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#150964 - 03/05/06 02:52 PM Safety with Lasers?
Trumpy Offline

Member

Registered: 07/05/02
Posts: 8540
Loc: SI,New Zealand
Guys,
I heard a story locally yesterday about a couple of kids that were mucking around with a laser pointer device and one shone the thing into the others eyes, effectively damaging his eyesight.
I don't know a great deal about these devices, but I do know you should never have a laser beam go into your eye.
What is the risk with these devices?.
With the prolifertaion of laser sights and other such measuring devices on construction sites these days, how do you keep yourself safe from the emitted beam(s)?.
I've been told that there is a certain type of eyewear that you can use to protect your eyes from a laser beam.
Can anyone help?.
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Let's face it, these days if you're not young, you're old - Red Green grin

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#150965 - 03/05/06 03:35 PM Re: Safety with Lasers?
renosteinke Offline
Cat Servant
Member

Registered: 01/22/05
Posts: 5305
Loc: Blue Collar Country
The vast majority of lasers out there...your pointers, gun sights, levels, etc....use a laser whose power is not sufficient to cause permanant damage to the eyes.

In an industrial setting, where the laser is used for woodburning, metal cutting, etc.....that's a different story entirely.

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#150966 - 03/05/06 03:52 PM Re: Safety with Lasers?
Dnkldorf Offline
Member

Registered: 12/12/04
Posts: 1091
Loc: nowhere usa
No expert here, but I would guess the laser pointer is a concentrated beam of light.

Taking a concentrated beam of light and pointing it directly at the cornea, which in turn focuses that beam even more in the eye itself doesn't sound too safe to me..........

As for safety glasses, I just have to assume, that the glasses must block the infared light from concentrating on the eye..


Dnk....

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#150967 - 03/06/06 12:52 AM Re: Safety with Lasers?
Trumpy Offline

Member

Registered: 07/05/02
Posts: 8540
Loc: SI,New Zealand
John,
Would you disparage the lower powered lasers used for eye surgery?.
Also, why is it that all lasers come with a warning symbol on them?, regardless of thier power?.
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Let's face it, these days if you're not young, you're old - Red Green grin

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#150968 - 03/06/06 04:51 AM Re: Safety with Lasers?
Zog Offline
Member

Registered: 09/13/05
Posts: 116
Loc: Charlotte, NC
The NFPA 70E has a section in the back for working with lasers, try there.
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#150969 - 03/06/06 12:32 PM Re: Safety with Lasers?
feather Offline
Member

Registered: 02/28/06
Posts: 25
Loc: Santa Maria CA USA
American Optical #588 is what we use for laser micrometers remember you must match wave length for proper protection

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#150970 - 03/06/06 04:46 PM Re: Safety with Lasers?
renosteinke Offline
Cat Servant
Member

Registered: 01/22/05
Posts: 5305
Loc: Blue Collar Country
Trumpy, I would not disparage the "low powered" lasers udes for eye surgery....it's just that they are not "low powered" according to our regs. The laser pointers, etc, that one commonly encounters are the true "low power" as out FCC defines it.

Trying to obtain anything with more power is quite a bit more difficult, and has far more demanding power supplt requirements.

The comment about wavelength is quite correct. The most dangerous lasers -the CO2- are absolutely invisible....yet will be completely blocked by clear plexiglass (acrylic).

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#150971 - 03/12/06 03:39 AM Re: Safety with Lasers?
Trumpy Offline

Member

Registered: 07/05/02
Posts: 8540
Loc: SI,New Zealand
John,
It is still a "concentrated" beam is it not?.
And still conducive to eye damage?.
_________________________
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#150972 - 03/12/06 02:59 PM Re: Safety with Lasers?
iwire Offline
Moderator

Registered: 01/05/03
Posts: 4343
Loc: North Attleboro, MA USA
OSHA (Occupational Safety & Health Administration) covers constrution workers and most other employees in the US.

Here is a few of their standards in regards to lasers. It is intresting to note that all lasers are treated eqully by OSHA.

 Quote:
1926.54(a)

Only qualified and trained employees shall be assigned to install, adjust, and operate laser equipment.

1926.54(b)

Proof of qualification of the laser equipment operator shall be available and in possession of the operator at all times.

1926.54(c)

Employees, when working in areas in which a potential exposure to direct or reflected laser light greater than 0.005 watts (5 milliwatts) exists, shall be provided with antilaser eye protection devices as specified in Subpart E of this part.

1926.54(d)

Areas in which lasers are used shall be posted with standard laser warning placards.

1926.54(e)

Beam shutters or caps shall be utilized, or the laser turned off, when laser transmission is not actually required. When the laser is left unattended for a substantial period of time, such as during lunch hour, overnight, or at change of shifts, the laser shall be turned off.

1926.54(f)

Only mechanical or electronic means shall be used as a detector for guiding the internal alignment of the laser.

..1926.54(g)

1926.54(g)

The laser beam shall not be directed at employees.

1926.54(h)

When it is raining or snowing, or when there is dust or fog in the air, the operation of laser systems shall be prohibited where practicable; in any event, employees shall be kept out of range of the area of source and target during such weather conditions.

1926.54(i)

Laser equipment shall bear a label to indicate maximum output.

1926.54(j)

Employees shall not be exposed to light intensities above:

1926.54(j)(1)

Direct staring: 1 micro-watt per square centimeter;

1926.54(j)(2)

Incidental observing: 1 milliwatt per square centimeter;

1926.54(j)(3)

Diffused reflected light: 2 1/2 watts per square centimeter.

1926.54(k)

Laser unit in operation should be set up above the heads of the employees, when possible.

1926.54(l)

Employees shall not be exposed to microwave power densities in excess of 10 milliwatts per square centimeter.



Here is the most recent OSHA Standard Interpretation referencing 1926.54.

 Quote:
Standard Interpretations
07/12/1993 - Class I lasers.

Standard Interpretations - Table of Contents

• Standard Number: 1926.54

July 12, 1993

Mr. Roy O'Connor
National Sales Manager
Topcon America Corporation
65 West Century Road
Paramus, NJ 07652


Dear Mr. O'Connor:

This is in response to your May 27 letter requesting a letter of interpretation of the Occupational Safety and Health Administration (OSHA) regulations addressing class I lasers. I apologize for the delay in responding to your request.

Although the degree of hazard associated with low power lasers used in the construction industry is relatively low and Class I lasers are typically not hazardous, the OSHA construction industry standard for lasers at 29 CFR 1926.54 does not differentiate with respect to class of lasers and, thus, all lasers are covered by the standard. However, except for violations based on 1926.54(j), violations of 1926.54, in the case of the Class I lasers, are regarded by OSHA as "de minimis" which means there will be no citations, no penalty, and no abatement date issued for these violations found during an inspection. However, the specific exposure limits of paragraph (j) of the OSHA standard do not depend on the laser's class and will continue to have full effect. Consequently, if a violation of paragraph (j) is found, then the de minimis policy no longer applies and all other provisions of 1926.54 may be cited and penalties and abatement dates may be issued.

If you have any further questions, contact me or Mr. Dale R. Cavanaugh of my staff at (202) 219-8136.

Sincerely,

Roy F. Gurnham, P.E., Esq. Director
Office of Construction and Maritime
Compliance Assistance




Bob
_________________________
Bob Badger
Construction & Maintenance Electrician
Massachusetts

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