Naphthol Red Dark

PR23

Alternate Name

Naphthol Red Dark AS-BS

Pigment Description

Naphthol Red Dark is one of several napthols out there. A pigment whose lightfastness descends to ASTM IV or even ASTM V in gouache- the lowest lightfastness category for artist paints- is also flagged for potential health problems. It is currently found in six acrylic paints made by major manufacturers and at least one watercolor.

In Monona Rossol's writing, this is a suspected carcinogen, and has caused kidney damage in rats, along with metabolizing to cause something related to methemoglobinemia, so please consult her work for more information.

Resources

PR23 pigment data from David G. Myers, The Color of Art Pigment Database, Artiscreation.com

Information about PR23 from Bruce MacEvoy, Handprint Guide to Watercolors, General information about this class of pigments from Handprint,

Rossol, Monona. The Artist's Complete Health and Safety Guide. New York, NY : Allworth Press, 2001. The book is rather dated, updated information is available from her website.

Stats

Lightfastness

Poor, may be as low as ASTM IV

Transparency

Semi-Transparent

Toxicity

Thought to be category of lesser concern

Treat all pigments and paints with studio safety protocols.

Chemical Name

Monoazo: 3-hydroxy-2-naphthanilide

Dry Pigments listing PR23

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