Un Hazard Class

Do NOT wash away into sewer. Sweep spilled substance into containers if appropriate, moisten first to prevent dusting. Carefully collect remainder, then remove to safe place. Personal protection P3 filter respirator for toxic particles. Unbreakable packaging put breakable packaging into closed unbreakable container. Do not transport with food and feedstuffs. EU Classification Symbol T, N R 21-25-36/38-48/23/25-50/53 S 1/2-35-36/37/39-45-60-61 Note A, 1 UN Classification UN Hazard Class 6.1 ... 

Collect leaking liquid In sealable containers. Sweep spilled substance into containers if appropriate, moisten first to prevent dusting. Carefully collect remainder, then remove to safe place (extra personal protection self-contained breathing apparatus). UN Classification UN Hazard Class 6.1 ... 

Pyrophoric and other spontaneously combustible substances will generally be identified as such on their product literature, material safety data sheets (MSDSs), or International Chemical Safety Cards (ICSCs). If transported, these substances should be identified as DOT/UN Hazard Class 4.2 materials for shipping purposes and labeled as spontaneously combustible. For pyrophoric substances, the NFPA 704 diamond for container or vessel labeling has a red (top) quadrant with a rating of 4, indicating the highest severity of flammability hazard (NFPA 704, 2001). Note that pyrophoric materials often exhibit one or more other reactivity hazards as well, such as water reactivity. 

Substances that are water-reactive will nearly always be identified as such on their MSDSs or ICSCs. They may be identified as DOT/UN Hazard Class 4.3 materials for shipping purposes and labeled as dangerous when wet. However, some water-reactive materials are classified otherwise. Acetic anhydride is designated Class 8 it may also be identified as a combustible liquid. 

S (l/2-)7/9-16-36/37-38-45 UN Hazard Class 6.1 UN Subsidiary Risks 3 UN Packing Group I Marine pollutant. 

Organic peroxides, included in the same general DOT/UN Hazard Class (Class 5) as oxidizers, are considered here to be self-reactive materials, so are addressed with Question 11 below. 

Is any substance identified as spontaneously combustible YES Sodium hydrosulfite is DOT/UN Hazard Class 4.2, Spontaneously Combustible Material finely divided aluminum powder is pyrophoric without oxide coating... 

UN Hazard Classes and Divisions — The hazard class of a material is indicated either by its class (or division) number, or its class name. For a placard corresponding to the primary hazard class of a material, the hazard class or division number must be displayed in the lower comer of the placard. The UN (United Nations) hazard classes are as follows ... 

Warning labels aid in the identification of chemical hazards during shipment. Under regulations of the DOT, chemicals that are transported in the United States must carry labels based on the UN classification. DOT placards or labels are diamond shaped with a digit imprinted on the bottom corner that identifies the UN hazard class (1 to 9). The hazard is identified more specifically in printed words placed along the horizontal axis of the diamond. Color coding and a pictorial art description of the hazard supplement the identification of hazardous material on the label the artwork appears in the top corner of the diamond (Figure 1-6, A). 

Chemicals regulated by the DOT are listed in the hazardous materials tables in 49 CFR 100-199. This book will use the nine DOT/UN hazard classes to group hazardous materials. The hazard classes are shown in Figure 1.6. 

Sodium is a UN Hazard Class-4 hazardous chemical because of its reactivity with water and halogenated chemicals. Sodium metal is usually shipped in nonreusable 5-kg to 200-kg drums, while jacketed drums with 400-kg capacity, isotanks, and 50-tonne wagons are also used. 

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