Particularly Hazardous Substances (PHS)
The OSHA Laboratory Standard (29 CFR 1910.1450) defines a Particularly Hazardous Substance (PHS) as a select carcinogen, reproductive toxin, and/or a substance with a high degree of acute toxicity. They define PHS as chemicals meeting any of these criteria:
Carcinogens
A carcinogen is a substance capable of causing cancer. This can be attributed to any agent that can initiate or speed the development of malignant or potentially malignant tumors, malignant neoplastic proliferation of cells, or cells that possess such materials. These agents are chronically toxic substances; that is, they cause damage after repeated or long-duration exposure, and their effects may become evident only after a long latency period. A chemical is considered a carcinogen if it is included in any of the following carcinogen lists:
- OSHA-regulated carcinogens as listed in Subpart Z of the OSHA standards.
- Under the category “known to be carcinogens” in the Annual Report of Carcinogens published by the National Toxicology Program (NTP), the latest edition.
- Group 1 (“carcinogenic to humans”) of the International Agency for Research on Cancer (IARC), latest edition. Chemicals listed in Group 2A or 2B (“reasonably anticipated to be carcinogens”) that cause significant tumor incidence in experimental animals under specified conditions are also considered carcinogens under the OSHA Laboratory Standard.
Below reflects the GHS hazard categories for a chemical carcinogen that would be considered a PHS:
| Hazard Code | Hazard Statement | Hazard Class | Hazard Category | Pictogram |
|---|---|---|---|---|
| H350 | May cause Cancer | Carcinogenicity | Category 1A, 1B | |
| H351 | Suspected of Causing Cancer | Carcinogenicity | Category 2 |
Below are examples of chemical carcinogens:
- Acrylamide
- Benzene
- Chloroform
- Formaldehyde
- Methylene Chloride
- Tamoxifen
Reproductive Toxicants
Reproductive toxins are substances that have adverse effects on various aspects of reproduction, including, fertility, gestation, lactation, and general reproductive performance. When a pregnant woman is exposed to a chemical, the fetus may be exposed as well because the placenta is an extremely poor barrier to chemicals. Reproductive toxins can affect both men and women. Male reproductive toxins can in some cases lead to sterility. Germ cell mutagens are classified as reproductive toxins as they may/are suspected of causing permanent changes in the amount or structure of the genetic material in a cell.
Below reflects the GHS hazard categories for a reproductive toxin that would be considered a PHS
| Hazard Code | Hazard Statement | Hazard Class | Hazard Category | Pictogram |
|---|---|---|---|---|
| H340 | May cause genetic defects | Germ Cell Mutagenicity | Category 1A, 1B | |
| H341 | Suspected of causing genetic defects | Germ Cell Mutagenicity | Category 2 | |
| H360 | May damage fertility or the unborn child | Reproductive Toxicity | Category 1A, 1B | |
| H361 | Suspected of damaging the fertility of the unborn child | Reproductive Toxicity | Category 2 | |
| H362 | May cause harm to breastfed children | Reproductive Toxicity, Effects on or via lactation | N/A | N/A |
Below are examples of reproductive toxins:
- Arsenic
- Cycloheximide
- Glycol Ethers
- Hexane
- Lead and Mercury Compounds
- Toluene
Acute Toxicity
High acute toxicity includes any chemical that falls within any of the following OSHA-defined categories:
- A chemical with a median lethal dose (LD50) of 50 mg or less per kg of body weight when administered orally to certain test populations.
- A chemical with an LD50 of 200 mg less per kg of body weight when administered by continuous contact for 24 hours to certain test populations.
- A chemical with a median lethal concentration (LC50) in air of 200 parts per million (ppm) by volume or less of gas or vapor, or 2 mg per liter or less of mist, fume, or dust, when administered to certain test populations by continuous inhalation for one hour, provided such concentration and/or condition are likely to be encountered by humans when the chemical is used in any reasonably foreseeable manner.
Below reflects the GHS hazard categories for a substance that are acutely toxic and would be considered a PHS:
| Hazard Code | Hazard Statement | Hazard Class | Hazard Category | Pictogram |
|---|---|---|---|---|
| H300 | Fatal if swallowed | Acute toxicity, Oral | Category 1,2 | |
| H310 | Fatal in contact with skin | Acute toxicity, Dermal | Category 1,2 | |
| H330 | Fatal if inhaled | Acute toxicity, Inhalation | Category 1,2 | |
| H370 | Causes damage to organs | Specific target organ toxicity, Single exposure | Category 1 | |
| H371 | May cause damage to organs | Specific target organ toxicity, Single exposure | Category 1 |
Below are examples of substances that are acutely toxic:
- Acrolein
- Methyl Fluorosulfonate
- Osmium Tetroxide
- Phosgene
- Sodium Azide
- Sodium Cyanide
Unknown Toxicity
Some substances, like novel therapeutics, do not have all of their hazards recorded, as testing might not have been conducted/completed on it yet. These substances can be labeled as “unknown acute toxicity” on the label and the SDS where the chemical mixture is already classified as acutely toxic for a particular route of exposure, and there are one or more other “relevant ingredients” of unknown acute toxicity for that particular route. If there is no acute toxicity data for the mixture, then it is required that classification can be based on bridging principles. If bridging principles cannot be applied, classification is based on the ingredients of the mixture.