Advanced Photon Source

An Office of Science National User Facility

Materials Hazard Class Definitions

Hazard: Any existing or possible condition that, by itself or through interaction with other conditions, has the capacity to cause death, injury, illness, property damage, unacceptable environmental impact, or other losses.

Risk: A quantitative measure (or estimate) of the product of the probability that a hazard will result in ill-effect and the consequence of an ill-effect.
Toxic: Having the capacity to cause death, illness, or diminished function. A material that meets one or more of the following criteria should be considered toxic:

  • Has a published LD50 equal to or less than 0.5 g/kg of body weight.
  • Has a published LC50 equal to or less than 1000 ppm.
  • Has an OSHA permissible exposure limit (PEL) or ACGIH Threshold Limit Value (TLV) equal to or less than 5000 ppm.
  • Has an OSHA PEL or ACGIH TLV equal to or less than 10 mg/m3.

Biohazard: An agent of biological origin (e.g., all infectious organisms, their toxins, allergens of biological origin, and genetic fragments) that has the capacity to cause ill-effects in humans.

Carcinogen:  A carcinogen is a substance that causes cancer (or is believed to cause cancer).  If a mixture has not been tested as a whole to determine whether the mixture is a health hazard, the mixture shall be assumed to present the same health hazards as do the components which comprise one percent (by weight or volume) or greater of the mixture, except that the mixture shall be assumed to present a carcinogenic hazard if it contains a component in concentrations of 0.1 percent or greater which is considered to be a carcinogen under paragraph (d)(4) of this section of the U.S. OSHA Hazard Communication Standard, 1910.1200(d)(5)(ii).  A list of chemicals considered carcinogens is kept by NIOSH.  Please also see the ANL ESH Manual for a list of select carcinogens.

Corrosive:  A chemical that causes visible destruction of, or irreversible alterations in, living tissue by chemical action at the site of contact. For example, a chemical is considered to be corrosive if, when tested on the intact skin of albino rabbits by the method described by the U.S. Department of Transportation in appendix A to 49 CFR part 173, it destroys or changes irreversibly the structure of the tissue at the site of contact following an exposure period of four hours. This term shall not refer to action on inanimate surfaces (OSHA definition). Material particles intentionally created (in contrast with natural or incidentally formed) materials with structures having dimensions of less than 100 nanometers. Nanoparticles are dispersible particles having in two or three dimensions greater than 1 nm and small than about 100nm and which may or may not exhibit a size-related intensive property. ENM exhibit novel properties that are related to their physical size and structure as well as chemical composition. A general uncertainty exists as to whether the differing novel properties of nanomaterials constitute increased occupational health or environmental risks. Activities that involve handling of dispersible engineered nanoparticles should be subject to the most rigorous control regimens, e.g., working in glove boxes, glovebags, or ventilated partial enclosures like laboratory chemical hoods, wearing gloves, or wearing respirators. Control of skin contact and mist inhalation should be addressed for suspensions of nanoparticles in fluids. Handling a solid matrix with imbedded (fixed) nanomaterials or carrying out processes in sealed vessels that isolate workers from contact with engineered nanoparticles might require no additional safeguards during normal operations. However, maintenance operations on normally sealed vessels or ventilation systems may create hazards requiring exposure of controls.

Explosive: The term "explosive" or "explosives" includes any chemical compound or mechanical mixture which, when subjected to heat, impact, friction, shock, detonation or other suitable initiation, undergoes a very rapid chemical change with the evolution of large volumes of highly heated gases which exert pressures in the surrounding medium.  The term applies to materials that either detonate or deflagrate. Reference: DoD 4145.26-M

Flammable: Susceptible to ignition during storage, normal handling, or use. The term includes, but is not necessarily limited to:

  • All materials that ignite spontaneously when exposed to air.
  • All gases easily ignited in atmospheres containing approximately 21% oxygen.
  • All liquids having a flashpoint below 100° F (38° C).
  • All combustible solids and liquids having a physical form that makes them easily ignitable if dispersed into ambient atmospheres.

Oxidizer:  A chemical other than a blasting agent or explosive as defined in 1910.109(a) of The OSHA Hazard Communication Standard (HCS)
(Subpart Z, Toxic and Hazardous Substances, 29 CFR 1910.1200), that initiates or promotes combustion in other materials, thereby causing fire either of itself or through the release of oxygen or other gases.

Radioactive: Any material having a measurable specific activity above background. While on the ANL site, all radioactive materials (including radioactive samples/materials that are not regulated by the US Department of Transportation) must be transported by the ANL Special Materials Group. APS must be notified of any shipment of radioactive materials to/from the site.

Other: Can include any other hazard not listed.