Name Cocobolo
Location Central America
Texture/Grain Medium/Open
Specific Gravity 1.10
Hardness Very Hard
Strength Very Strong
T/R Stability 5.7/2.9%

 

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ike many other plants, trees produce antibiotic chemicals to protect themselves from the organisms that cause disease and decay. These may also have an unpleasant effect on craftsmen who come in intimate contact with the wood.

 

WOOD-RELATED AILMENTS
Chemicals in wood have been found to cause or contribute to:

bullet

Nausea and headaches

bullet

Kidney and liver malfunction

bullet

Skin rashes and eye irritation

bullet

Asthma, emphysema, and other respiratory problems

bullet

Nasal cancer

This can be a problem for craftsmen, but it shouldn’t be blown out of proportion. Not everyone is affected by the potentially toxic chemicals in wood. Only 2 to 5 people out of 100 develop an unhealthy sensitivity to them, although woodworkers have an increased risk. And not many woods contain enough chemicals to be dangerous. There are just a few troublesome species, listed in the chart below.

IRRITANTS AND SENSITIZERS
There are two common ways that a wood may affect your health — as either an irritant or a sensitizer. Irritants bother most craftsmen, at least to a small degree. These effects may be mechanical rather than chemical — fine sawdust tickles your nasal passages and makes you sneeze. More often, though, it’s the chemicals in the sawdust that irritate you. The tannic acid in oak, for example, is a powerful irritant.

Sensitizers affect only those people who are allergic to them. Allergic reactions range from a runny nose and watery eyes to hives and asthma. Furthermore, repeated exposure often causes greater sensitivity, and the reaction becomes more severe.

A very few woods contain chemicals which cause systemic reactions, affecting the stomach, nerves, kidneys, even the heart. Oleander and yew, for example, contain chemicals similar to digitalis, a heart drug.

LIMITING EXPOSURE
What can you do to limit your exposure? Quite a bit.

bullet

Wear a dust mask. The most common way you get wood chemicals into your body is by inhaling them.

bullet

Use a dust collector when running power tools.

bullet

Ventilate your shop and clean it frequently.

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Keep your shop cool. Heat causes you to perspire. This mixes with sawdust and releases more toxic chemicals.

Just as important, you should not expose other people. Never use potentially toxic woods to make cutting boards, bowls, or eating utensils. Also avoid them for toys, jewelry, and items that someone might put in their mouth or rub against their skin.

One more precaution: See a doctor if you have recurrent nosebleeds or persistent sinus infections when you work wood. These are causes for special concern.
 


I've found that the most effective and comfortable way to protect myself from sawdust (especially during dust-intensive tasks like sanding) is to wear a positive-pressure face mask. A fan blows filtered air over my face at all times. The air leaks out around the edges of the mask, preventing sawdust from entering. This is an older model with the fan, filter, and batteries in a fanny-pack. Newer units incorporate the filter and fan – sometimes even the batteries – in the helmet. There are are also effective positive-pressure "partial" masks that look very much like ordinary dust masks.*

WOOD SPECIES

REACTION

PART OF BODY

POTENCY

SOURCE

OCCURRENCE

Bald Cypress

sensitivity

respiratory

+

dust

 rare

Balsam Fir

sensitivity

eyes, respiratory

+

leaves, bark

 common

Beech

sensitivity,
nasopharyngeal cancer

eyes, skin
nose, throat

++
?

dust, leaves, bark
dust

 common
 unknown

Birch

sensitivity

respiratory

++

dust, wood

common

Black Locust

irritation

eyes, skin

+++

leaves, bark

common

Blackwood

sensitivity

eyes, skin

++

dust, wood

common

Boxwood

sensitivity

eyes, skin

++

dust, wood

common

Cashew

sensitivity

eyes, skin

+

dust, wood

rare

Cocobolo

sensitivity, irritation

eyes, skin, respiratory

+++

dust, wood

common

Dahoma

irritation

eyes, skin

++

dust, wood

common

Ebony

sensitivity, irritation

eyes, skin

++

dust, wood

common

Elm, Red

irritation

eyes, skin

+

dust

rare

Goncalo Aves

sensitivity

eyes, skin

++

dust, wood

rare

Greenheart

sensitivity

eyes, skin

++

dust, wood

common

Blackwood (Surinam)

sensitivity

eyes, skin

+++

dust, wood

common

Hemlock

nasopharyngeal cancer

respiratory

?

dust

unknown

Iroko

sensitivity, irritation,
pneumoitis alveolotis

eyes, skin, respiratory

+++

dust, wood

common

Mahogany, Honduras

sensitivity, pneumoitis
alveolotis

skin, respiratory

+

dust

unknown

Mansonia

sensitivity, irritation,
nausea, malaise

eyes, skin
systemic

+++
+

dust, wood
dust

common
 unknown

Maple (Spalted)

sensitivity, pneumoitis
alveolotis

respiratory

+++

dust (contains
mold)

common

Mimosa

nausea, malaise

systemic

?

leaves, bark

unknown

Myrtle

sensitivity

respiratory

++

dust, leaves, bark

common

Oak

sensitivity, nasopharyngeal
cancer

eyes, skin
nose, throat

++

dust, leaves, bark

 rare

Obeche

sensitivity, irritation

eyes, skin, respiratory

?

dust, wood

 common

Oleander

direct toxicity, nausea,
malaise, cancer

systemic

++++

dust, wood,
leaves, bark

 common

Olivewood

sensitivity, irritation

eyes, skin, respiratory

+++

dust, wood

 common

Opepe

sensitivity

respiratory

+

dust

 rare

Padauk

sensitivity,
nausea, malaise

eyes, skin
systemic

+
?

dust, wood
dust, wood

 rare
 unknown

Pau Ferro

sensitivity

eyes, skin

+

dust, wood

 rare

Peroba Rosa

irritation, nausea, malaise

respiratory, systemic

++

dust, wood

 unknown

Purpleheart

nausea, malaise

systemic

++

dust, wood

 common

Quebrach

irritation
nausea, malaise,
nasopharyngeal cancer

respiratory
systemic
nose, throat

++

?

dust, bark, leaves
dust
dust

 common
 unknown
 unknown

Redwood

sensitivity, pneumoitis
alveolotis,
nasopharyngeal cancer

eyes, skin, respiratory

nose, throat

++

?

dust

dust

 rare

 unknown

Rosewoods

sensitivity, irritation

eyes, skin, respiratory

++++

dust, wood

 common

Satinwood

irritation

eyes, skin, respiratory

+++

dust, wood

 common

Sassafras

sensitivity,
direct toxicity,
nausea, malaise,
nasopharyngeal cancer

respiratory,
systemic

nose, throat

+
+

?

dust
dust, wood,
leaves, bark
dust

 rare
 rare

 rare

Sequoia

irritation

respiratory

+

dust

 rare

Snakewood

irritation

respiratory

++

dust, wood

 rare

Spruce

sensitivity

respiratory

+

dust, wood

 rare

Walnut

sensitivity

eyes, skin

++

dust, wood

 common

Wenge

sensitivity

eyes, skin, respiratory

++

dust, wood

 common

Willow

sensitivity, nausea, malaise

respiratory, systemic

+

dust, wood, leaves, bark

 unknown

Western Red Cedar

sensitivity

respiratory

+++

dust, leaves, bark

 common

Teak

sensitivity, pneumoitis
alveolotis

eyes, skin, respiratory

++

dust

 common

Yew

irritation
direct toxicity, nausea,
malaise,
nasopharyngeal cancer

eyes, skin
systemic

nose, throat

++
++++

++++

dust
dust, wood

dust

 common
 common

 common

Zebrawood

sensitivity

eyes, skin

++

dust, wood

rare

Note: The information in this chart is based on data collected by Robert Woodcock, RN, BSN, CEN

Glossary of Terms

bullet

Irritation The wood species acts as an irritant, causing itching, rashes, watery eyes, and other uncomfortable reactions.

bullet

Sensitivity The wood species acts as a sensitizer, causing people to develop allergic reactions after repeated exposure.

bullet

Direct toxicity Chemicals (called extractives) in the wood species are poisonous.

bullet

Nausea, malaise Exposure to the wood species cause flu-like symptoms.

bullet

Systemic Reactions are not confined to a specific body part; they affect much or most of the biologic system.

bullet

Nasopharyngeal cancer A cancer that affects the back of the throat where the nasal passages open into it.
 

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*Indicates that you can enlarge a photo by clicking on it. To reveal the information in a "Superphoto," first enlarge it and then move the cursor over it.

 "Abundant to all the needs of man, how poor the world would be without wood."
Eric Sloane in Reverence for Wood

 

Wood and Woodworking Materials/Hardwoods and Softwoods/Health Hazards and Toxic Woods,
part of the Workshop Companion, essential information about wood, woodwork, and woodworking
necessary to woodworkers and practitioners of the wood arts
to become competent craftsmen.
By Nick Engler.

Copyright © 2009 Bookworks, Inc..