Entity

Time filter

Source Type

Seibersdorf, Austria

Schulmeister K.,Seibersdorf Laboratories
The World's Leading Conference on Laser Safety, ILSC 2011 - International Laser Safety Conference | Year: 2011

Laser products that emit continuous wave (cw) visible radiation with powers up to 5 mW have been widely used for pointing and alignment purposes for more than 30 years. Under IEC 60825-1 such lasers are classified as Class 3R. Experience shows that these lasers are quite safe for momentary accidental exposure, even though the exposure limit might be exceeded by up to a factor of 5. In this paper a case is made that this general experience of relative safety should not be extrapolated to pulsed emissions and extended sources without a more detailed quantitative risk analysis. Following the update of the exposure limits by ICN1RP, ANSI and IEC, the minimal safety factor of about 2.5 will apply to a much wider range of parameter combinations as compared to the current limits. For the case that Class 3R AEL values remain linked to the MPEs by a factor 5 in all cases, there will be many more products where an exposure can exceed the injury threshold even for momentary accidental exposure. Source


Schmid G.,Seibersdorf Laboratories | Kuster N.,Foundation for Research on Information Technologies in Society ITIS | Kuster N.,ETH Zurich
Bioelectromagnetics | Year: 2015

The objective of this paper is to compare realistic maximum electromagnetic exposure of human tissues generated by mobile phones with electromagnetic exposures applied during in vitro experiments to assess potentially adverse effects of electromagnetic exposure in the radiofrequency range. We reviewed 80 in vitro studies published between 2002 and present that concern possible adverse effects of exposure to mobile phones operating in the 900 and 1800MHz bands. We found that the highest exposure level averaged over the cell medium that includes evaluated cells (monolayer or suspension) used in 51 of the 80 studies corresponds to 2W/kg or less, a level below the limit defined for the general public. That does not take into account any exposure non-uniformity. For comparison, we estimated, by numerical means using dipoles and a commercial mobile phone model, the maximum conservative exposure of superficial tissues from sources operated in the 900 and 1800MHz bands. The analysis demonstrated that exposure of skin, blood, and muscle tissues may well exceed 40W/kg at the cell level. Consequently, in vitro studies reporting minimal or no effects in response to maximum exposure of 2W/kg or less averaged over the cell media, which includes the cells, may be of only limited value for analyzing risk from realistic mobile phone exposure. We, therefore, recommend future in vitro experiments use specific absorption rate levels that reflect maximum exposures and that additional temperature control groups be included to account for sample heating. Bioelectromagnetics. 36:133-148, 2015. © 2015 Wiley Periodicals, Inc. Source


Schulmeister K.,Seibersdorf Laboratories
The World's Leading Conference on Laser Safety, ILSC 2013 - International Laser Safety Conference | Year: 2013

Depending on the type of product and usage, three different categories of legal requirements are identified that apply for laser products in Europe, in particular for the case that the exposure limit for the eye is or can be exceeded (Class 3R, 3B, 4): product safety legislation, i.e. what is allowed to be placed on the market; work place safety regulations if the product is used at the workplace; and what could be referred as event safety legislation, when the laser radiation can expose general population, for instance the audience in a cinema. All of these legal requirements are to a degree relevant for the manufacturer of laser products even though the latter two not directly. However, if the user of a device has to deal with significant safety measures and restrictions by the authorities, then this is a problematic situation also for the manufacturer of the product in terms of attractiveness of the product. The legal situation will be summarized and commented on for the case of Class 3R laser products and laser shows. Source


Schulmeister K.,Seibersdorf Laboratories
The World's Leading Conference on Laser Safety, ILSC 2013 - International Laser Safety Conference | Year: 2013

While there are deterministic rules laid down in IEC 60825-1 regarding how to determine the accessible emission for the nominal output and classify a laser product, there are also aspects where a probabilistic risk analysis is important. With the revision of IEC 60825-1 (third edition), the role of risk analysis will be emphasized and somewhat widened. Examples where risk analysis plays a role are: is a single fault relevant for classification (i.e. reasonably foreseeable); is additional functional safety (automated power reduction for case of fault) needed; is it permitted that automated power reduction is not fast enough to assure AEL is not exceeded; design of scanning safeguards; and reliability of interlocks. Also, independent of the above issues of functional safety, it should be noted that governmental market surveillance agencies in Europe use risk analysis to decide if a product (such as a Class 3R laser) is acceptable to be marketed as consumer product or not. In this paper, the principles of risk analysis will be discussed as well as examples given where risk analysis has an important role for the manufacturer of a laser product. This paper offers a first input to develop guidance how risk analysis and IEC 61508 in particular can be applied in the design of a laser product. Source


Schulmeister K.,Seibersdorf Laboratories
The World's Leading Conference on Laser Safety, ILSC 2013 - International Laser Safety Conference | Year: 2013

The upcoming new edition of IEC 60825-1 allows to treat the light output which replaces traditional light sources by laser powered emissions, and that do not exceed a certain radiance, to be assessed under IEC 62471 (the lamp safety standard series). Since lamps (at distances where they can be hazardous) are all extended sources, the exposure and emission limits for the retina are specified in terms of radiance. Radiance has very attractive properties for extended sources, but is not intended to be applied to characterize point sources. During the discussion in the standard committee TC76, the level of radiance of a 1 mW laser pointer (which is known to be safe) was discussed. However, the calculation of radiance for safety purposes needs to consider a proper choice of source size and averaging due to the small beam diameter. The concept of radiance is discussed as applied to the sun, a 1 mW laser pointer and a laser illuminated phosphor, as well as the current and new exposure limit for broadband radiation. Source

Discover hidden collaborations