| Term | Definition |
|---|---|
| Radiant Heat Transfer |
Radiant heat transfer occurs when there is a large difference the temperatures of two No surfaces that are exposed to each other, but are not touching. |
| Radon |
A radioactive gas formed by the decay of uranium. |
| Radon progeny |
Radon particles that can be breathed into the lung, where they continue to release radiation as they further decay. Also known as radon decay products or radon daughters. |
| Re-entrainment |
Situation that occurs when the air being exhausted from a building is immediately brought back into the system through the air intake and other openings in the building envelope. |
| RELs |
Recommended Exposure Limits (recommendations made by NIOSH) |
| Reproductive Toxicant |
A chemical acting as a poison by means of causing adverse effects on the male or female reproductive system (e.g. fertility, pregnancy outcomes). |
| Respirable Particles |
Those particles found in air that are capable of penetrating and being deposited in the deeper (non-ciliated) portion of the lung. |
| Rigidity |
Muscle tone is high and there is continuous contraction and resistance to passive movement. |