Air Purifying
Negative Pressure

  • Not for chemical exposures!
  • P95/P100 (HEPA)
  • Appropriate for RCF, silica dust, lead​

Respirators are devices that selectively purify breathing air. They are essential when working around many chemicals and dusts. When purchasing respirators always make sure it is NIOSH approved. There will be a TC number on the packaging. Always wear the right respirator for the exposure! Different respirators protect against different exposures. Respirators must be worn correctly and there must not be anything interfere with the seal to the face (beards!). Always read and understand the label before using a respirator so that you understand how to wear it correctly and understand its limitations.

Wearing a respirator creates breathing resistance. Talk to your physician before wearing a respirator if:

  • You have Coronary Heart Disease
  • Respiratory Issues (Emphysema, Asthma)
  • Pregnant

Respirators come in a variety of styles and uses:

  • Air Supplied - These are the type of respirator used for unknown atmospheres or atmospheres that are deficient in oxygen. They either have a tank (SCBA) or an airline running to a pump. These types of respirators are almost never used in glass studios and will not be discussed here. 

  • Air Purifying - These types of respirators have some sort of filter. These can be positive pressure (a pump moves the air) or negative pressure (your lungs move the air). There are three main types of Air Purifying Respirators:  

What a Respirator CAN NOT DO:

  • Cannot provide breathing atmosphere (Oxygen)
  • Cannot protect against materials for which it was not intended

How to use a Respirator:

  • Respirators are available in a variety of sizes - make sure you buy the right size for your face.
  • The respirator is properly positioned over your nose and mouth at all times.
  • The top strap or head harness assembly is positioned high on the back of the head.
  • The lower strap is worn at the back of the neck below the ears.
  • Do not buy one strap respirators! They do not fit well.
  • The straps are snug enough to keep the respirator from moving but not overly tight.
  • Nothing (beards, head coverings, etc.) passes between the skin of the face and the respirator’s sealing edge.

Respirator must fit tightly to your face to work properly. Always check the fit:

  • Negative pressure - put your palm over the filter and breathe in - the respirator should slightly collapse on your face and you should not feel a leak .
  • Positive pressure - put your palm over the exhalation valve and breathe out - you should not feel a leak.
  • Do this every time you put on a respirator!

Changing Respirators/Cartridges:

Store the respirator and cartridges in a plastic bag to protect it when not in use. Cartridges should be changed regularly. Replace the dust mask or change the filters when you notice:

  • Increased breathing resistance (dust cartridges)
  • Physical damage to any part of the facepiece or filters
  • The inside of the dust mask becomes unsanitary
  • Time use limitations for the specific respirator require replacement
  • If smell, taste or irritation from the contaminant(s) is detected

Particulate Respirators - What does N95/P95/P100 mean?

What a respirator CAN DO:

     Filtering Facepiece:

     Elastometric - Particulate

     Elastometric - Chemical

Filtering Facepiece

  • Variety of chemical-specific cartridges available
  • Organic Vapor, Acid Gas most common
  • Always insure you select the correct filter for the exposure


Air Purifying
Positive Pressure

  • Dust/Fume/Mist
  • Throw-away type bought at Home Depot, Lowes
  • Good for nuisance dust, paint (latex) mist
  • Does NOT work for chemical vapors (acetone, ammonia, etc.)
  • Does NOT work for gases (carbon monoxide, sulfur dioxide, etc.)​

Protection Factors:

  • Indicator of the effectiveness of a particular type of respirator
  • Assigned by NIOSH
  • Exposure Limit X Protection Factor = Level of Protection
  • Example: 5 mg/m3 X 10 = Respirator is effective for exposures up to 50 mg/m3

PAPR - Power Air

Purifying Respirator


Air Purifying
Negative Pressure