules for chemical filters are also made by the American National Standards Institute. One rule is called ANSI K13.1-1973, which are rules for chemical cartridge colors. A new set of rules under ANSI K13.1-1973 is called ANSI Z88.7-2001. To stay simple, ANSI's color rules are _not_ listed below.

### Bureau of Mines

The first respirator rating rules were made due to miners dying. By 1907, 3,243 miners had died. The United States Bureau of Mines (USBM) was made to give out information for miners and mine owners, so fewer miners would die. Some respirator rules were made, but few wanted rules that had to be followed.

Then, in 1929, the Hawks Nest Tunnel Disaster happened. The number of dead was so great from the breathing of silica (silicosis), that the USBM had to make respirator rules that people had to follow. The rules at the time checked respirators with dust that made people sick. Each dust rule is checked by itself before being passing the check. They were:
- Type A - **Dust**
- Type B - **Fume** - tested with lead fume
- Type C - **Mist**
Soon, "Type A/B/C" was seen less over time. People often said 'Dust/Fume/Mist' in place of 'Type A/B/C'. And often, respirators passed most of the 'Dust', 'Fume', and 'Mist' rules.

"Dust/Mist" referred to the same test dust: silica. See the chart below for the rules.

### MSHA/NIOSH - 30 CFR 11

The Federal Coal Mine Health and Safety Act made the Mine Safety and Health Administration (MSHA). At the same time, the Occupational Safety and Health Act of 1970 made NIOSH. Soon, both US government agencies checked that respirators followed rules under '30 CFR Part 11'. 30 CFR 11 rules include a MSHA-NIOSH approval label, which can be seen in the picture.

30 CFR 11 rules were the same as USBM rules. But, the 30 CFR 11 rules added HEPA rules for respirators. The most used rules are below:
|Dust used with rule|Respirator rule or 'approval'|Dust pass from filter, to the mouth and nose, by rule|Percentage of dust _not_ passed to the mouth and nose|
| --- | --- | --- | --- |
|158.4 milligram (mg) silica air|Use-one-time 'Dust/Mist' respirators|1.8 mg|98.86%|
|158.4 mg, most likely silica air|Respirators with 'Dust/Mist' filters that can be changed|1.5 mg|99.05%|
|0.3 micron Dioctyl phthalate0.05 milligram per cubic meter air for other dust|HEPA (most likely also follows 'Dust/Mist' rule or approval)|No information|99.97%|

Some abbreviations of these respirators include: 'DM' and 'DFM', which are 'Dust/Mist' and 'Dust/Fume/Mist' ('Fume' is not in the chart above).

In 1973, the Los Alamos National Laboratory said NIOSH should use salt to check DM and DFM respurators. The amount of dust _not passed_, using salt, was really 75% to 90%. Using silica made the respirators look better than they actually were.

## Ratings today, under 42 CFR 84

In 1995, NIOSH made new respirator rules. The rules are stored in 42 CFR 84 in the Code of Federal Regulations (CFR). The CFR is part of the Federal Register. HEPA, or 'HE', is now only used for powered air-purifying respirators. In 2020, new ratings were added for these respirators. They were PAPR100-N and PAPR100-P. HEPA for other respirators is now 'P100'. P100 is the only type of filter or respirator that can have the color magenta. Also, the NIOSH approval label for 42 CFR 84 is not the same as the label for 30 CFR 11.

Under the new rules, MSHA stopped checking respirators. Also, in the United States, it is against the rule of law to sell things that are not respirators with these rules or ratings. Respirators that are not checked by NIOSH should also not be sold.

Under 42 CFR 84, respirators should be tested with salt dust if the rating starts or ends with the letter 'N'. The amount of salt dust is 200 milligrams (mg). Dioctyl phthalate is used if the rating starts or ends with the letter 'R' or 'P'. 'R' and 'P' mean the respirator or 'filter' is made to stop oil mist. For 'R', the amount of DOP mist used is 200 mg. For 'P', the amount of DOP mist used does not have a number. It does not stop for a long time. All the new ratings are below:

|Dust used with rule|Respirator rule or rating|Percentage of dust _not_ passed to the mouth and nose||
| --- | --- | --- | --- |
|rowspan=4|NaCl (N) or DOP (R,P)|N95, R95, P95|95%|
|N99, R99, P99|99%|||
|N100, R100, P100|rowspan=2|99.97%||
|HE, PAPR100-N, PAPR100-P||||

If the rating ends in 100, the respirator or filter can stop asbestos.

## Last chart: Type of respirator by TC number

This chart shows which less-seen respirator each TC number goes to. This can be used to check if a respirator is real in the NIOSH _CEL_.
|US Code|Gas mask|Air-line|SCBA|Particulate|PAPR|Chemical Cartridge|
| --- | --- | --- | --- | --- | --- | --- |
|Bureau of Mines (shown on the respirator as 'BM')|BM-14|BM-19|BM-13|BM-21|N/A|BM-23|
|30 CFR 11|TC-14G|TC-19C|TC-13F|TC-21C|TC-21C|TC-23C|
|**42 CFR 84 (used today)**|TC-14G|TC-19C|TC-13F|**TC-84A**|TC-21C|TC-23C|

N95s use the TC number 'TC-84A'.

## Other websites

- NIOSH _CEL_
- NIOSH Pocket Guide to Chemical Hazards will tell you what respirator to use for bad chemicals.

## Related pages

- Gas mask
- N95

## Infobox (regulated ppe)

- **image**: Elastomeric respirator exploded view (Respirator types snapshot at 1024).png
- **caption**: An elastomeric respirator with changeable filters. What is less known is that they can have N95 filters too.