The ever-changing industrial processes which are becoming more globalised as well as the merging of markets in different economies, led to an increased focus on the health and safety of workers in the industries and the mining sector over the past decades. Occupational exposure limits (OELs) have been used for more than half a century as a risk management tool for the prevention of work-related illnesses which may arise from the exposure to a wide variety of hazardous chemical substances in the working environment. Aim: The aim of this study is to analyse comparatively occupational exposure limits (OELs) of hazardous chemical substances from selected groups contained in the Hazardous Chemical Substance Regulations (HCSR) and the Mine Health and Safety Regulations (MHSR) with those of selected developed countries and organisations. Method: The two lists of OELs from South Africa – HCSR and MHSR – were compared with 11 different developed countries and/or organisations namely: Canada (British Colombia), United Kingdom (Health and Safety Executive, HSE), Australia (National Occupational Health and Safety Commission, NOHSC), New Zealand (Ministry of Business, Innovation and Employment), Japan (Japan Society for Occupational Health, JSOH), Finland (Ministry of Social Affairs and Health), Germany (Deutsche Forschungsgemeinschaft-DFG), Sweden (Swedish Work Environment Authority) and United States of America (American Conference of Governmental Industrial Hygienists, ACGIH, Occupational Safety and Health Administration, OSHA and National Institute for Occupational Safety and Health, NIOSH). The selection of these countries and organisations was done on the basis of their dominance in the literature as well as the availability of the lists containing OELs. The OELs from each country and/or organisation, depending on the nature and characteristics of the said element and/or compound, were categorised into one of four groups, namely: pesticides, metals, dusts and fibres. The geometric means of each country and/or organisation were calculated from the ratios of each list by using the HCSR and MHSR as the denominator respectively. Results: It became evident that South Africa performed poorly when compared to other countries and/or organisations, indicated in this study. OSHA overall had the highest set OELs, in five out of the six comparisons that could be made, thus being less stringent than South Africa’s. Countries and organisations such as Sweden, Japan and Finland have the lowest overall set OELs for the different groups respectively. Conclusion: South African OELs legislated by both the HCSR and MHSR, are overall higher (less stringent) when compared to those of developed countries and/or organisations. The less stringent nature of South African OELs may be attributed to infrequent rate at which they are updated. The failure to incorporate recent scientific knowledge into OELs may impact on the health of workers. South Africa should follow international best practice and increase the frequency at which OELs are updated. Recommendations: The effectiveness of having two sets of OELs within a country; each applicable to its own industry should be investigated. Attention with regards to the groups lacking attention, i.e. fibres and pesticides should be given priority when revised. Although the other groups should not be disregarded. Duplicate OELs identified in the HCSR should be removed. To prevent duplicate OELs from being established it would be prudent to utilise CAS numbers when referring to substances in addition to their common and chemical names, thus this supports the recommendations made in an earlier study. / MSc (Occupational Hygiene), North-West University, Potchefstroom Campus, 2015

The ever-changing industrial processes which are becoming more globalised as well as the merging of markets in different economies, led to an increased focus on the health and safety of workers in the industries and the mining sector over the past decades. Occupational exposure limits (OELs) have been used for more than half a century as a risk management tool for the prevention of work-related illnesses which may arise from the exposure to a wide variety of hazardous chemical substances in the working environment. Aim: The aim of this study is to analyse comparatively occupational exposure limits (OELs) of hazardous chemical substances from selected groups contained in the Hazardous Chemical Substance Regulations (HCSR) and the Mine Health and Safety Regulations (MHSR) with those of selected developed countries and organisations. Method: The two lists of OELs from South Africa – HCSR and MHSR – were compared with 11 different developed countries and/or organisations namely: Canada (British Colombia), United Kingdom (Health and Safety Executive, HSE), Australia (National Occupational Health and Safety Commission, NOHSC), New Zealand (Ministry of Business, Innovation and Employment), Japan (Japan Society for Occupational Health, JSOH), Finland (Ministry of Social Affairs and Health), Germany (Deutsche Forschungsgemeinschaft-DFG), Sweden (Swedish Work Environment Authority) and United States of America (American Conference of Governmental Industrial Hygienists, ACGIH, Occupational Safety and Health Administration, OSHA and National Institute for Occupational Safety and Health, NIOSH). The selection of these countries and organisations was done on the basis of their dominance in the literature as well as the availability of the lists containing OELs. The OELs from each country and/or organisation, depending on the nature and characteristics of the said element and/or compound, were categorised into one of four groups, namely: pesticides, metals, dusts and fibres. The geometric means of each country and/or organisation were calculated from the ratios of each list by using the HCSR and MHSR as the denominator respectively. Results: It became evident that South Africa performed poorly when compared to other countries and/or organisations, indicated in this study. OSHA overall had the highest set OELs, in five out of the six comparisons that could be made, thus being less stringent than South Africa’s. Countries and organisations such as Sweden, Japan and Finland have the lowest overall set OELs for the different groups respectively. Conclusion: South African OELs legislated by both the HCSR and MHSR, are overall higher (less stringent) when compared to those of developed countries and/or organisations. The less stringent nature of South African OELs may be attributed to infrequent rate at which they are updated. The failure to incorporate recent scientific knowledge into OELs may impact on the health of workers. South Africa should follow international best practice and increase the frequency at which OELs are updated. Recommendations: The effectiveness of having two sets of OELs within a country; each applicable to its own industry should be investigated. Attention with regards to the groups lacking attention, i.e. fibres and pesticides should be given priority when revised. Although the other groups should not be disregarded. Duplicate OELs identified in the HCSR should be removed. To prevent duplicate OELs from being established it would be prudent to utilise CAS numbers when referring to substances in addition to their common and chemical names, thus this supports the recommendations made in an earlier study. / MSc (Occupational Hygiene), North-West University, Potchefstroom Campus, 2015

Various hazardous chemical substances are used daily as part of manufacturing and processing. Exposure to these hazardous chemical substances (HCSs) can cause adverse health effects in the exposed workers. Occupational exposure limits (OELs) are used to control exposure to these HCSs and thereby protect workers from the adverse effects that exposure may induce. The aim of this study was to compare South African list of OELs as contained in the Hazardous Chemical Substance Regulations (HCSR) to several developed and developing countries based on two aspects: (1) the number of substances that are selected and regulated by the lists of each country (2) and the overall level of the OELs set by the different countries and jurisdictions. Due to the nature and the large amount of data the study is divided into two parts. The first part is a comparison of South African OELs with nine developed countries and jurisdictions along with the Mine Health and Safety Act Regulation 22.9 (MHSR) of South Africa. The second comparison was conducted between South African and the four developing BRICS countries. BRICS is an acronym for: Brazil, Russia, India, China and South Africa, all are leading developing countries. Substance selection and coverage was compared by analysing the number of overlapping and uniquely regulated OELs that existed between countries. The over-all level of OELs was determined and quantified by using the statistical method, the geometric means of ratios. These ratios were compared in order to establish how the levels of OELs of the South African HCSR compare with the level of the various other countries. Results indicated that there are large and unsystematic differences between the selection of HCSs that are regulated by different countries and jurisdictions. Individual coverage and selection of HCSs between the various developing and developed countries and jurisdictions in the study was inconsistent and dissimilar. A high number of HCSs are regulated by only one of the various countries included in this study. Among the developed countries 20.8% of substances are uniquely regulated, whereas 46% of HCSs are regulated by only one of the various developing countries. According to the geometric means of ratios Occupational Safety and Health Administration (OSHA) is the only jurisdiction in a developed country that has a higher overall level of OELs when compared to South Africa as for the rest of the developed countries they all yielded a lower overall level of OELs. American Conference of Governmental Industrial Hygiene (ACGIH) had the lowest overall level of OELs. When compared with the BRICS countries South Africa had a higher overall level of OELs. The average overall level of OELs differs substantially between the BRICS countries; Russia having the lowest, and Brazil having the highest overall limit when compared relative to South African HCSR. Strong similarities were found between South African HCSR and MHSR indicating national similarity. The South African OELs for HCSs have an overall higher level than the majority of developed and developing countries. Various factors may be responsible for these differences among countries and jurisdictions. These factors include, variations in scientific reasoning, the risk acceptance of the negative impact that various HCSs might induce and the time lags that countries have between updates. Further differences may be explained by the difference in consideration of socio-economical and practical feasibility of an OEL and the predominant industries in a country. / Thesis (MSc (Occupational Hygiene))--North-West University, Potchefstroom Campus, 2013

Various hazardous chemical substances are used daily as part of manufacturing and processing. Exposure to these hazardous chemical substances (HCSs) can cause adverse health effects in the exposed workers. Occupational exposure limits (OELs) are used to control exposure to these HCSs and thereby protect workers from the adverse effects that exposure may induce. The aim of this study was to compare South African list of OELs as contained in the Hazardous Chemical Substance Regulations (HCSR) to several developed and developing countries based on two aspects: (1) the number of substances that are selected and regulated by the lists of each country (2) and the overall level of the OELs set by the different countries and jurisdictions. Due to the nature and the large amount of data the study is divided into two parts. The first part is a comparison of South African OELs with nine developed countries and jurisdictions along with the Mine Health and Safety Act Regulation 22.9 (MHSR) of South Africa. The second comparison was conducted between South African and the four developing BRICS countries. BRICS is an acronym for: Brazil, Russia, India, China and South Africa, all are leading developing countries. Substance selection and coverage was compared by analysing the number of overlapping and uniquely regulated OELs that existed between countries. The over-all level of OELs was determined and quantified by using the statistical method, the geometric means of ratios. These ratios were compared in order to establish how the levels of OELs of the South African HCSR compare with the level of the various other countries. Results indicated that there are large and unsystematic differences between the selection of HCSs that are regulated by different countries and jurisdictions. Individual coverage and selection of HCSs between the various developing and developed countries and jurisdictions in the study was inconsistent and dissimilar. A high number of HCSs are regulated by only one of the various countries included in this study. Among the developed countries 20.8% of substances are uniquely regulated, whereas 46% of HCSs are regulated by only one of the various developing countries. According to the geometric means of ratios Occupational Safety and Health Administration (OSHA) is the only jurisdiction in a developed country that has a higher overall level of OELs when compared to South Africa as for the rest of the developed countries they all yielded a lower overall level of OELs. American Conference of Governmental Industrial Hygiene (ACGIH) had the lowest overall level of OELs. When compared with the BRICS countries South Africa had a higher overall level of OELs. The average overall level of OELs differs substantially between the BRICS countries; Russia having the lowest, and Brazil having the highest overall limit when compared relative to South African HCSR. Strong similarities were found between South African HCSR and MHSR indicating national similarity. The South African OELs for HCSs have an overall higher level than the majority of developed and developing countries. Various factors may be responsible for these differences among countries and jurisdictions. These factors include, variations in scientific reasoning, the risk acceptance of the negative impact that various HCSs might induce and the time lags that countries have between updates. Further differences may be explained by the difference in consideration of socio-economical and practical feasibility of an OEL and the predominant industries in a country. / Thesis (MSc (Occupational Hygiene))--North-West University, Potchefstroom Campus, 2013

This thesis focuses on exacerbating chemicals risk in workplaces under the background of rapid industrialization in developing countries. The overall aim is to investigate the development of regulatory tools which aim at minimizing the health risks from chemical substances in the workplace. The contents of the thesis are divided into three sections: the profile of occupational diseases in China (paper I), occupational exposure limits (paper II and III), and comparison between chemicals regulat ions in Europe and China (paper IV). Paper I presents an analysis of the development of occupational diseases in China between 2000 and 2010. The number of recorded cases of occupational diseases increased rapidly in China during this period and the majority of cases were attributable to dust and other chemicals exposures. Difficulties in diagnosis and inefficient surveillance are major impediments to the proper identification and mitigation of occupational diseases. Migrant workers are extremely vulnerable to occupational hazards. Paper II investigates the state of harmonization of OELs between twenty-five OEL systems in Europe and Asia. The majority of the investigated organizations declare themselves to have been influenced by the American Conference of Governmental Industrial Hygienists (ACGIH), and in many cases this can be empirically confirmed. However, large international differences still exist in substance selection and in the level of OELs among organizations. Paper III explores the setting of risk-based OELs on non-threshold carcinogens. Relatively few agencies set risk-based OELs. Differences exist in policy, both regarding the magnitude of risk considered as tolerable or acceptable and whether a general risk level or case-by-case substance-specific risk levels are determined. In regards to the level of the OELs both differences in science and policy contribute, and it was not possible to determine which has the larger influence. Paper III explores the setting of risk-based OELs on non-threshold carcinogens. Relatively few agencies set risk-based OELs. Differences exist in policy, both regarding the magnitude of risk considered as tolerable or acceptable and whether a general risk level or case-by-case substance-specific risk levels are determined. In regards to the level of the OELs both differences in science and policy contribute, and it was not possible to determine which has the larger influence. Paper IV systematically compares the regulation systems for chemicals in the EU and China in terms of substances covered, requirement on information, risk assessment and risk management. It shows that the European and Chinese chemicals legislations are remarkably similar.The differences are larger in terms of substance coverage and data requirements than in terms of risk assessment and management. Substitution of hazardous substances is driven more by updates of the EU regulatory system than of the Chinese system. / <p>QC 20130830</p>

Occupational exposure limits are known to have different distribution values around the world. In recent years occupational exposure limits were reviewed in Lithuania and other Eastern European countries. The changes in occupational exposure limits should influence the hood flow rate. However even today the projectors continue using the same air flow rate equations that were developed years ago. The engineering methods are no longer compatible with sanitary standards. The major dangers resulting from this approach are the occupational exposure limits exceed allowed quotas in workplace or the energy consumption is harmfully inefficient. It is crucial to compare the treatment of occupational exposure limits among various countries and the different existing methods of calculating exhaust air flow rate. Additionally, it is important to consider the factors that may compromise the reliability of this study. Lithuania's occupational exposure limits are in general lower than in other countries. The ratio of occupational exposure limits is about 1:100 in different countries.Exhaust air flow should be inversely proportional to occupational exposure limits. It was found that volumetric exhaust flow rate have a circular dependence on occupational exposure limits by making comparison among different countries. The purpose of this study is to draw attention to the issue of small countries to use the volumetric exhaust air flow rate equations of big countries (USA, Russia, Germany etc.)... [to full text]

Outputs of dose–response assessments can be used as benchmarks that help to identify the need for risk management measures to reduce population health risks associated with exposure to chemicals. Various approaches can be used to facilitate the incorporation of chemical- or scenario-specific data into dose–response analyses, as a means of replacing or influencing default assumptions and extrapolations. The goal of the first part of this thesis was to examine the evolution of approaches to the incorporation of chemical- and scenario-specific data in dose–response assessments in regulatory settings, and identify contextual factors that serve as barriers and facilitators to the use of approaches. A main focus of the investigation was on physiological modelling, which is the most commonly-used category of approaches enabling extrapolations that depart from default assumptions. Evaluations of the dose–response applications of physiological modelling in the peer-reviewed scientific literature and in regulatory reports were conducted. Similarities between the scientific literature databases and regulatory reports were observed with respect to the evolution of physiological modelling in dose–response assessments, notably related to the timing, quantity, and annual frequency of publications. These similarities indicate that a factor in the low dose–response application of physiological modelling, relative to the overall production of physiological models, is an absence of data. However, variability in adoption of physiological modelling in regulatory dose–response assessments was observed among—and even within—organizations faced with the same data, indicating that other factors influence regulatory uptake of physiological modelling. Analysis of a survey indicated that factors acting as barriers or facilitators to regulatory risk assessors’ incorporation of increasingly data-informed approaches originated in both external and internal contexts. The external context was composed of the regulatory environment, domestic and international alignment, availability of external expertise, background of peer reviewers and stakeholders, availability and accessibility of software and tools, and chemical-dependent factors. The internal context was influenced by problem formulation, time and financial resources, organizational and management support, and training. A conceptual framework demonstrating how these factors impact a risk assessor’s ability to incorporate chemical- and scenario-specific data in dose–response analysis was developed, and subsequently used to provide recommendations on actions that could be taken to increase regulatory adoption of increasingly data-informed approaches. The second part of the thesis focused on the development of a knowledge translation tool designed to assist risk managers in the evaluation of dose–response analyses. The tool was focused on occupational exposure limits (OELs), and provides a guide to occupational hygienists in evaluating the relevance and reliability of individual OELs. When occupational hygienists are faced with multiple varying OELs for a chemical of interest, these evaluations can support the selection of the most appropriate OEL for a given situation. The usefulness of the tool was demonstrated for the selection of OELs for an OEL-rich compound (n-hexane), an OEL-poor compound (methamphetamine), and one additional compound (manganese). Such a tool can improve occupational hygienists’ understanding of the basis of OELs and the levels of protection afforded by each, which can contribute to more informed risk management decisions.