Regulations - Page 3 of 3

Module 3: Toxicology - Section 6: General Administrative Regulations and the Hazardous Chemical Substances Regulations Revisited

TOX 6.3: HCS Regulations

B) THE REGULATIONS FOR HAZARDOUS CHEMICAL SUBSTANCES (HCSS):

(Regulation No. 5559, August 1995; Government Gazette 16596, vol. 362). (Click on the "Book" Regulations, and then open the "Book" Hazardous Chemical Substances Regulations.)

Aim:

To control health hazards to workers arising from exposures to potentially hazardous chemical agents/substances;
HCS definition: any toxic, harmful, corrosive, irritant or asphyxiant substance or a mixture of substances for which an occupational exposure limit is prescribed or a substance that can be shown to be harmful to health.

Scope:

All employers, or self-employed person carrying out work at a workplace;
Excludes: workers exposed to biological and radioactive agents, working on the mines;
Superseded by Asbestos and Lead regulations.

INFORMATION AND TRAINING: Employer's duty to train and the worker's right to know:

Obligation on employer to provide training on:

contents and scope of the regulations;
possible sources of exposure;
potential hazards to health and to reproductive capabilities (male and female);
protective measures, including PPE, hygiene, engineering controls, work practices, etc.;
necessity of environmental monitoring and medical surveillance;
emergency procedures.

Includes those transporting HCSs (eg. drivers).

Responsibilities on both employer to provide, and worker to accept training.

Obligation on workers:

Places obligation on exposed worker to obey lawful instructions relating to:

control of exposures;
wearing PPE;
medical surveillance and environmental monitoring
hygiene measures;
training and information.

EXPOSURE ASSESSMENT:

Introduces mandatory Risk Assessment process for Employers. Have to identify:

the HCS to which employees potentially exposed;
possible health hazards associated with the process;
in what physical form and where HCS likely to be present;
routes of exposure;
nature of the work process and the controls present.

Risk Assessment must be done in consultation with health and safety reps or committee.

Repeat at least every 2 years, or more frequently if change in process or inputs.

Triggers both environmental monitoring and medical surveillance.

AIR MONITORING:

Follows from Risk Assessment;
Must be done by "Approved Inspection Authority" or equivalent;
Must follow NIOSH sampling method (OESSM): personal sampling;
In consultation with the safety reps or committee;
Frequency:
12 months for HCS with control-OEL (Table 1 of HCS Regulations. - Open "Book" Regulations, "Book" Hazardous Chemical Substances Regulations, then "Book" Annexure 1 and see "Occupational Exposure Limits - Control Limits" page )
25 months for HCS with recommended-OEL (Table 2 of HCS Regulations. - Open "Book" Regulations, "Book" Hazardous Chemical Substances Regulations, then "Book" Annexure 1 and see "Occupational Exposure Limits - Recommended Limits" page);
If OELs exceeded, prompts remedial action: control measures, PPE, respirator zone.

RESPIRATOR ZONE:

Where not possible to reduce environmental exposure below recommended OEL, can reduce personal exposures by using respiratory PPE. Leads to establishing a Respirator Zone.
Demarcated as such, strict controls: PPE, no food, smoking etc.

MEDICAL SURVEILLANCE:

Follows from Risk Assessment.

Prompted if:

Exposure to substances with known biological exposure indices (Table 3 of HCS Regulations. - open "Book" Regulations, "Book" Hazardous Chemical Substances Regulations, then "Book" Annexure 1 and see "Biological Exposure Indices" page);
Substance not listed but known to be a health hazard and can be monitored.
Recommendation of occupational health practitioner.

Includes:

initial examination and history (within 15 days of employment);
appropriate clinical assessment including special tests;
follow up at set intervals (at least 2 yearly).

Practitioner can remove worker from exposure based on medical monitoring results (declare worker unfit to work).

Forms of medical surveillance:

Biological monitoring: measures the extent of absorption of HCS into the body eg. Blood lead, urinary arsenic;
Biological effect monitoring: measures the intensity of biochemical or physical damage due to exposure eg. Red cell cholinesterase;
Medical screening: detects any adverse health effects of HCS on the worker eg. Lung function test for asthma.

Biological Exposure Indices (Table 3 of HCS Regulations):

Reference values for guidance in the evaluation of potential health hazards;
Indicates level of HCS (or metabolite) detectable from a specimen of a healthy worker exposed to a HCS to the same extent as a worker with inhalation exposure to an OEL-TWA;
Apply to 8-hr exposure 5 days a week;
If measurements persistently exceed the BEI, the cause must be investigated and proper action taken;
Are NOT intended for use as a measure of adverse effects or for diagnosis of an occupational illness;
See Table 3 of HCS Regulations: Meaning of Notations:
A : identifiable population may have increased susceptibility to HCS
B : background (non-occupational sources) levels are included in the BEI
C : non-specific (but better correlate to exposure than specific tests)
D : quantitative interpretation of measured value is ambiguous.

RECORDS AND CONFIDENTIALITY:

all records of medical, environmental monitoring and risk assessments kept;
records kept for at least 30 years;
transfer of records to regional DOL when workplace closes down;
confidentiality maintained.

CONTROL OF HCSS:

Establishes hierarchy of control measures - PPE is a last resort:

HIERARCHY OF CONTROLS SPECIFIED IN HAZARDOUS CHEMICAL SUBSTANCES REGULATIONS:

ADMINISTRATIVE CONTROLS:

Substitute.
Limit amount used.
Limit number of employees exposed.
Limit period of exposure.

ENGINEERING CONTROLS:

Enclose, automate or separate process.
Install local extraction ventilation.
Use wet methods.

WORK PROCEDURES:

Safe handling and disposal.
Maintain equipment.
Clean working areas.
Take early corrective action.

IF CONTROL IS NOT REASONABLY PRACTICABLE BY THE ABOVE METHODS:

PERSONAL PROTECTIVE EQUIPMENT AND CLOTHING:

Appropriate to hazard.
Employees trained and supervised in use.
Careful maintenance, storage, cleaning and disposal.
Washing facilities, dual lockers and change rooms.

(Section 12 deals with adequacy of control equipment and need for audit of control measures every 25 months by an approved inspection authority).

Two types of HCSs:

Those for which level is a health-based limit = Recommended OEL (R-OEL): Table 2 of HCS Regulations;
Those for which health-based limits moderated by considerations of practicability = Control OEL (C-OEL): Table 1 of HCS Regulations.

For substances with Recommended OELs (R-OELs), employer must aim to achieve levels below OEL as far as possible. Temporary excursions can be tolerated if without significant risk of exposure and does not signify failure of control mechanisms.

For substances with Control OELs (C-OELs), employer HAS to keep levels below OEL. If cannot do so by engineering controls, etc, can declare a Respirator Zone and use respiratory PPE to protect workers (last resort). No excursions tolerated due to presence of residual risk. Usually for known carcinogens and where no threshold of effect identified.

STEL (Short-term exposure limit) vs TWA (time-weighted average):

To differentiate between acute and chronic effects of HCSs:

TWA: The long-term (8-hour) time weighted average exposure limit is intended to control effects by restricting the total intake by inhalation over one or more workshifts.
STEL: Short-term exposure limits (usually 15 minute) apply to HCS, which produce effects with brief single or repeated exposures. If not STEL is specified, rule of thumb is three times the long-term limit.

Dusts:

Not all dusts have been assigned an exposure limit. In such cases personal exposure limits assigned for:

inhalable dusts: 10 mg/m³
respirable dusts: 5 mg/m³

Skin:

For certain substances (lipid soluble), dermal route is a more significant route of absorption eg. phenol, aniline, certain pesticides;
Denoted as Sk in Table 1 and Table 2 of HCS Regulations;
Biological monitoring may be more useful in such cases.

Sensitizers:

Certain HCS may cause sensitization in susceptible individuals and cause health effects after very minute concentrations of the HCS eg. isocyanates;
May be through respiratory or dermal route;
Result typically in asthma, rhinitis, extrinsic allergic alveolitis, allergic contact dermatitis;
Denoted as Sen in Table 1 and Table 2 of HCS Regulations;
Activities associated with short-term peak concentrations may be more important.

Mixed exposures:

Majority of exposure limits relate to single compounds;

Effects may be independent, additive or synergistic

For additive effects exposure limit defined as: C₁/L₁ + C₂/L₂ + C₃/L₃ + ...< 1
(C: TWA concentration for a specific HCS, L: exposure limit for that substance).

SUMMARY OF THE ASSESSMENT CYCLE:

Timetable of Actions Required by Hazardous Chemical Substances Regulations:

BASELINE		THEREAFTER
1. Exposure risk assessment	Immediate ¹	2-yearly
2. Air monitoring ^2, 3 Control limit substances Recommended limit substances	Immediate Immediate	Annual 2-yearly
3. Review of control measures by approved inspection authority	Immediate	2-yearly
5. Medical surveillance ²	Immediate	2-yearly ⁵
Notes: 1. And at change in use or breakdown of controls. 2. Contingent on findings of exposure assessment. 3. Carried out or verified by an Approved Inspection Authority. 5. Or otherwise at the discretion of the occupational medicine practitioner.

PERSONAL PROTECTIVE EQUIPMENT (PPE):

PPE is clearly last resort after engineering, administrative and other controls. Obligation placed on employers to:

provide respiratory and skin PPE as required;
ensure PPE in good working order and well maintained;
accompanied by training of workers;
supported by adequate storage, cleaning and changing facilities.

(Section 5 places obligation on worker to use the PPE).

OTHER: PROHIBITIONS, LABELLING OF HCSs:

Smaller section of the Regulations deal with specific prohibitions (ban use of compress air, control of smoking and eating by workers, etc.). Labeling, packaging and transport of HCS dealt with by referring to SABS codes. Environmental emissions and disposal of HCSs in terms of environmental legislation.

ISSUES AND PROBLEMS:

No statutory protection against job loss on medical grounds - left to general labour legislation and section 26(2) of OHSA, which prevents victimisation.
Does not address mixtures of HCSs well. Assumes either additive or no interaction. Schedules do not list whole formulation.
Not well suited to HCS whose main route of absorption is dermal. Relies on air levels. Not suited for working in an open environment.
Not explicit on Risk Assessment process.
Confusion around definition of occupational health practitioner.
Shortage of skills to provide sufficient "approved inspection authorities".
Shortage of enforcement personnel.

Postgraduate Diploma in Occupational Health (DOH) - Modules 3: Occupational Medicine & Toxicology (Basic) by Profs Mohamed Jeebhay and Rodney Ehrlich, Health Sciences UCT is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.5 South Africa License. Major contributors: Mohamed Jeebhay, Rodney Ehrlich, Jonny Myers, Leslie London, Sophie Kisting, Rajen Naidoo, Saloshni Naidoo. Source available from here. For any updates to the material, or more permissions beyond the scope of this license, please email healthoer@uct.ac.za or visit www.healthedu.uct.ac.za. Last updated Jan 2007.
Disclaimer note: Some resources and descriptions may be out-dated. For suggested updates and feedback, please contact healthoer@uct.ac.za.