Seventeen chromium-allergic adults were patch tested with aqueous potassium dichromate at 1, 10, 100, and 1000 ppm chromium, with and without a pretreatment irritant, and most then received repeated open doses at 5, 10, 20, and 50 ppm chromium. On normal skin the authors place the patch threshold at 10 ppm. With irritant pretreatment, 2 of 17 reacted at 1 ppm. In the open test, 3 of 15 reacted at 5 ppm. The paper does not analyse chromium levels in the household products discussed in the introduction.
Key numbers
Figures below are copied as printed. Units are not converted. Species are not merged.
| Analyte | What was reported | Value | Unit | Basis | Where |
|---|---|---|---|---|---|
| Cr | aqueous dilutions of potassium dichromate that were equivalent to the following concentrations of Cr: 1000, 100, 10 | 1 | ppm Cr | occluded patch for 2 days | Part 1 and Table 3, p. 2 |
| Cr | aqueous dilutions of potassium dichromate that were equivalent to the following concentrations of Cr: 1000, 100, 10 | 10 | ppm Cr | occluded patch for 2 days | Part 1 and Table 3, p. 2 |
| Cr | aqueous dilutions of potassium dichromate that were equivalent to the following concentrations of Cr: 1000, 100, 10 | 100 | ppm Cr | occluded patch for 2 days | Part 1 and Table 3, p. 2 |
| Cr | aqueous dilutions of potassium dichromate that were equivalent to the following concentrations of Cr: 1000, 100, 10 | 1000 | ppm Cr | occluded patch for 2 days | Part 1 and Table 3, p. 2 |
| Cr | ROAT 5 ppm | 5 | ppm Cr | open application twice daily for up to 1 week | Table 4 and Methods, p. 3 |
| Cr | ROAT 10 ppm | 10 | ppm Cr | open application twice daily for up to 1 week | Table 4 and Methods, p. 3 |
| Cr | ROAT 20 ppm | 20 | ppm Cr | open application twice daily for up to 1 week | Table 4 and Methods, p. 3 |
| Cr | ROAT 50 ppm | 50 | ppm Cr | open application twice daily for up to 1 week | Table 4 and Methods, p. 3 |
| Cr | Potassium dichromate (99%) | 99 | % | as supplied | Materials, p. 2 |
| Cr | on normal skin, the patch test threshold was 10 ppm chromium | 10 | ppm chromium | elicitation threshold, not a measured product concentration | Abstract, p. 1 |
| Cr | in the presence of an irritant (sodium lauryl sulfate) the threshold was closer to 1 ppm, 2/17 subjects giving 1+ | 1 | ppm | elicitation on pretreated skin | Abstract, p. 1 |
| Cr | 8/14 individuals failed to react to 50 ppm, whilst 3/15 reacted to 5 ppm | 3/15 reacted to 5 ppm; 8/14 failed to react to 50 ppm | ppm Cr | open application | Abstract and Table 4, p. 1 |
Methods (brief)
Patches stayed on for 2 days and were read at day 2 and day 4. Pretreatment was 0.2% sodium lauryl sulfate for 1 day. Open applications used potassium dichromate in water containing 1.0% sodium lauryl sulfate, twice daily for up to 1 week, on the antecubital fossa. Solutions were coded so the reader did not know which site had the higher concentration. Potassium dichromate purity is printed as 99%.
Evidence fitness
These data support Closed patch concentrations applied were 1, 10, 100, and 1000 ppm Cr, on normal skin and on skin pretreated with 0.2% sodium lauryl sulfate; Repeated open application concentrations were 5 and 10 ppm Cr, then 20 and 50 ppm Cr in volunteers who had not already reacted; The authors state a patch threshold of 10 ppm chromium on normal skin and closer to 1 ppm when an irritant was present (2 of 17 with 1+ reactions at 1 ppm).
They do not support Does not measure chromium in household products, detergents, or cement; Does not report urinary or blood chromium; Does not distinguish a measured Cr(III) dose; the salt used was potassium dichromate; A 5 ppm maximum and 1 ppm target for consumer products are recommendations the authors attribute to an earlier task force, not concentrations measured in this experiment.
Limitations
Table 3 scores are clinical grades (0, ?, 1+, 2+, 3+, 4+), not concentrations, so they are not copied as metal values. The discussion says the second open-application phase used 25 and 50 ppm, while the methods and Table 4 print 20 and 50 ppm. The abstract’s 8/14 who failed to react at 50 ppm does not match a simple reading of Table 4, where several people were not tested at 50 ppm. A cited 89 ppm potassium dichromate in bleach is from earlier literature and is not ledgered.
Related evidence
Update history
No substantive edit history is available in this build. The full commit record is available in git.