Update on the Dangerous Goods Classification

This article about the dangerous goods classification intends to provide guidance on working entities in determining the number of hazardous substances (DSs) or what we call dangerous goods that are required by the Safety and Health Regulations of Workplaces (one of the major hazard facilities).

The amounts shall be registered in the Major Hazard Installation (MHI) Assessment Form and submitted during the MHI registration application or renewal. 

What is MHI? What is it?

The MHI is a requirement specified in the WSH (MHI) Regulations. In order for a workplace to be designated as an MHI, two conditions must be met: 

(i) the quality of the activities at work, and 

(ii) the inventory levels of hazardous (actual or likely to occur) substances that meet or exceed the threshold.

Condition (i) – the nature of work activities 

Firstly, the work activities for the premise involve the production, manufacture, or storage of bulk by trade or to gain any DS specified in the First Schedule.

For processing, this refers to any use of DS during the primary working process e.g., at a chemical plant, its reactant, carrier, diluent, catalyst, additives, heating/cooling medium, etc. Typical workplaces that comply with this requirement include oil refineries, petrochemical processing plants, chlorine stores, oil terminals, big chemical stores, pharmaceutical stores, and wafer production plants for processing.

Condition (ii) – Quantities of dangerous substances 

At least one of the following two conditions must be met to fulfill the second condition of quantities of hazardous substances: 

(a) quantities of the actual dangerous substances that are present or likely to be present are equal to or greater than the specified threshold quantities; or 

(b) the amount for each dangerous substance present that is likely to exceed its prescribed threshold quantities.

The guide helps focus on the principles and methods for defining and quantifying the dangerous substances at the workplace.

(i) the inventory of all on-site chemical inventories 

(ii) the forecast for the next five years of inventory of dangerous substances, if applicable 

(iii) Safety Data Sheets (SDS) of the chemicals 

(vi) Other existing licenses with regards to the use, importation, transport or storage of chemicals applied with the authorities, e.g.

1. Petroleum & Flammable Materials (P&FM) Licence administered by SCDF
2. Hazardous Substance (HS) Permit for storage administered by NEA
3. Arms & Explosives Licence administered by SPF
4. Chemical Weapons Convention (CWC) Licence administered by Singapore Customs  

Concept of Dangerous Substance (DS)

1. Authorization for weapons and explosives provided by SPF 
2. The license under the Singapore Customs Concept of Dangerous Substances (DS) Chemical Weapons Convention (CWC) 

The concept of DS was adopted under the Seveso III Guidelines used in European countries. In the Singapore context, the word “hazardous substance” refers to any substance, mixture or preparation–

(a) referred to in Part 1 of the First Schedule of the Regulations to the WSH (MHI); or (b) refers to any substance, mixture, or preparation referred to in Part 2 of the First Schedule of the Regulations on the WSH (MHI). 

This rule means that DSs should include: 

(i) variation in inventory that can occur because of the fluctuations in seasonal demands and activities of businesses or DSs sometimes but not at times; and 

(ii) those that can be generated during the loss of control over an industrial chemical process (i.e., intermediate products, intermediate products or by-products). Common examples of such DS include dioxin, hydrogen sulfide, phosgene, etc. Do not confuse such substances, and MHI must continue to comply with the legal requirements regulating hazardous substances or dangerous goods classification in the relevant legislation.