EHS stack 1: Safety in design

These flashcards cover key concepts from the lecture on Environment, Health, and Safety.

Name two international regulatory bodies and their functions in process safety.

1. Health and Safety Executive (HSE, UK): Sets standards used worldwide for health, safety, and environment. 

2. National Offshore Petroleum Safety and Environmental Management Authority (NOPSEMA, Australia): Provides guidance and regulatory oversight for offshore oil and gas safety cases.

What is the purpose of the Health and Safety Executive (HSE) in the UK?

To provide guidance and support for 'Safety Cases' used in offshore oil and gas facilities.

What is the function of the Bureau of Safety and Environmental Enforcement (BSEE) in the US? 

BSEE is responsible for offshore safety in the US, managing the Safety and Environmental Management Systems (SEMS) program, which is based on API RP 75 and similar to OSHA's PSM rule.

What is the main mandate of the Environmental Protection Agency (EPA) in the US?

The EPA's broad mandate is environmental protection, including the Risk Management Program (RMP) for process industries, which is similar to OSHA's PSM standard.

What is the mission of the Department of Transportation Federal Railroad Administration (FRA)?

The FRA's mission is to enable the safe, reliable, and efficient movement of people and goods, including the transportation of hazardous and flammable chemicals by rail.

What is the goal of OSHA, and what is one of its most important regulations for process industries? 

OSHA's goal is to assure safe and healthful working conditions by setting and enforcing standards and providing training, outreach, education, and assistance. One key regulation is the PSM standard, 29 CFR §1910.119. (Occupational Safety and Health Administration)

What is the role of the Pipeline and Hazardous Materials Safety Administration (PHMSA)?

PHMSA, part of the Department of Transportation, aims to protect people and the environment by advancing the safe transportation of energy and hazardous materials, focusing on public area pipelines.

Why are industry standards important, and what organizations provide guidance for their development? 

Industry standards reflect collective knowledge and experience, sometimes adopted into law. The International Organization for Standardization (ISO) and ANSI provide guidance for developing and implementing standards.

What are the key principles in the development of ISO standards?

ISO standards are developed based on consensus, considering the views of all interests (manufacturers, users, consumer groups, governments, etc.), and aim for industry-wide, global solutions.

Which two ISO standard groups are particularly relevant to process industries? 

ISO 9000 (Quality Management Systems) and ISO 14000 (Environmental Management Systems) are especially relevant to process industries.

What are the main steps in implementing and managing ISO 9000/14000 standards?

1. Document what will be done. 

2. Train everyone to follow the standards and start program activities. 

3. Implement an audit program. 

4. Suggest improvements for current operations.

 What is the difference in timeline focus between environmental, health, and safety elements in HSE?

Environmental/sustainability covers all life forms over years or decades, health covers public and workers over months to years, and safety focuses on workers in the short term or instantaneously.

What is the purpose of a process safety program in industrial facilities? 

A process safety program is required by law to ensure safe, clean, and profitable operations, and is foundational even for companies not legally required to have one.

List five elements of a Process Safety Management (PSM) program. 

1. Process Safety Culture 

2. Compliance 

3. Competence 

4. Workforce Involvement 

5. Hazard Identification and Risk Management

What are the two broad strategies for managing safety and risk? 

1. Rule-based and prescriptive (used in most regulations and standards) 

2. Risk-based methodology (focuses on hazards, consequences, and likelihood)

 What are the three components of risk in industrial settings?

1. A hazard (e.g., leak from a storage tank) 

2. The consequences of the hazard (safety, environmental, economic) 

3. The likelihood of occurrence of the hazard

What is the formula for risk in risk management, and what does the exponent 'n' represent?

Risk = Consequenceⁿ × Predicted frequency.

The exponent 'n' shows that rare/high-consequence events have a greater impact than frequent/low-consequence events.

Why can risk never be zero in industrial facilities? 

Hazards are always present, their consequences are always undesirable, and the likelihood of occurrence is always finite, making zero risk impossible.

What are the main approaches to reducing risk in industrial settings? 

1. Remove the hazard or people from the scene. 

2. Reduce the consequence of the event. 

3. Reduce the likelihood or predicted frequency if the first two are not possible.

What is a risk matrix and what does it show? 

A risk matrix is a tool that displays the relationship between the likelihood and consequence of a hazardous event, helping to assess and prioritize risks.

What factors influence the choice of construction materials in process facilities?

Factors include temperature, pressure, ability to handle external fire, corrosion/erosion susceptibility, strength, and embrittlement.

What are the three components of the fire triangle? 

Fuel, air (oxygen), and a source of ignition.

Why must fuel be in vapor form to burn?

Liquids and solids do not burn directly; fire generates flammable vapors at their surface, and it is those vapors that actually burn.

How is the frequency of a fire or explosion event calculated in a fault tree analysis?

By multiplying the frequency of the initiating event (fuel leak) by the probabilities of contingent events (air present and ignition source present).

What is the flammable range, and how is it defined?

The flammable range is the concentration range of fuel vapor in air where combustion can occur, defined by the Lower Flammable Limit (LFL) and Upper Flammable Limit (UFL).

What is the flash point of a substance? 

The flash point is the temperature at which a vapor within its flammable range can be ignited by an ignition source. Below this temperature, the vapor mixture will not burn even if a source of ignition exists.

How does OSHA define a flammable liquid? 

A flammable liquid is any liquid having a flashpoint at or below 199.4 °F (93 °C).

What is the primary factor in determining the fire hazard of a flammable liquid? 

Vapor generation is the primary factor, since it is the vapor, not the liquid itself, that burns.

How are flammable liquids categorized according to OSHA?

Flammable liquids are divided into four categories based on flashpoint and boiling point, with Category 1 being the most flammable and Category 4 the least.

What are some common sources of ignition in process facilities? 

Flames, hot surfaces, electrical equipment, wiring, sparks from tools, electrostatic charges, lightning, and iron sulfide are common ignition sources.

List two ways to eliminate ignition sources in process facilities. 

1. Replace fired heaters with electrical heaters or waste heat recovery units. 

2. Eliminate rotating machinery where possible.

What is the recommended ground resistance for lightning arrestors in fire protection systems? 

Ground resistance for arrestors should generally be no more than 5 ohm (Ω), and where practical, no more than 2 Ω.

What are the three major criteria for defining a hazardous area? 

1. The type of hazard 

2. The likelihood of the hazard being present 

3. The ignition temperature of the hazardous material

 What is a Class I hazardous area according to the NEC?

A Class I area is hazardous because flammable gases or vapors are present in the air in quantities sufficient to produce explosive or ignitable mixtures.

(National Electrical Code)

What is the difference between Division 1 and Division 2 in NEC classifications? 

Division 1: Hazardous material is present during normal conditions. 

Division 2: Hazardous material is present only in abnormal conditions, such as equipment failure.

What materials are included in NEC Group D? 

Group D includes gasoline, acetone, ammonia, benzene, butane, ethanol, hexane, methanol, methane, vinyl chloride, natural gas, naphtha, propane, or gases of equivalent hazard.

How does the IEC (International Electrotechnical Commission) code classify hazardous zones?

Zone 1: Explosive atmosphere is continuously present. 

Zone 2: Explosive atmosphere is often present. 

Zone 3: Explosive atmosphere may accidentally be present. 

Unclassified: No significant hazard.

What is the best form of fire protection in industrial settings? 

Passive fire protection, such as maintaining sufficient separation between equipment and using fire-protection barriers or walls, is the best form.

Why is fireproofing insulation applied to structural steel in process facilities?

Unprotected steel loses strength rapidly at high temperatures; fireproofing insulation helps maintain structural integrity during a fire.

 List three items that should be considered for fireproofing protection. 

1. Fired equipment handling flammable materials 

2. Rotating or reciprocating mechanical equipment handling flammable materials 

3. Drums, exchangers, columns, tanks, and vessels containing flammable materials

When is fireproofing generally not warranted? 

Fireproofing is not warranted when the cost of fireproofing exceeds the potential risk, failure would not cause significant damage, or the structure is far from fire sources.

 What are typical temperature limits for fireproofing protection?

Structural steel: below 540°C 

Pressurized vessels: 250°-300°C 

Cabling: 100°-150°C 

Vessel skirts/pipe bridges: below 540°C 

Electrical circuits: below 140°C

How long does fireproofing insulation typically provide protection?

Typically, fireproofing insulation provides 30 minutes of protection, with longer durations (up to 3 hours onshore, 2 hours offshore) possible depending on requirements.

What properties should effective fireproofing materials possess? 

Low thermal conductivity, low density, incombustibility, good bonding strength, resistance to weathering and thermal shock, hardness, good vapor permeability, and ability to withstand direct flame up to 2000°C.

Why is fireproofing insulation used in cryogenic systems? 

To prevent embrittlement and fractural failure of structures due to rapid cooling from released liquefied gases, using combined cold insulation/fireproofing systems. Cryogenic systems handle extremely cold temperatures (e.g., liquid oxygen, nitrogen, etc.)