{"id":81,"date":"2026-07-16T13:14:33","date_gmt":"2026-07-16T17:14:33","guid":{"rendered":"https:\/\/www.clarku.edu\/environmental-health-and-safety\/?page_id=81"},"modified":"2026-07-16T13:18:16","modified_gmt":"2026-07-16T17:18:16","slug":"materials-labeling-and-signage","status":"publish","type":"page","link":"https:\/\/www.clarku.edu\/environmental-health-and-safety\/materials-labeling-and-signage\/","title":{"rendered":"Materials labeling and signage"},"content":{"rendered":"\n
\n
\n
\"Hazardous
Example of a hazardous waste label.<\/figcaption><\/figure>\n\n\n\n

Labeling is required by law. The container must provide the full name of the substance with no abbreviations. In addition, hazardous chemicals must also contain basic warning information. The basic warning information is the following: The chemical lab group the waste originated from, full name of the chemical waste (no abbreviations), percentage of chemical waste constituents to total 100%, hazardous designation (ignitable, toxic, reactive, or corrosive), and the full date when each bottle has been filled to 80% capacity.<\/p>\n\n\n\n

When reusing a container, make sure you either remove or completely deface old labels to avoid confusion. Inspect labels and replace those that are hard to read or have fallen off. Good labeling practices avoids accidents and reduces the disposal cost of chemicals by eliminating subsequent unknowns.<\/p>\n\n\n\n

National Fire Protection Association labeling<\/h2>\n\n\n\n

NFPA<\/a> uses a symbol system designed as a diamond-shaped label containing four differently colored squares. A number (0-4) or an abbreviation is added to each square indicating the order of hazard severity. The higher the number, the greater the hazard.<\/p>\n\n\n\n

NFPA Labeling System<\/h3>\n<\/div>\n\n\n\n
<\/div>\n<\/div>\n\n\n\n
\n
\n
\n

Red background = flammability<\/h4>\n<\/div>\n\n\n\n
\n

4 \u2013 flash point < 73\u00ba F
3 \u2013 flash point < 100\u00baF
2 \u2013 flash point > 100\u00baF to < 200 \u00baF
1 \u2013 flash point > 200\u00baF
0 \u2013 will not burn<\/p>\n<\/div>\n<\/div>\n\n\n\n

\n
\n

Yellow background = reactivity<\/h4>\n<\/div>\n\n\n\n
\n

4 \u2013 Explosive at room temperature. 3 \u2013 Shock and heat may detonate
2 \u2013 Violent reaction with water
1 \u2013 Unsafe if heated, not violent
0 \u2013 Not reactive with water.<\/p>\n<\/div>\n<\/div>\n\n\n\n

\n
\n

Blue background = health hazard<\/h4>\n<\/div>\n\n\n\n
\n

4 \u2013 Deadly
3 \u2013 Extreme danger
2 \u2013 Hazardous
1- Slightly hazardous
0 \u2013 Normal material<\/p>\n<\/div>\n<\/div>\n\n\n\n

\n
\n

White background = reactivity<\/h4>\n<\/div>\n\n\n\n
\n

Oxidizer : OX
Acid: ACID
Alkali: ALK
Corrosive: CORR
Use No Water: W<\/p>\n<\/div>\n<\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"

Labeling is required by law. The container must provide the full name of the substance with no abbreviations. In addition, hazardous chemicals must also contain basic warning information. The basic warning information is the following: The chemical lab group the waste originated from, full name of the chemical waste (no abbreviations), percentage of chemical waste […]<\/p>\n","protected":false},"author":3,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":"","_links_to":"","_links_to_target":""},"class_list":["post-81","page","type-page","status-publish","hentry"],"yoast_head":"\nMaterials labeling and signage | Environmental Health and Safety | Clark University<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/www.clarku.edu\/environmental-health-and-safety\/materials-labeling-and-signage\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Materials labeling and signage\" \/>\n<meta property=\"og:description\" content=\"Labeling is required by law. 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