1. Lead Test Kits

On-site surface sampling test kits are commercially available. OSHA neither endorses these kits nor recommends their use. The effectiveness and applicability of these kits are the responsibility of the user.

The Lead Test Kits evaluated, their contents, and accessories are listed in Table 1. All kits and accessories were purchased on the open market. The color responses are similar for both kits.

2. Interferences

According to the manufacturers, several interferences are possible. These interferences appear to be common to both brands of lead detector kits studied. They are discussed in Table 2.

Table 2
Lead Detection Interferences

3. Evaluation Criteria

A variety of samples of paint and other materials were collected or prepared. These were then tested using the manufacturer's instructions given for the kit being examined. The appearance of a pink color, indicating the presence of lead at a significant level, was noted for the samples. Lack of response was also noted. Lead content in the samples was confirmed by sample analysis using established OSHA SLTC analytical methods ID-125G (ICP) and ID-121 (AAS) to determine if the results from the kit tests met the HUD conditions (a positive response if the lead content was >0.5% by weight, a negative response if it was <0.5%). Some of the glass and metal samples were also qualitatively or semiquantitatively screened by XRF using OSHA Method ID-204.

4. Test Sources for Lead

Paint samples were tested along with a few other materials of interest. The sources of these samples are listed as follows:

1. Paints which were painted or sprayed onto wood or galvanized steel.
2. Paint from painted wood or plaster from homes.
3. Lead metal, lead-containing glass, lead chemicals.
4. Non-lead solder and metals used in solder other than lead (antimony, tin).
5. Surfaces in plastic Petri dishes which had films consisting of a readily soluble lead compound with surface concentrations of 0.1 to 2.4 mg/cm².

5. Lead Test Equipment

Manuals for each kit must be consulted before use. The tests done on the various materials were performed according to the manufacturer's instructions supplied in each kit.

LEAD CHECK™ Test Kit (HybriVet Systems, Inc.) (10.13.):

The contents of each kit are listed in Table 1. Each Lead Check swab contains two ampoules of chemicals; however, the composition of these chemicals is not given.

For all testing applications, the following steps are used to activate each swab:

1. CRUSH - With the swab tip pointing up, squeeze and crush points marked "A" and "B" located on the barrel of the swab.
2. SHAKE AND SQUEEZE - With the swab tip pointing down, shake twice and squeeze gently until the yellow liquid appears on the swab tip - the swab is now activated for testing.
3. RUB - While squeezing gently, rub the swab tip on the test area for 30 sec.

If the swab turns pink, the test is positive and lead is present. If the swab indicates no color change, the test is negative and no leachable lead has been detected. All negative results must be confirmed using the Test Confirmation Card. If the swab does not turn pink after testing, rub the swab tip on one of the unused test dots on the card. If a pink or red color appears on either the dot or swab, a negative result is substantiated. If the test dot and/or swab does not turn pink or red, the test was invalid and must be repeated with a new swab. All testing, including any necessary confirmation card testing, must be completed within two min.

CAUTION: The test dots on the Test Confirmation Card contain minute amounts of lead. Do not touch these areas. Wash hands after each use.

Procedure for examining painted wood or metal surfaces:

1. Clean and remove all dust and dirt from the area to be tested.
2. With a clean knife or scraper, cut a small ¬ in notch at a diagonal to expose all painted layers down to the bare surface - lead may be present in any layer of paint.
3. Activate a swab.
4. Rub the activated swab in the exposed cross-section for 30 sec. If any layers contain lead, a positive result will occur - The swab or surface will turn pink.

Note: With certain paints, lead is difficult to extract, and it may take longer for positive results to develop. Examine the test surface 30-60 min after the test has been performed before assuming a test result.

Note: "Bleeding" may occur when testing surfaces that are painted red. Moisten cotton-tipped applicators with a few drops of distilled white vinegar. Rub the moistened cotton on the red surface. If a red color appears on the cotton, Lead Check Swabs cannot be used. Send a sample of the material to a certified laboratory or use another type of field procedure for further testing.

Procedure for examining lead-containing ceramics or glass:

1. Activate the swab.
2. When testing ceramics, rub the swab over all patterns with different colored glazes and any cracks or chipped areas. If lead is leaching from the surface, the swab will turn pink.
3. When testing glass, rub the swab over the surface.
4. When testing lead crystal, rub the swab on the inside surface of the glass or other vessel.

Procedure for examining solder (plumbing, food cans):

1. Wipe off the solder joint with a paper towel or cloth.
2. Using an emery board or sandpaper, lightly score the surface to be tested.
3. Activate the swab.
4. Squeeze one drop of yellow liquid from the swab onto the solder surface.
5. Touch the swab to the wet solder surface and rub gently for only 10 sec or less.
6. The swab will turn pink if the solder contains greater than 2% lead.

Procedures for examining lead in dust:

1. Activate the swab.
2. Rub activated the swab in the dust for 30 sec. If the dust contains lead, the swab will turn pink.

Note: Avoid rubbing the swab into large amounts of "dirt dust" as this will obscure the color test results on the swab.

LEAD ALERT™ All in One™ Professional Kit (Sensidyne) (10.14.):

Two types of kits are available. The contents of each type of kit are listed in Table 1. The Indicating Solution contains rhodizonate ion which reacts with lead to give a pink color (10.12.); the composition of the Leaching Solution is not given. For recovering paint down to the base material from painted objects, a kit containing a Coring Tool and cleaning brush is available for use with the Lead Alert Kits (see Table 1). The initial preparation and testing of the Indicating Solution takes about 10 min. Most tests take about one to three min to perform.

Procedure for activating the indicating solution:

1. Remove the red cap from the "Indicating Solution" bottle.
2. Carefully remove the dropper insert by rolling/twisting it off the bottle.
3. Open the foil package and place the Indicating Tablet into the bottle of solution.
4. Replace the dropper insert and the red cap. Tighten the cap and shake the bottle for one min.
5. Allow the bottle to stand for 5 min, then shake it again until the solution turns yellow. The tablet will not completely dissolve; however, this is normal. The Indicating Solution is now ready for use. (For reference purposes, write the date on the bottle when the reagent is activated.)
6. When testing has been interrupted for more than 15 min, shake the indicating solution vigorously again for 5-10 sec before resuming testing. When the testing has been interrupted for several hours or days, shake the indicating solution for 30 sec and perform a Positive Control Test before resuming testing.

Procedure for carrying out the Positive Control Test to verify the effectiveness of the testing system:

1. Place one drop of the Leaching Solution on the Positive Control Strip in the center of one of the numbered circles.
2. Let it sit for 10 sec, then add one drop of the activated Indicating Solution.
3. A pinkish (rose) stain will appear in the circle and indicates the test kit is working properly. If the rose stain does not appear, the activity of the Indicating Solution has expired.

CAUTION: For testing purposes, the areas inside the circles on the Positive Control Strip contain minute amounts of lead. Do not touch these areas. Wash hands after each use. After testing and when dry, put the Positive Control Strip back into its pouch.

Procedure for carrying out a total lead test on paint:

1. Remove a fresh adhesive-backed collection paper and fold it in half. Apply the paper close to the area to be tested.
2. Using the coring tool, cut down into the surface. Scrape the paint from inside the circle and place it on the paper. Be sure to remove all layers. Thoroughly clean the coring tool.
3. Transfer the paint from the paper to a plastic vial. Grind up the paint with a plastic rod for about 10 sec.
4. Add three drops of Leaching Solution to the vial and grind the contents for another 10 sec. Let the vial sit for 20 sec.
5. Add three drops of Indicating Solution to the tip of a fresh sample collector. Touch the surface of the liquid in the plastic vial with the tip of the collector.
6. A pink color on the collector tip indicates lead in amounts greater than the limit of 0.5% by weight of lead.

Note: When testing red painted surfaces it is possible that the red paint may "bleed out" into the test surface on the sample collector. "Bleed Out" Test: Look at the liquid above the solid in the vial in Step d. above. If the fluid is red, the sample should be sent to a certified analytical laboratory for further testing or another type of field procedure should be used.

Procedure for carrying out a surface lead test on paint (top layer only):

1. Apply two drops of Leaching Solution to the tip of a sample collector.
2. Rub the sample collector tip on the surface to be tested for 10-15 sec.
3. Add two drops of Indicating Solution to the sample collector tip.
4. A pink color on the collector tip indicates lead in amounts greater than the limit of 0.5% by weight of lead for the top layer of paint.

Procedure for carrying out the sanding test (when only the top one or two layers of paint are to be sanded or otherwise disturbed in preparation for painting. If more than two layers are to be sanded or otherwise disturbed, use the total lead test described above):

1. Use a fresh abrasive strip to rub lightly over the painted surface. An area of about 0.5 in² is sufficient. Avoid contact with or breathing of dust.
2. Apply two drops of Leaching Solution to a sample collector tip and rub it over the sanded area.
3. Add one more drop of Leaching Solution to the paint dust now on the collector.
4. Leave for 30 sec. Add two drops of Indicating Solution to the same area on the collector tip.
5. A pink color on the collector tip indicates lead in amounts probably greater than the limit of 0.5% by weight of lead for the layer(s) of paint affected.

Note: "Bleeding" may occur when testing surfaces that are painted red. During the sanding test on red paint, examine the surface of the sample collector after the Leaching Solution and paint dust have been added to the tip. If the color does not spread, the red pigment will not interfere with the test. If it does spread, send a sample of the material to be tested to a certified analytical laboratory or use another type of field procedure.

Procedure for determining lead in paint, metal, and dust particles:

1. Apply two drops of Leaching Solution to a sample collector tip.
2. Apply a very small amount of fine particles of the target material (ground paint chips, paint dust, house dust, etc.) to the tip of the collector.
3. Apply one or two more drops of Leaching Solution to the particles on the tip. Wait 30 sec.
4. Apply two drops of Indicating Solution to the collector tip; watch for a color change.
5. A pink color on the collector tip indicates lead in amounts probably greater than the limit of 0.5% by weight of lead.

Procedure for plumbing pipes, joints, and fixtures:

1. Locate an area where water pipes are exposed. Determine if any soldered joints are present.
2. Sand the pipe and/or solder joint lightly with a fresh abrasive strip.
3. Apply two drops of Leaching Solution to the tip of a sample collector.
4. Rub the tip of the collector on the surface to be tested for 10-15 sec.
5. Add two drops of Indicating Solution to the collector tip; watch for a color change.
6. A pink color on the collector tip indicates lead in amounts probably greater than the limit of 0.5% by weight of lead.

6. Results

Results are compiled from samples taken using six lead check kits and two lead alert kits. Results are dependent on manufacturer quality control practices and may vary from lot to lot.

• Lead Paints
• Lead Metals, Chemicals, and Glass
• Lead-Free Metals
• Surfaces in Petri Dishes Containing Lead Ranging from 0.1 to 2.4 mg/cm²

Lead Paints

The results of the tests conducted with the lead detector kits on paints freshly applied to wood and galvanized steel surfaces are summarized in Table 3. The paints were allowed to dry for a period of several days prior to testing.

Table 3
Paints Brushed or Sprayed onto Wood or Galvanized Steel (Metal)

Footnotes

¹ Lead Check Swabs which indicated a negative result were checked with the positive test strip; all reacted positive to the strip.

² For the Lead Check tests, the swab was rubbed over the paint. No cutting into the paint was done.

³ The Lead Alert tests were done using the Sanding Test except where indicated.

⁴ For the ICP analyses, the paints were applied to tared filters and allowed to dry. The filters were then reweighed. Dry weights were used in all calculations. All weights were taken to the nearest 0.1 mg.

⁵ All lead results are reported. Any other elements >1% are also reported. Barium, if analyzed, is reported. Barium was analyzed if orange coloration was observed with the kit reagents.

⁶ The prepared Sunfire 421 Acrylic paint, although capable of being sprayed, was applied to the wood and metal surfaces with a paint brush. The other paints were spray paints and were applied to the wood and metal surfaces by spraying.

⁷ The ICP analysis of the Sunfire 421 Acrylic paint was done on the pigment solution component only. The complete paint mixture requires the addition of two additional components: hardener and a diluent solvent.

⁸ See Table 2 (Interferences). Lead chromate appears to be present. Lead chromate is extremely difficult to detect by these techniques. The chromate appears to interfere with the lead analysis. Also, the orange chromate color could obscure any faint pink color which might be present.

⁹ For Lead Check tests on the Sunfire 421 Acrylic paint on both wood and metal, the paint sample was sanded with sandpaper from Lead Alert Kit, otherwise no pink color was observed. The pink color was slow in developing.

¹⁰ Lead Alert tests on the Sunfire 421 Acrylic paint on wood were done with both the Sanding Test and the Coring Test; after 30 min, no pink color had developed in either test. The test of the paint on metal was done with the Sanding Test; a faint pink color was slow in developing.

¹¹ Upon testing the DAP Broma #112 Pink paint, a shade of pink was observed which appeared characteristic of the color of the paint itself. The color was different from the pink normally observed when lead was present. The results of the tests carried out on paint coatings on wood and plaster samples from two homes in the Salt Lake City, UT area are summarized in Table 4.

Table 4
Paints Obtained from Painted Wood or Plaster from Older Homes

Footnotes

¹ Lead Check Swabs which indicated a negative result were checked with the positive test strip; all reacted positive to the strip.

² All lead results are reported. Any other elements >1% are also reported. Barium, if analyzed, is reported. Barium was analyzed if orange coloration was observed with the kit reagents.

³ Home #1 was ~50 years old; Home #2 was ~40 years old.

⁴ Paint had fine cracks in it. The testing solution may have penetrated to deeper layers.

⁵ Conclusion: Lead was present in the deepest layers of paint but not in the surface layer. Lead-free paint had been applied over paint containing lead. In one of the Lead Check tests on the baseboard, possibly more of the lead-containing layer was exposed than in the other two tests.

⁶ Sample was collected by laying a paint chip on a Collection Paper and cutting a disk for analysis with the Coring Tool.

⁷ The extra time in these Lead Alert tests was taken to observe if the initial apparent negative results were actually indicative of a low lead content or if the color was slow in developing. In all these cases, no color development was observed with increasing time, and therefore these appeared to be true negative results. It thus appears that in most Lead Alert tests when interferences are not present, a positive or negative result will be apparent within a few min.

⁸ If gypsum was present in the plaster, this could have interfered with the surface lead tests on the paint formerly next to the plaster. For the Lead Check test carried out on this paint, the slight pink color was slow in developing.

Lead Metal, Chemicals, and Glass

The results of the tests carried out with the lead detector kits on lead metal (both powder and sheet) and lead-containing chemicals and glass are summarized in Table 5.

Table 5
Lead Metal, Lead Chemicals, Lead-Containing Glass

Footnotes

¹ Lead Check Swabs which indicated a negative result were checked with the positive test strip; all reacted positive to the strip.

² Samples were initially digested with hydrofluoric acid to remove silica. Lead results are reported.

³ Paint, metal, and dust particles procedure was used.

⁴ Dust test procedure was used. The activated swab was rubbed into the powdered chemical.

⁵ See Table 2 (Interferences). Lead chromate is extremely difficult to detect by these techniques. The chromate appears to interfere with the lead analysis. Also, the orange chromate color could obscure any faint pink color which might be present.

⁶ Ceramics and lead crystal procedure was used. The product literature indicates that 1-2 ug of leachable lead can be detected.

⁷ Surface test procedure was used.

Lead-Free Metals

The results of the tests carried out with the lead detector kits on lead-free metals (non-lead solder and metals used in these types of solders such as antimony and tin) are summarized in Table 6. The purpose of these tests was to determine if any of these metals would give a positive pink reaction with the test procedures.

Table 6
Non-Lead Solder and Metals Used in Solder Other than Lead (Antimony, Tin)

Footnotes

¹ Solder (Plumbing and Food Cans) test procedure was used. Sandpaper from Lead Alert Kit was used for sanding.

²If too much metal dust was picked up on the swab, a purplish color was obtained which could easily have obscured a small amount of pink color. The observations reported here were made under conditions where the metal dust collected on the swab was small enough not to obscure any pink color which might have been present.

³Lead Check Swabs which indicated a negative result were checked with the positive test strip; all reacted positive to the strip.

⁴Plumbing Pipes, Joints, and Fixtures test procedure was used.

⁵The following X-ray fluorescence analysis data were obtained for the solder:

Surfaces in Petri Dishes Containing Lead Ranging From 0.1 to 2.4 mg/cm²

As mentioned previously, the HUD Interim Guidelines action level for lead based paint is a lead content of 1.0 mg/cm² as measured by an XRF analyzer or, when using chemical testing, it is either 0.5% by weight or 1.0 mg/cm² (10.9.). In the study reported by Pace Environs on 243 paint samples, the Lead Alert Test Kit very satisfactorily met the conditions necessary to meet HUD performance standards for lead tests, as far as the 0.5% lead content (determined by AAS) was concerned. In a comparison study using a laboratory XRF instrument, the XRF surface measurements for mg/cm² compared well with the AAS determinations except for three samples near the 1 mg/cm² amount (>1 mg/cm² lead by lab XRF but >0.5% lead by AAS) (10.12.).

In a test to determine the response of the kits to various levels of surface lead, a series of plastic Petri dishes containing soluble lead films were prepared by adding various amounts of a solution of lead nitrate in water to each of several dishes. Surface coatings of 0.1, 0.6, 1.0, 1.4, and 2.4 mg/cm² of lead were prepared. The solution was then evaporated. Since the solution tended to form liquid beads during evaporation, isopropanol was added to assist in spreading the solution over the surface of the Petri dish bottom to obtain as nearly a uniform spread as possible while evaporation was proceeding. The deposits, however, did not appear very uniform.

Both kits showed positive pink results when the swabs were applied to the 0.1 mg/cm² surface. No pink response should have been observed until amounts near or above 1.0 mg/cm² were tested, in order to meet the HUD conditions discussed above. Evidently the loosely held lead in this experiment does not correspond to the much more tightly bound lead in paint that the kits are designed for, and thus it reacts more readily with the kit indicating solutions. Therefore, this experiment using loosely held layers of lead does not constitute a rigorous experiment.

7. Observations and Evaluation of Performance of the Lead Detector Kits

During the course of the work with the Lead Alert Kit, it was found that the Indicating Solution occasionally needed longer vigorous shaking times than specified in the instructions to be fully activated. This was the case both upon initial activation after first adding the pill to the solution, and activating the solution after it had been standing for some time. If the pink stain formed in the Positive Control Test is very faint, the solution should be shaken vigorously for an additional minute and then be tested again.

Chromate interference can be a serious problem in lead analysis. In the case of the Sunfire 421 Enamel, which contained a large amount of lead and also a significant amount of chromium presumably present as chromate, no positive result for lead was obtained on a surface test unless the paint was sanded, and then the pink color was very slow to develop. The pink color in the Lead Alert test on metal was very faint. No pink color was observed with the Lead Alert total lead (coring) test. The Lead Check tests gave comparable positive responses on wood and metal substrates; however, the paint needed to be sanded before testing, and the pink color was very slow in developing. The faint pink color tended to be obscured by the orange color present. No pink color was observed with the test on lead chromate powder.

In two of the tests performed (on the Sprayon Industrial Primer Surfacer 00341 and the old piece of white-painted wood in the Home #2 back yard), a light orange color was obtained. Barium is sometimes present in paint, and so these paints were analyzed for barium. However no barium was found. The reason for the orange color obtained in the lead tests was unknown.

In Table 3, the paints indicated were dispensed from spray cans except for the Sunfire 421 Enamel, which was mixed according to instructions and applied with a paint brush. All of the spray paints showed lead contents <0.5% upon ICP analysis, and all gave negative results with both test kits for wood and metal surfaces. In Table 4, tests on surfaces containing an overall lead content of well above 0.5% indicated that both the initial and final layers of each paint sample contained significant lead, although the tests on each final layer are questionable since there were fine cracks in these layers. Surface tests on paint samples containing some lead but at an overall content of <0.5% gave positive tests on the initial layer but negative results on the outside layer; evidently the substrate had been initially painted with lead-containing paint but had later been painted over with paint containing little or no lead, thus reducing the overall lead content of the entire painted surface. This "diluting" of the lead-based painted surface with no-lead paints is typical for many painted surfaces in existence. The results obtained with the Lead Alert Kit using the Total Lead (Coring) test gave positive results for paint containing an overall content of >0.5% lead and negative results for paint containing an overall content of <0.5% lead, thus meeting the HUD requirements. The results and observations tend to indicate that in the Lead Alert tests when interferences such as chromate are not present, a definite positive or negative result will be apparent within a few min, as no change in color was observed with time. The Lead Check test involving cutting into the paint to expose all layers appears designed to give a positive test if any layer contains significant lead; however, the paint must be cut into at a sharp angle with respect to the surface so that all layers are adequately exposed. As mentioned previously, the product literature indicates that 1-2 ug of leachable lead can be detected (10.7.). Interference from plaster on the tests appeared to be evident in paint chips recovered from a plastered surface. The outer layer gave negative tests with both kits for lead, and these results should be correct; however, the tests on the inner layer (originally next to the plaster) indicated a negative Lead Alert test result and a questionable positive Lead Check test result (a slight pink border slowly developed). Since the paint had an overall lead content of 0.24%, the conclusion was reached that the inner layer may have had a significant amount of lead but it could not be detected because of interference from gypsum in the plaster. Lead metal and lead chemicals all gave positive results with the kits except for lead chromate with both kits and lead sulfide with the Lead Check Kit (Table 5). The problems with lead chromate have been discussed previously; the reason for the lack of response of lead sulfide to the Lead Check Kit is unknown, except that it may be due to the low solubility of lead sulfide. Lead-free metals, including antimony, tin, and a lead-free solder, were tested with the kits to ensure these metals would not give false-positive test results for lead (Table 6). Both kits gave negative results for these tests, and thus they can reliably distinguish lead from antimony and tin which are often used in lead-free solders. Several lead-containing glasses were tested with these kits (Table 5). Both kits gave negative results. Evidently the lead is so tightly bound as the silicate that it is extremely insoluble, and thus these glasses apparently do not constitute a significant lead hazard.

8. Recommendation

Both kits perform satisfactorily and are capable of identifying lead at the levels given in the Lead Exposure Reduction Act (October 29, 1992) (10.8.) and the Department of Housing and Urban Development (HUD) Interim Guidelines (September, 1990, revised May 1991) (10.9.). For testing paint in which both lead-free and lead-containing paint are present, the Lead Alert Total Lead (Coring) test appears to give appropriate positive and negative results within the HUD requirements (whether greater or less than 0.5% lead by weight). With the Lead Check tests, cutting into the paint to expose all layers will make it possible to determine if any layer has an amount of lead greater than that allowed in the HUD requirements.

1. A positive indication should normally indicate lead is present, and the OSHA CSHO should consider air sampling or exposure control if necessary.
2. A negative indication does not necessarily indicate the absence of lead. If doubt exists regarding the negative value, available bulk material should be submitted for laboratory analysis using spectroscopic techniques or another field procedure should be used.
3. Although lead may be present, an assessment will still need to be made by the OSHA CSHO to determine whether an occupational hazard can or will exist.
4. For the Lead Check test involving cutting into the paint to expose all layers, the paint must be cut into at a sharp angle with respect to the surface so that all layers are adequately exposed.
5. In work with the Lead Alert Kit, the Indicating Solution occasionally may need longer vigorous shaking times than specified in the instructions to be fully activated, both upon initial activation after first adding the pill to the solution, and activating the solution after it has been standing for some time. If the pink stain formed in the Positive Control Test is very faint, the solution should be shaken vigorously for an additional minute and then be tested again.
6. Most tests will be complete in ~2 min; however, when interferences are present, it may require 15-20 min for a pink color to become apparent.
7. Chromate is a serious interferant in both kit tests. Also, lead as lead sulfide could not be detected by the Lead Check Kit.

9. Additional Observations

These kits have been designed not only to detect lead in intact paint, but they also have been designed to detect lead in house dust. There is evidence that most lead exposure in homes is related to dirt brought in from the outside (10.15.), and lead-containing dust is the main route for lead poisoning in children (10.13.). However, lead poisoning has also occurred in children from eating loose paint chips. Intact lead paint should be left alone or be painted over, but if it is to be removed, precautions must be taken. Indiscriminate removal of lead will present a situation similar to that noted with asbestos (10.15.). There are no Federal standards governing the level of lead in house dust at present. The States of Maryland and Massachusetts have established the following standards for lead in dust on specific interior surfaces (10.9.):

Lead-contaminated dust on surfaces may also be collected on commercial wipes for examination using laboratory analysis (10.9.). Sensidyne has a Wipe Sample Test Kit (Catalog No. 225-2401) available for carrying out these tests (10.7.). A cyclone device to be used in conjunction with vacuuming of settled dust has recently been described to address exposure problems associated with lead-containing dusts; this device appears to have high dust recoveries and more consistent recoveries across particle sizes and dust loadings and higher precision across replicate samplings than previous devices (10.16.). A sodium sulfide test for lead is available for tests on skin and other surfaces (10.4.); however, in work for HUD by Dewberry and Davis in 1989, their report concluded that this methodology is unsatisfactory for screening lead present in painted surfaces using HUD action level guidelines (10.12.).

Problems with portable XRF instruments have occurred. One problem is the uncertainty existing in the analysis of paint samples where the lead content is very close to the HUD action level of 1.0 mg/cm² (as discussed earlier) (10.9.). A new field method employing a portable XRF instrument with a high resolution (cooled) semiconductor detector for the analysis of lead in paint and soil has been developed and reported (10.17.). Portable XRF instruments are valuable in lead detection and analysis in the field, but they are also expensive. Also, safety and training considerations need to be made.

The lead detector kits described in this report remain as inexpensive, reliable, and easy to use devices for lead identification provided potential interference precautions are taken.

10. References

10.1. Anderson, L.A., Jr.: Developing an Effective Lead Detection and Abatement Industry: The Role of the Industrial Hygienist. Am. Ind. Hyg. Assoc. J.54: 331-334 (1993).

10.2. Ashley, K. and M.E. McKnight: Lead Abatement in Buildings and Related Structures. ASTM Standardization News: 32-39 (December 1993).

10.3.Lawrence, K.L.: Worker Protection from Lead Exposure. Job Safety and Health Quarterly: 24 (Summer 1993).

10.4. Smith, R.B.: Building a New Lead Standard. Occupational Health and Safety: 32-38 (February 1993).

10.5. The News on Lead. UC Berkeley Wellness Letter: 4-6 (November 1993).

10.6. Rekus, J.F.: A blueprint for Lead Hazards. Occupational Health and Safety: 24-37 (January 1994).

10.7. SKC: Lead Abatement and Monitoring. Eighty Four, PA: SKC, August 1, 1993.

10.8. "Residential Lead-Based Paint Hazard Reduction Act of the Housing and Community Development Act of 1992," Public Law 102-550 Title X, 1992. pp. 106 STAT. 3897-3927.

10.9. U.S. Department of Housing and Urban Development: Lead Based Paint: Interim Guidelines for Hazard Identification and Abatement in Public and Indian Housing. Washington, DC: U.S. Government Printing Office, 1990 rev. 1991. pp. 1-161, Appendices.

10.10. "Lead," Code of Federal Regulations 29 CFR (7-1-90 Ed.), Pt. 1910.1025, 1991, pp. 156-194.

10.11. "Lead," Code of Federal Regulations 29 CFR (6-24-93 Ed.), Pt. 1926.62, 1993, pp. 186-223.

10.12. Pace Environs, Inc.: Comparing Test Results for Lead-Based Paint on Painted Surfaces. Using Four Different Methods. Cary, NC: Pace Environs, Inc., January 8, 1993.

10.13. HybriVet Systems, Inc.: Lead Check™ Swabs Lead Test Kit Instruction Manual. Framingham, MA: HybriVet Systems, Inc., 1992.

10.14. Sensidyne, Inc.: Lead Alert™ Easy to Use Professional All in One Test Kit. Clearwater, FL: Sensidyne, Inc., 1993.

10.15. Thomas Klingner: "Considerations to be Taken into Account Regarding Exposure to Lead and other Toxic Materials." March 14, 1994. [Private Conversation]. Thomas Klingner, Colormetric Laboratories, 1261A Rand Road, Des Plaines, IL 60016.

10.16. Farfel, M.R., P.S.J. Lees, D. Bannon, B.S. Lim, and C.A. Rohde: Comparison of Two Cyclone-Based Collection Devices for the Evaluation of Lead-Containing Residential Dusts. Appl. Occup. Environ. Hyg. 9:212-217 (1994).

10.17. Driscoll, J.N., C. Wood, T. Powell, and J.S. Askew: An Extractive X-Ray Fluorescence Method for Field Screening Lead Paint Sites. Appl. Occup. Environ. Hyg. 9:206-211 (1994).