Frequently Asked Questions
Clear answers to the questions we hear most often about process safety, our services, standards and working with Nexis PS across Africa.
Process Safety Basics
Occupational safety (OHS) focuses on preventing injuries and illnesses to individual workers - slips, falls, manual handling, PPE, etc.
Process safety focuses on preventing major accidents caused by the loss of containment of hazardous materials or energy - fires, explosions, toxic releases and structural failures. These events can injure or kill many people simultaneously, and their consequences can extend beyond the facility boundary.
In high-hazard industries (chemical, energy, mining, food processing), both disciplines are essential - but process safety addresses the catastrophic risk profile that OHS alone does not.
A Hazard and Operability (HAZOP) study is a structured, systematic examination of a process design - typically using Piping and Instrumentation Diagrams (P&IDs) - to identify potential hazards and operability problems.
HAZOP studies are conducted:
- During design of new plants or modifications (HAZOP is a standard requirement under most major project standards and most insurer requirements)
- For existing plants where a formal risk review hasn't been done
- Before recommissioning after significant changes
- As part of periodic safety audits
In South Africa, the OHS Act's Major Hazard Installation (MHI) regulations effectively require HAZOP-level risk assessment of qualifying facilities. Insurance requirements and lender conditions often specify HAZOP for high-hazard projects.
Process Safety Management (PSM) is a systematic framework that manages the integrity of operating systems and processes that handle hazardous substances and energy.
The CCPS (Centre for Chemical Process Safety) defines 14 PSM elements including:
- Process Safety Information (PSI)
- Process Hazard Analysis (PHA / HAZOP)
- Management of Change (MOC)
- Pre-Startup Safety Review (PSSR)
- Mechanical Integrity
- Emergency Planning and Response
- Incident Investigation
A well-implemented PSM programme systematically reduces the risk of major process incidents. Nexis PS helps clients develop, implement and audit PSM programmes aligned to their regulatory obligations and risk profile.
We work across a range of international and South African standards depending on the scope of work:
- IEC 61511 - Functional Safety / SIL for Process Sector
- IEC 60079 series - Explosive Atmospheres
- SANS 10108 - Hazardous Area Classification (SA)
- ISO 45001:2018 - OHS Management Systems
- ISO 22000:2018 - Food Safety Management Systems
- ISO 9001:2015 - Quality Management Systems
- IEC 61882 - HAZOP Studies Guide
- NFPA 652 / 654 - Combustible Dust
- ISO 13849 / IEC 62061 - Machine Safety
- CCPS Process Safety Management framework
We also maintain awareness of the South African OHS Act, Mines Health and Safety Act, NEMA and applicable SANS standards.
Our Services
Our core service areas are:
- HAZOP, LOPA and risk studies
- SIL Determination and Verification (IEC 61511)
- Hazardous Area Classification (ATEX / IECEx / SANS 10108)
- Combustible Dust Hazard Analysis (DHA)
- Process Safety Management (PSM) programme development and auditing
- ISO Management Systems (ISO 45001, ISO 22000, ISO 9001)
- Machine Safety (ISO 13849 / IEC 62061)
- Process Safety Training and capacity building
We work with clients from initial scoping through to study completion, report delivery and implementation support.
Yes - we have successfully facilitated remote HAZOP studies using video-conferencing platforms with shared P&ID review tools. Remote HAZOP requires good process documentation (P&IDs, PFDs, operating procedures), a well-prepared client team and structured session management.
For many documentation-based studies (LOPA, SIL Determination review, gap assessments, management system development), remote delivery is standard. On-site presence is most valuable for hazardous area classification surveys, machine safety inspections, and audit-based work.
Duration depends on plant complexity and number of process nodes:
- Simple facility (2-4 nodes): 1-2 workshop days
- Medium facility (5-15 nodes): 3-5 workshop days
- Complex plant (20+ nodes): 7-15+ workshop days
In addition to workshops, preparation (P&ID review, node definition, team briefing) typically takes 2-4 weeks, and report write-up and review takes 2-4 weeks after workshop completion. Total elapsed time from kick-off to final report is typically 6-12 weeks for a medium-sized project.
Yes. We provide tailored training sessions and workshops on:
- Process Safety Fundamentals (1-day to 2-day)
- HAZOP Facilitation Methods
- Hazardous Area Classification (ATEX / IECEx)
- Combustible Dust Risk and DHA Approach
- SIL Concepts and IEC 61511 Overview
- ISO 45001 Internal Auditor (IRCA-aligned)
- ISO 22000 Food Safety Implementation
Training is developed to match your industry, site type and team knowledge level. We can deliver on-site, at our offices, or remotely. Contact us for a tailored training proposal.
ATEX & Explosive Atmospheres
Hazardous area classification (HAC) is the process of identifying locations where flammable gases, vapours, mists or combustible dusts may be present in sufficient quantities to create an explosion risk - and then classifying those locations into Zones based on the likelihood and duration of the hazardous atmosphere.
- Zone 0 / 20: Continuously present
- Zone 1 / 21: Likely in normal operation
- Zone 2 / 22: Unlikely except in abnormal conditions
Once Zones are defined, only electrical and mechanical equipment certified and marked for use in that Zone may be installed. In South Africa, SANS 10108 governs HAC. IEC 60079-10-1 (gases) and IEC 60079-10-2 (dust) are the primary technical standards. ATEX and IECEx are certification/marking systems for equipment.
In South Africa, the OHS Act (Electrical Machinery Regulations and Hazardous Substances Act) effectively requires that electrical and instrumentation equipment installed in classified (Zone 0, 1, 2, 20, 21, 22) locations must be suitable for use in those locations.
ATEX certification (Europe) or IECEx certification (internationally) provides the recognised mechanism for demonstrating equipment suitability. In practice, most major South African and African industrial facilities accept ATEX or IECEx-certified equipment as meeting the regulatory requirement for Ex-rated equipment in classified areas.
Hazardous area classifications should be reviewed:
- Whenever process changes (new equipment, chemical changes, layout modifications)
- Following any explosion, fire or near-miss incident in a classified area
- Periodically - best practice recommends every 3-5 years as a minimum
- Before significant maintenance, construction or hot-work activities in or near classified zones
Outdated or incorrect HAC documents are a significant liability - both from a safety and insurance standpoint. Nexis PS regularly encounters facilities where original HAC drawings are decades old and no longer reflect the actual site layout or equipment.
ISO Management Systems
Nexis PS implements and prepares management systems for certification - but certification itself is issued by an accredited third-party Certification Body (CB) such as Bureau Veritas, SGS, DEKRA, TÜV Rheinland, LRQA or similar.
Our role is to:
- Conduct gap assessments against the standard
- Design and document your management system
- Develop procedures, objectives and performance measurement frameworks
- Train your team to operate and maintain the system
- Prepare you for Stage 1 and Stage 2 certification audits by the CB
Most of our clients achieve certification within 6-12 months of engaging us, depending on their starting point.
OHSAS 18001 was the previous international standard for OHS management systems, withdrawn and replaced by ISO 45001:2018.
ISO 45001 uses the Annex SL high-level structure common to all modern ISO management standards (like ISO 9001 and ISO 14001), making integration easier. ISO 45001 places greater emphasis on:
- Worker participation and consultation
- Context of the organisation and external/internal issues
- Leadership commitment
- Risk-based thinking and opportunities
All OHSAS 18001 certifications have expired. If your facility still references OHSAS 18001, you are operating on an obsolete standard and should upgrade to ISO 45001:2018. Nexis PS can manage that transition.
Typical implementation timelines:
- Greenfield (no existing system): 9-18 months to certification-ready
- Existing OHS system with documentation: 4-9 months
- Transition from OHSAS 18001: 3-6 months
Timelines depend on organisation size, complexity, management commitment and resource availability. Nexis PS works with your team to set realistic milestones and provides hands-on implementation support throughout.
Working with Nexis PS
Nexis Process Safety is based in Centurion, Gauteng, South Africa. We serve the full South African market and regularly deliver projects across Southern Africa (Botswana, Zimbabwe, Zambia, Mozambique, Namibia) and East and West Africa (Tanzania, Kenya, Ghana, Nigeria and others) by arrangement.
For remote delivery - including HAZOP facilitation, management system development and gap assessments - geographic location is rarely a barrier.
1. Initial Contact - you submit an enquiry; we respond within 1 business day.
2. Scoping Consultation - free 30-60 minute call to understand your site, hazards and project objectives. NDA available.
3. Technical Proposal - a detailed scope of work with deliverables, timeline and fee proposal (typically within 5 business days).
4. Kick-Off - project team introduced, schedule agreed, information request issued.
5. Delivery - studies, workshops, documentation developed per agreed scope.
6. Review & Finalisation - draft deliverables reviewed with client, comments incorporated.
7. Final Report - issued in agreed format. Post-project support discussed.
Absolutely. Many of our most effective engagements are collabourative - we provide the specialist technical expertise (HAZOP facilitation, SIL determination, HAC classification) while your in-house HSE and engineering team provide site knowledge, process expertise and management system ownership.
We can also provide mentoring and skills transfer to develop your team's competence in process safety methodology over time.
Study costs vary significantly based on scope, complexity and deliverable requirements. As a general guide:
- Small HAZOP (1-2 days workshop): from R25,000
- Medium HAZOP (3-5 days workshop): from R60,000
- Full HAZOP + LOPA study (medium plant): from R120,000
- ISO 45001 implementation (medium company): from R80,000
- Hazardous area classification study: from R30,000
This is guidance only - every project is priced individually. Contact us for a no-obligation, fixed-fee proposal for your specific scope.
Still Have Questions About Process Safety?
Our specialists are happy to discuss your specific situation - no sales pressure, no commitment required. Every question we answer helps build a safer African industrial sector.