Title
Temperature limit values for touching cold surfaces with the fingertip
Author
Geng, Q.
Holme, I.
den Hartog, E.A.
Havenith, G.
Jay, O.
Malchaires, J.
Piette, A.
Rintama, H.
Rissanen, S.
TNO Defensie en Veiligheid
Publication year
2006
Abstract
Objectives: 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. Methods: 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 -40C 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. Results: 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 (15C), onset of numbness (7C) and onset of frostbite risk (0C). Conclusions: 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 0C occurs within 2-6 s at surface temperatures of -15C. For non-metallic surfaces, onset of numbness occurs within 15-65 s of contact at -35C and onset of cold pain occurs within 5 s of contact at -20C. 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. Keywords: Cold surfaces; contact temperature; finger touching; machine safety
Subject
Health
Cold surfaces
Contact temperature
Finger touching
Machine safety
Aluminum
Cold effects
Low temperature phenomena
Research and development management
Stainless steel
Thermodynamic properties
Cold surfaces
Contact temperature
Finger touching
Machine safety
Occupational risks
nylon
stainless steel
adult
cold exposure
cold injury
controlled study
cooling
data analysis
data base
distal phalanx
female
force
hand paresthesia
human
human experiment
index finger
information processing
laboratory
male
materials
model
normal human
occupational exposure
occupational hazard
prediction
priority journal
protection
risk assessment
skin
skin injury
skin pain
skin protection
skin temperature
surface property
temperature measurement
temperature sensitivity
touch
wood
worker
thermal physiology
cold
To reference this document use:
http://resolver.tudelft.nl/uuid:96cadfbe-8f64-45b3-8d0e-d938d47f95c8
DOI
https://doi.org/10.1093/annhyg/mel030
TNO identifier
16355
Source
Annals of Occupational Hygiene Advance, 50 (8), 851-862
Document type
article