International Archives of Occupational and Environmental Health, 2002
To co-ordinate the work of the main European research teams in the field of thermal factors in or... more To co-ordinate the work of the main European research teams in the field of thermal factors in order to develop and improve significantly the methods presently available for assessing the risks of heat disorders encountered during work in hot conditions. Each item from the required sweat rate model was reviewed on the basis of the most recent literature. A database with 1,113 laboratory and field experiments, covering the whole range of hot working conditions, was assembled and used for the validation. Influence of clothing ensemble on heat exchange: methods and formulas were developed that take into account the dynamic effects associated with forced convection and the pumping effect associated with body movements and exercise. Prediction of the average skin temperature: the model used in the required sweat rate standard ISO 7933 was extended to cover more severe conditions with high radiation and high humidity and different clothing and take into account the rectal temperature for the prediction of the skin temperature. Criteria for estimating acceptable exposure times in hot work environments: criteria were reviewed and updated concerning the maximum increase in core temperature and the acceptable water loss, for acclimatised and nonacclimatised subjects. These limits are intended to protect 95% of the population. Measuring strategy: a strategy was developed to assess the risks in any working situation with varying conditions of climate, metabolic rate or clothing. A detailed methodology was developed in three stages: an "observation" method for the recognition of the conditions that might lead to thermal stress; an "analysis" method for evaluating the problem and optimising the solutions; and an "expert" method for in-depth analysis of the working situation when needed. the different results were used to prepare a revision of the interpretation procedure proposed in the ISO standard 7933. We validated the modified approaches using the database. This involved the whole range of conditions for which the model was extended, namely conditions with high and low radiation, humidity and air velocity as well as fluctuating conditions. Based on these results, the predicted heat strain model was developed: it is presently proposed as an ISO and CEN standard.
At the request of the European Commission and in the framework of the European Machinery Directiv... more At the request of the European Commission and in the framework of the European Machinery Directive, research was performed in five different laboratories to develop specifications for surface temperature limit values for the short-term accidental touching of the fingertip with cold surfaces. Data were collected in four laboratories with a total of 20 males and 20 females performing a grand total of 1655 exposures. Each touched polished blocks of aluminium, stainless steel, nylon-6 and wood using the distal phalanx of the index finger with a contact force of 1.0, 2.9 and 9.8 N, at surface temperatures from +2 to -40 degrees C for a maximum duration of 120 s. Conditions were selected in order to elicit varying rates of skin cooling upon contact. Contact temperature (TC) of the fingertip was measured over time using a T-type thermocouple. A database obtained from the experiments was collated and analysed to characterize fingertip contact cooling across a range of materials and surface temperatures. The database was subsequently used to develop a predictive model to describe the contact duration required for skin contact temperature to reach the physiological criteria of onset of pain (15 degrees C), onset of numbness (7 degrees C) and onset of frostbite risk (0 degrees C). The data reflect the strong link between the risk of skin damage and the thermal properties of the material touched. For aluminium and steel, skin temperatures of 0 degrees C occurs within 2-6 s at surface temperatures of -15 degrees C. For non-metallic surfaces, onset of numbness occurs within 15-65 s of contact at -35 degrees C and onset of cold pain occurs within 5 s of contact at -20 degrees C. The predictive model subsequently developed was a non-linear exponential expression also reflecting the effects of material thermal properties and initial temperature. This model provides information for the protection of workers against the risk of cold injury by establishing the temperature limits of cold touchable surfaces for a broad range of materials, and it is now proposed as guidance values in a new international standard.
Les “facultés” de travail peuvent être définies comme un équilibre entre les caractéristiques pro... more Les “facultés” de travail peuvent être définies comme un équilibre entre les caractéristiques propres au travailleur-état de santé individuel, ressources personnelles, efficacité, intention de rester, connaissance et capacités-et les exigences liées au travail-charge psychosociale, charge de travail physique, sécurité du travail, exigences de la fonction-auxquelles il doit faire face. En Belgique, la Direction Humanisation du travail du Service Public Fédéral Emploi, Travail et Concertation sociale a entamé une série d’études afin d’approfondir ce concept et créer un questionnaire complet, en français et en néerlandais, appelé le VOW/QFT. Le VOW/QFT a pour but d’étudier comment le travailleur perçoit et vit l’équilibre entre ses propres caractéristiques et les exigences auxquelles il est confronté. L’objectif est de rendre ce questionnaire facile d’accès et d’utilisation pour les professionnels de la santé au travail, leur permettant de disposer d’un outil scientifique et valide pou...
International Archives of Occupational and Environmental Health, 2002
To co-ordinate the work of the main European research teams in the field of thermal factors in or... more To co-ordinate the work of the main European research teams in the field of thermal factors in order to develop and improve significantly the methods presently available for assessing the risks of heat disorders encountered during work in hot conditions. Each item from the required sweat rate model was reviewed on the basis of the most recent literature. A database with 1,113 laboratory and field experiments, covering the whole range of hot working conditions, was assembled and used for the validation. Influence of clothing ensemble on heat exchange: methods and formulas were developed that take into account the dynamic effects associated with forced convection and the pumping effect associated with body movements and exercise. Prediction of the average skin temperature: the model used in the required sweat rate standard ISO 7933 was extended to cover more severe conditions with high radiation and high humidity and different clothing and take into account the rectal temperature for the prediction of the skin temperature. Criteria for estimating acceptable exposure times in hot work environments: criteria were reviewed and updated concerning the maximum increase in core temperature and the acceptable water loss, for acclimatised and nonacclimatised subjects. These limits are intended to protect 95% of the population. Measuring strategy: a strategy was developed to assess the risks in any working situation with varying conditions of climate, metabolic rate or clothing. A detailed methodology was developed in three stages: an "observation" method for the recognition of the conditions that might lead to thermal stress; an "analysis" method for evaluating the problem and optimising the solutions; and an "expert" method for in-depth analysis of the working situation when needed. the different results were used to prepare a revision of the interpretation procedure proposed in the ISO standard 7933. We validated the modified approaches using the database. This involved the whole range of conditions for which the model was extended, namely conditions with high and low radiation, humidity and air velocity as well as fluctuating conditions. Based on these results, the predicted heat strain model was developed: it is presently proposed as an ISO and CEN standard.
At the request of the European Commission and in the framework of the European Machinery Directiv... more At the request of the European Commission and in the framework of the European Machinery Directive, research was performed in five different laboratories to develop specifications for surface temperature limit values for the short-term accidental touching of the fingertip with cold surfaces. Data were collected in four laboratories with a total of 20 males and 20 females performing a grand total of 1655 exposures. Each touched polished blocks of aluminium, stainless steel, nylon-6 and wood using the distal phalanx of the index finger with a contact force of 1.0, 2.9 and 9.8 N, at surface temperatures from +2 to -40 degrees C for a maximum duration of 120 s. Conditions were selected in order to elicit varying rates of skin cooling upon contact. Contact temperature (TC) of the fingertip was measured over time using a T-type thermocouple. A database obtained from the experiments was collated and analysed to characterize fingertip contact cooling across a range of materials and surface temperatures. The database was subsequently used to develop a predictive model to describe the contact duration required for skin contact temperature to reach the physiological criteria of onset of pain (15 degrees C), onset of numbness (7 degrees C) and onset of frostbite risk (0 degrees C). The data reflect the strong link between the risk of skin damage and the thermal properties of the material touched. For aluminium and steel, skin temperatures of 0 degrees C occurs within 2-6 s at surface temperatures of -15 degrees C. For non-metallic surfaces, onset of numbness occurs within 15-65 s of contact at -35 degrees C and onset of cold pain occurs within 5 s of contact at -20 degrees C. The predictive model subsequently developed was a non-linear exponential expression also reflecting the effects of material thermal properties and initial temperature. This model provides information for the protection of workers against the risk of cold injury by establishing the temperature limits of cold touchable surfaces for a broad range of materials, and it is now proposed as guidance values in a new international standard.
Les “facultés” de travail peuvent être définies comme un équilibre entre les caractéristiques pro... more Les “facultés” de travail peuvent être définies comme un équilibre entre les caractéristiques propres au travailleur-état de santé individuel, ressources personnelles, efficacité, intention de rester, connaissance et capacités-et les exigences liées au travail-charge psychosociale, charge de travail physique, sécurité du travail, exigences de la fonction-auxquelles il doit faire face. En Belgique, la Direction Humanisation du travail du Service Public Fédéral Emploi, Travail et Concertation sociale a entamé une série d’études afin d’approfondir ce concept et créer un questionnaire complet, en français et en néerlandais, appelé le VOW/QFT. Le VOW/QFT a pour but d’étudier comment le travailleur perçoit et vit l’équilibre entre ses propres caractéristiques et les exigences auxquelles il est confronté. L’objectif est de rendre ce questionnaire facile d’accès et d’utilisation pour les professionnels de la santé au travail, leur permettant de disposer d’un outil scientifique et valide pou...
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